Show HN: Termtosvg – Record terminal sessions as SVG animations - <AUTHOR> https://github.com/nbedos/termtosvg <comment><USER2> This is pretty awesome. I'm a big fan of both SVG animations and terminal recorders, so this is right up my alley. I previously built a small library called _svganimator_ for creating smooth animations between static SVG images [1], used generated SVG animations to help design the Wayback Machine loading animation [2], and also put together a fairly comprehensive comparison of terminal recording solutions [3]. I'll need to update the comparisons to include _termtosvg_ , I can't wait to try it out and see what the file sizes look like.

As others have mentioned, the major issue with SVG animations is that Microsoft doesn't plan to ever include support for them in Edge. This means that you either need to create fallbacks specifically for Microsoft browsers, or to disregard that portion of the market on your website. It's a real shame because SVG/SMIL allows you to create high quality animations which require a fraction of the bandwidth that would be necessary for comparable GIF or video files.

[1] - [https://github.com/sangaline/svganimator](https://github.com/sangaline/svganimator)

[2] - [https://intoli.com/blog/designing-the-wayback-machine- loadin...](https://intoli.com/blog/designing-the-wayback-machine-loading- animation/)

[3] - [https://intoli.com/blog/terminal- recorders/](https://intoli.com/blog/terminal-recorders/)

<comment><AUTHOR> OP here. Sadly, SVG file size is not as small as I'd want it to be. The main problem is that a few attributes (x, y and lengthAdjust) have to be repeated on each text tag to position each character at the right place. I can't use CSS for this since those attributes are not styling attributes.

Using SVG definitions efficiently to avoid duplication is also not as easy as I thought it would be.

I have a few ideas on how to reduce file size, this is the next improvement I'm planning to work on.

For the examples shown at [1], file size ranges from 56kB to 252kB, the worst case scenario being lots of single characters with different colors.

[1] [https://github.com/nbedos/termtosvg/blob/master/examples/exa...](https://github.com/nbedos/termtosvg/blob/master/examples/examples.md)

<comment><USER3> How about with gzip? I feel like SVG files should compress well. I'd imagine most HTTP servers already just use gzip for these files.

<comment> wes-k Was curious myself. 252K -> 17K. Yes it compresses well :)

</comment></comment></comment></comment><comment><USER4> Excellence! The README reads: "I really like the clean look of SVG animations and I also wanted to see how this solution would hold out against other attempts at terminal recording such as asciinema."

But how does it compare? Is the size smaller, is it more efficient?

<comment><USER5> Animated SVG animations (really just an svg element + animated css) are significantly smaller, more efficient, and crisper than equivalent GIF animations. I wrote about the difference between the two here: [https://hackernoon.com/presenting-your-code-beautifully- fdba...](https://hackernoon.com/presenting-your-code-beautifully-fdbab9e6fb68)

As I explained in the above article, this is already possible with asciinema + svg-term-cli ([https://github.com/marionebl/svg-term- cli](https://github.com/marionebl/svg-term-cli)).

The one downside with animated SVGs is that they're not as compatible to be included anywhere as GIFs since they're really just html snippets.

<comment><USER6> You're competing with webm / mp4 not gif though.

Editing the HTML attribute to width=2000% is pretty sweet however because it's a vector.

I'm guessing if the example wasn't in an image tag I could select the text too?

<comment><USER7> If you click on the example image to view it in a new tab, you can select the text there. It could be improved, afaict you can only select a single line of text at a time and if you select the current line being typed then the selection is cleared when that line is modified.

</comment></comment></comment></comment><comment><USER8> This is great for many of the same reasons that asciinema is great -- smooth animation and selectable text. The resulting svg is orders of magnitude smaller than a gif would be.

How hard would it be to add some sort of pause button to aid in selecting from the capture? Also, it appears you can only select when you are viewing the image directly, not when it is embedded via an <img> tag. Is that fixable? I guess maybe an <iframe> might work, but I haven't played with it yet.

<comment><USER9> I wonder if you could just use a javascript button to pause the animation and if that would make the text selectable.

</comment></comment><comment><USER10> The primary casualty of using SVG animations is IE/Edge support; SMIL is not currently planned: [https://developer.microsoft.com/en-us/microsoft- edge/platfor...](https://developer.microsoft.com/en-us/microsoft- edge/platform/status/svgsmilanimation).

It would be good to adjust the failure mode so that if SMIL is not supported then at least a meaningful frame (probably the last, though scrolling makes it difficult to decide!) is shown, rather than just a blank rectangle.

<comment><USER11> Jesus, it's 2018 and they still can't even figure out how to implement animated PNGs? Real browsers had this 10 years ago. What the hell is wrong with Microsoft? Are they really just so incompetent, or is there a more insidious business reason why they don't want more animated formats on the web?

<comment><USER12> SMIL is something quite different and much more complex, than "animated PNGs"

<comment><USER13> Is complexity a reasonable excuse for one of the world's largest corporations to forego a feature in their flagship browser that every other browser has implemented?

</comment></comment></comment></comment><comment><USER14> The example animation looks broken in Safari (including Tech Preview 59), works in Chrome 67 (of course), and in Firefox 61.

[Edit: This seems to be a macOS/driver bug affecting only some models]

<comment><USER15> I don't see any problems with Safari 11.1.1 on macOSX or on mobile Safari on my iPhone.

<comment><USER14> Right. It works on my 2013 MacBookPro, but the drawing looks incomplete/broken on my 2015 Retina 5k iMac. Both run macOS 10.13.5.

</comment></comment></comment><comment><USER16> Sadly, I will not replace asciinema+svg-term-cli by termtosvg, because termtosvg takes the terminal size into account when recording, not when rendering. It means that I have to resize my terminal before recording, and that I will not be able to resize it differently for rendering. So if lines are wrapped, I cannot change the width to de-wrap them in the resulting SVG.

Asciinema does not care about your terminal size when recording. In fact you can even reduce it or hide it (if you automate the input). Then you render it with svg-term-cli with the width you feel it is best.

</comment><comment><USER17> I'm very impressed - it combines two of my favourite technologies, Python and SVG. Three, in fact - including terminal. I will be watching it and tinkering with it.

It's written in modern Python and well documented. However, some functions are a bit monolithic: [https://github.com/nbedos/termtosvg/blob/master/termtosvg/te...](https://github.com/nbedos/termtosvg/blob/master/termtosvg/term.py#L215)

</comment><comment><USER18> Cool. It is not very clear from the description so I will ask:

What are the advantages over "asciinema"?

At the moment I only see that it does not require a specific player (javascript for the web), on the other hand it seems you are not able to pause the "execution".

<comment><USER19> I think standalone is the most outstanding advantage. Many recordings of terminal are using asciiema or youtube, those links in a github readme.md file is a static screenshot instead of animated one, you have to click the link to watch the animation.

You can view the animation without javascript enabled, and it's media type is image, you don't even need to convert it to base64 to use it. It's like gif but relatively smaller and with more colors, and it's Scalable Vector.

</comment></comment><comment><USER20> What're people using tools like this for? I see the usage surely when demonstrating _something_ in the terminal - and many times used for showcasing projects and tools. Are you using the recordings for other purposes, like to document work and share progress with your team + manager for instance for work you're doing during a sprint (good for demo'ing things at the end of the sprint too).

<comment><USER21> It's good for right-way vs wrong-way demonstrations. If I just copy the text out of my terminal and say "this is how we used to do it; this is how we should do it/will do it now" and paste it in a jira ticket, not many people will take the time to read and understand. Gifs are more accessible I guess.

<comment><USER22> Maybe it's just me, but I can't stand having to wait to watch someone slowly type something when all I want to to is know the command or understand what some output should look like.

Similarly, I've never seen this sort of thing used professionally, just on blogs and project demos.

<comment><USER12> It really should have a timelinecontrol ..

</comment></comment></comment></comment><comment><USER23> A few weeks ago I tried to convert one of my asciinema recordings to a SVG with svg-term-cli [1], but the result had big problems with some browsers, so I took the more mainstream gif approach again.

Anybody tried termtosvg with different browsers yet?

[1]: [https://github.com/marionebl/svg-term- cli](https://github.com/marionebl/svg-term-cli)

</comment><comment><USER24> SVG is one of those technologies that never really caught on, even though it would have made life much easier for everyone.

<comment><USER12> If the standard would have been clear and simple - then maybe yes. But in my opinion it was and still is, a huge mess. It somewhat works now, but ... it is a subset, that works. But it is not evil intention(nor the fault of Adobe or now Microsoft), that the love for SVG is not the greatest.

</comment></comment><comment><USER25> The example recording renders super smoothly in FF v61.0 and Chrome v67.0, but stutters in Safari running on an OS-X 'High Sierra' machine.

That said, I'm absolutely loving this as the file size and the memory footprint of this SVG is super-small relative to what a .gif of the same content would be. Great work!

</comment><comment><USER26> You could differentiate more from asciinema by building editing tools around the recording (like cutting or embedding the recording in stock frames like in [https://shotsnapp.com](https://shotsnapp.com))

<comment><USER26> Have a look here also: [https://github.com/cirocosta/asciinema- edit](https://github.com/cirocosta/asciinema-edit)

</comment></comment><comment><USER27> This is extremely cool, and will be useful.

One bug I noticed is that it seems to break virtualenv which is made with --system-site-packages its not finding the modules

<comment><AUTHOR> Thanks! I will look into the virtualenv problem, but if you can spare the time could you please open an issue and include the exact steps to reproduce the error?

[https://github.com/nbedos/termtosvg/issues/new](https://github.com/nbedos/termtosvg/issues/new)

</comment></comment><comment><USER28> Amazing stuff. And in very readable Python!

</comment><comment><USER29> Awesome! It sounds like browser support may currently be an issue, but I really like the idea :)

</comment><comment><USER30> This is super awesome, but will there ever be an ability to pause/rewind/scrub?

<comment><USER31> Well, the animation is inherent to the SVG, so either browsers would need to support that, or some kind of JavaScript library is needed to extract that (probably giving Edge animation support while it's at it)

</comment></comment><comment><USER32> If only ffmpeg->mp4 instead of svg...

I had just thrown together a typescript bash script to record IRC with timing for later playback and sync with a podcast, the trick is the rendering step: in theory it could be done on a canvas with native ffmpeg drawtext, but the invocation is super gnarly.

</comment><comment><USER33> Pretty Cool</comment>


IOS 6 and Facebook deep integration : creepy? - <AUTHOR>

Does any body see any issues with that? Things could be worse from a privacy perspective: a Facebook OS. But the bigger question is is this the right direction for us as a society ? Is this the right direction for capitalism. The argument should be looked from both sides. <comment><USER2> I actually just don't get why, architecturally, a platform should have any incentive (besides business) to favour this app or that app.

You can see how this becomes complicated when Twitter & FB both recieved integration, as they both directly compete with each other in a number of spaces.

This kind of deep integration should've been done at an API level, where the user has more control over what kind of apps _are_ deeply integrated, rather than the closed system that Apple supports.

</comment><comment><USER3> What are your arguments against it? As a society I don't think that it affects us. We're simply taking things that people already did on Facebook and making them easier to do. Facebook exposed all of this through their API so there were plenty of apps implementing this anyways. It's just one less layer.

In terms of capitalism, I suppose that remains to be seen...

<comment><AUTHOR> Well one argument against it is privacy. by companies zeroing in on the source of the information and coupled with critical mass consumers don't really have a choice unless being a total outcast. Between apple and Facebook they know a lot about you and your habits in return for giving you a place to upload pictures and throw cows at your friends. Besides the occaisonal desIre to voyeur.

From a business perspective the platform gives an opportunity to use InfOrmation creatively and develop products and sell them. I don't see how such a personal information based business model can sustain for two decades unless it's ok for us as a society to live as a statistic because of the sheer amont of data that has been created and analyzed on individuals and groups.

</comment></comment><comment><USER4> It's been on Windows Phone for over a year and it's the best thing ever :) Not creepy at all, but rather highly practical.</comment>


Women Prefer Poaching - <AUTHOR> http://www.overcomingbias.com/2009/08/women-prefer-poaching.html <comment><USER3> A woman can only bear a single man's child in a 9 month period. A woman with a large number of male suiters is _theorectially_ less appealing, since the chance of successful mating (where successful -> results in offspring in the near future) is very low (assuming each man has an equal chance, it's essentially 1/(#ofSuiters) ). In reality, the energy cost of impregnating a woman is so low that it doesn't really matter that much, since he doesn't actually have to bear the child.

A man can impregnate many woman in this same period of time. All of these woman have a good chance of creating offspring, so the main concern of an individual woman is finding a man who will be able to provide for her child. This is a complex requirement - it isn't necessarily sufficient to just look at a man to gauge his ability to secure resources. Also, the energy cost of becoming pregnant is extremely high for a woman. Therefore, the woman reacts based on a large number of variables. She also assumes that other woman are searching for a man based on similar requirements, so the fact that a man is surrounded by other woman increases his value as a potential mate.

I realize that this simplifies things quite a bit, but I think the fundamental argument is sound.

<comment><USER4> Completely anecdotal, but kind of along similar lines: I have heard from female friends and and other less personal sources that often times women feel more comfortable around men they don't know who have an observable female partner because it indicates (if even only on a near unconscious level) that this man is most likely "safer" than a man they don't know who does not have a partner. That is, the man's female companion has "tested the water", he's likely not a serial killer, by having a partner he's demonstrating right there and then that he can commit to more than a one night stand etc.

<comment><USER5> Little do your female friends know that the only reason that woman is with me is because I have the antidote.

<comment><USER4> Hence the qualifier: _likely_ not a serial killer. :D

</comment></comment></comment></comment><comment><USER6> "Similarly, a person who has been unemployed for a long time may have a hard time finding a new job - even if they are highly skilled and qualified. Potential employers attribute wrongly the person's lack of employment to the person rather than the situation. This causes the potential employers to search more intensively for flaws or other negative characteristics that are "congruent" with or explain the person's failure and to discount the applicant's virtues."

<http://en.wikipedia.org/wiki/Social_proof>

<comment><USER7> Social proof doesn't explain the result adequately; to wit:

 _Conversely, men rate women as less desirable when they are surrounded by other men, compared to being alone or surrounded by other women._

<comment><USER6> Social proof can't explain it but I've known very few individuals who have the guts to approach a party of mixed sexes (e.g. who are couples - when it's all women - you can assume they're just socializing, not dating (usually)). Actually, it doesn't matter whether it's all women or mixed - <USER2> intimidating.

The times I've done it / the first twenty seconds after you have broached their airspace is among the most scary and exhilirating experiences. The more women, the better. Do not hover!

For bonus points, sidle over and drag a chair loudly from one side of a room to where they are and _sit down_ (presuming they are seated, you have most likely pulled off the icebreaker that needs no icebreaker)

</comment></comment></comment><comment><USER8> Looks like VC's and women have something in common.

<comment><USER9> The fact that _someone_ likes you is a badge of value. Social proof.

This is also why guys that go to bars with friends have a significantly lower chance of being labeled "creepy" than a guy that goes by himself.

<comment><USER6> > being labeled "creepy

I've noticed that when I go somewhere with a friend, even if just one, I feel like I can hang out forever. While, if I were to go to a bar by myself, even though that's easy to do, it's not fun - I feel über self conscious (everyone is looking at me / even though that is probably your false perception).

When you go to a bar by yourself, you have to invest a lot of your energy to _initially_ meet people (think of the times when you've been travelling and in a place where you know no one).

And, on the social side, when I am out with a female friend, I feel even more confident and feel like I have license to flirt shamelessly with near everyone.

I feel going out with friends can give you the support base to go out and venture. However, too many friends can devolve into the classic circle-the- wagons formation. Of course, there is the social hack of working the room that nearly always works and requires fearless action: start with one, engage him/her, offer him/her an opportunity to approach with him/her to a group or leave, engage the group confidently, wave at someone in another group, etc. Done confidently and charmingly, it is quite a feeling / to bootstrap yourself from a loner to someone other people are looking at and wondering 'who is this guy?'

</comment></comment></comment><comment><USER10> "Research on human preferences does show that women rate men as more desirable when they are surrounded by other women, compared to being alone or surrounded by other men. Conversely, men rate women as less desirable when they are surrounded by other men, compared to being alone or surrounded by other women."

In other words, men are undesirable in heterosexual culture. So we conclude that, if you're a guy, your only hope is to find a hot bisexual girlfriend and then surround yourself by women that she likes.

</comment><comment><USER11> This study of the "Wedding Ring Effect" (abstract only) suggests otherwise:

<http://www.springerlink.com/content/hn2ufdx4rruyllnc/>

 _The results show that women do not find men signaling engagement, or being perceived as having a partner, more attractive or higher in socioeconomic status. Furthermore, signs of engagement did not influence the women's reported willingness to engage in short-term or long-term relationships with the men._

<comment><USER12> Interesting. Another study with a different finding. Now there is some scope for methodological discussion about how the data were gathered and interpreted.

</comment></comment><comment><USER13> EDIT: A simple proof to this would be to set your facebook profile to "In a relationship" and go out and add ten random beautiful women as friends. Do the same with "Single" and you will end with significantly lower amount of "accepted".

<comment><USER14> That's not really proof of this. Randomly friending someone of the opposite gender is usually interpreted as a creepy attempt to pursue someone. If they're in a relationship, that motive has to be incorrect. Maybe it's someone you know from somewhere, or someone who likes your work. In that mindset, accepting the request is far more likely.

<comment><USER13> The way I understood this article is that women are more interested in guys who are not single whether they know him or not. This experiment will prove just that.

<comment><USER14> The experiment doesn't measure interest; it measures the likelihood of accepting a friend request. Accepting a friend request is not strong evidence of romantic interest due to the interactions I described.

</comment></comment></comment></comment><comment><USER15> It's a pretty well know effect predicted by evolutionary psychology (and confirmed in several species). Basically, no matter what strategy female use to identify good mates it can be improved by peeking at what other female do.

"Poaching" is also very cheap and relatively safe (as far as identifying goes), so it would be more popular with females/males who don't have other good criteria.

</comment><comment><USER16> _"... Conversely, men rate women as less desirable when they are surrounded by other men ..."_

I think "Flight of the Concords" got this one right (nsfw) ~ <http://www.youtube.com/watch?v=9Wl_uQOABxg>

<comment><USER17> Flight of the concHords is great stuff, check out 'jenny' and 'business time' too if you have a minute or ten... and 'the humans are dead'

<comment><USER18> "If you're into it" is also pretty sweet. For several meanings of the word. Kind of.

<http://www.youtube.com/watch?v=pY8jaGs7xJ0>

</comment></comment></comment><comment><USER12> Upvoted for interesting implications.

I'm not sure if the study design or sample size

<http://norvig.com/experiment-design.html>

reported here inspires confidence in the conclusion, but this would definitely be an issue worth investigating some more. I'm not sure how many men would guess this, or for that matter how many women would guess what this article says about men. I can think of one example of a woman I knew (back when I was single) who seemed to be signalling to me that she wanted me to "poach" her by telling me she had a boyfriend. But to me that was just off-putting. (I was already put off from a romantic relationship with her--I knew her strictly through studies we were both pursuing at the time.)

<comment><USER19> > I'm not sure how many men would guess this, or for that matter how many > women would guess what this article says about men

Really? I've always believed it to be common wisdom that some women strongly prefer men in relationships.

</comment></comment><comment><USER20> _> Across ten world regions, 57% of men and 35% of women indicated they had engaged in an attempt at mate poaching, … people who mate poach are more likely to be low in agreeableness and conscientiousness than those who do not._

Interestingly, it seems that while women prefer it, they do it a whole lot less than men. And that men that are in a relationship may be more attractive, but the women they will get will on average be less nice...

<comment><USER21> If you steal someone, then all you get is someone who is easily stolen. It's never worth it.

<comment><USER20> And if you let yourself be stolen, all you get is a thief... Honesty is really a good policy here.

</comment></comment></comment><comment><USER22> There's a bit about this in _The Book of Laughter and Forgetting_, roughly to the effect that women don't want handsome men, they want men with beautiful consorts.

<comment><USER23> Crazy. I just read that book about a month ago, but certainly didn't expect to see it mentioned here. Fantastic book

</comment></comment><comment> onreact-com Why don't submit the source instead, it's just a citation? <http://www.synergy-pr.com/press/MelissaBurkley,PhD/51/800/0></comment>


BladeRF - USB 3.0 Software Defined Radio - <AUTHOR> http://www.kickstarter.com/projects/1085541682/bladerf-usb-30-software-defined-radio

<comment><USER2> Very interesting. From the specs it seems like a hefty step up from the cheap dealextreme DVB stick.</comment>


Ask HN: LLC with International Founder - <AUTHOR>

I'm not entirely sure if this question has been answered before, but I've searched around for a while and cannot find anything on the subject.
I'm looking to form an LLC in the next couple of week for an up-and-coming product a friend of mind and I are working on. Problem is, I live in the US and he lives in the UK. Does the international aspect of my co-founder increase the complexity of government taxing? Has anyone had any experience with this scenario?
Any help would be greatly appreciated. <comment><USER2> You should eventually speak to an expert. When? It depends on how quickly you expect to yield net revenues and need to distribute profits.

If you expect to run in the red for a while and once you show some traction may bring in investors, then I would follow my "rule of lazy paperwork":

1 - An outside investor will want you to restructure into an investment compatible vehicle, not an LLC most likely. So treat you LLC as an operating vehicle while you bootstrap. The less complex things are in the beginning, the less complex it will be when you need to restructure.

2 - For any startup partner you can write a simple contract that says the intellectual property ownership is shared by your persons and will be injected into some new entity in the future. In the meantime, you create another one- page contract that licenses this jointly owned IP to your operating LLC.

3 - You can't easily have both UK and U.S. rules. I suggest your partner accept that he is enjoining a U.S. (really, your state) ruled set of contracts and live with it.

4 - In the future, you can assign your IP into an offhore entity (e.g. Caymans) and then redeploy those licensing contracts your LLC already has. At this point you would also make the U.S. LLC a wholly owned entity of the offshore entity and have all you and your partner's shareholdings in the offshore entity.

The above gives you an operating LLC so you get some protection and can have bank accounts, etc... Until you need to distribute any earnings, you can keep it simple and with little paperwork.

As always, IANAL, this is simply how I might approach the problem.

</comment><comment><USER3> You will need to engage someone to help file the LLCs taxes, so you should engage this person now and start asking your question before you incorporate.

Among other things, consider the following:

1\. If this is the type of project that is intended to be VC-funded in the future, you should start with a corporation, not an LLC. (Keep in mind that an S corp can't have non-U.S. residents.)

2\. If the LLC is a flow through entity, the UK person may have income "effectively connected to a U.S. trade or business," which may subject them to U.S. income tax at the same graduated rates that U.S. persons pay.

</comment><comment><USER4> It definitely increases the complexity of taxing. Sorry. I know how you feel - I'm an American partnered with (& married to) an Austrian (and we both live in Austria!).

However, I'm fairly sure that the UK and US - like every other major country and the US - have an anti-double taxation treaty. Which probably means that you personally will pay taxes only in the country which has the highest rate (clearly your home country).

IF - and only if - you get good tax advice up front can you reduce your American taxes by carefully structuring the way you take money out of the company.

It's hard to find accountants who are experienced in this. My personal suggestion would be to call Deloit or another big international consultancy.

EDIT: Sorry, I got who's UK/who's US backwards. Advice still stands tho. You can definitely form an LLC with a foreigner, even using an online service, it's just that taxes are a bitch. No way around that.

<comment><USER5> Wait, what? As a citizen I pay double taxes. I get a credit up to ~ $83k, and after that I get double taxed.</comment></comment>


Good Snail Mail API Service? - <AUTHOR>

I've looked at both PostalMethods and Postful. Wondering if there is any more competition out there. <comment><USER2> <https://www.mailfinch.com/api>

<comment><AUTHOR> Yes, this one looks great. Thank-you!</comment></comment>


Show HN: Hacker News Deck – Evening Project - <AUTHOR> https://hndeck.herokuapp.com/ <comment><AUTHOR> Hello HN, This is TwitterDeck for HackerNews. Hope you like it. Thanks for your support.</comment>


Deep Learning from Scratch Part 3: Generalizing Gradient Descent - <AUTHOR> https://jdridgeway.com/deep-learning-from-scratch-generalizing-gradient-descent/ <comment><USER2> Sorry to be pedantic but you should not confuse gradient descent (the procedure to optimize the weights) with the way in which you compute the gradients.

Generalized gradient descent is used when minimizing a function that is not differentiable at all inputs and has nothing to do with deep learning.

<comment><USER3> I urge beginners not to learn these things from blog posts, even if it seems more digestible. Take a reputable textbook and you will be better off. Or take a MOOC, like Andrew Ng's or courses from MIT and Stanford on Youtube. It may look harder, but it has all been carefully didactically structured. It's harder on the long run to learn from a non-expert.

There's so much confusion out there, blog posts confusing cross-entropy with "softmax loss", gradient descent with backpropagation etc. etc.

<comment><USER4> I prefer to combine the approaches. Read blogs to get a general sense of what's worth studying more deeply. Then study it more deeply with a textbook or MOOC. Then read blogs and watch videos to help clarify the concepts that you didn't quite grasp. Usually your understanding will be solid enough by that point that you'll be able to judge the quality of the material pretty well.

</comment></comment></comment><comment><USER5> You should post the links to the other parts at the top of your articles..

</comment><comment><USER6> Grokking deep learning is similar in style and is very accessible if you don't like formulas.</comment>


This chip could be key to the future of AI. - <AUTHOR> https://www.technologyreview.com/s/613305/this-chip-was-demoed-at-jeff-bezoss-secretive-tech-conference-it-could-be-key-to-the-future <comment><AUTHOR> Chip was designed by Vivien Sze's Energy-Efficient Multimedia Systems Group at MIT ([http://www.rle.mit.edu/eems/](http://www.rle.mit.edu/eems/)). Key takeaway:

"Sze's chip is called Eyeriss. Developed in collaboration with Joel Emer, a research scientist at Nvidia and a professor at MIT, it was tested alongside a number of standard processors to see how it handles a range of different deep- learning algorithms. By balancing efficiency with flexibility, the new chip achieves performance 10 or even 1,000 times more efficient than existing hardware does, according to a paper ([https://arxiv.org/abs/1807.07928](https://arxiv.org/abs/1807.07928)) posted online last year."</comment>


Windows Phone 7 Repeats iPhone Flaw - <AUTHOR> http://www.minyanville.com/businessmarkets/articles/apple-blackberry-smartphone-palm-android-iphone/3/17/2010/id/27324?camp=syndication&medium=portals&from=yahoo

<comment><USER2> And yet one of the requirements for being a Windows 7 capable phone is to have a physical "Bing button"</comment>


Deep learning pipeline for orbital satellite data for detecting clouds - <AUTHOR> https://github.com/BradNeuberg/cloudless <comment><USER2> This is neat. We've deployed a 98+% accuracy satellite & aerial cloud detection solution for many years, so I would have the following suggestions:

-Why use AlexNet and not VGG (or Googlenet)?

-Make sure to train on clouds vs desert. There are a lot of instances where their spectral signatures are very close, depending on the satellite.

-Make sure to train on clouds vs snow. They are even more close.

-Dark clouds. This might not show up much unless you're working with the satellite vendor, but there are cloud formations where shadows of clouds project onto other clouds. Very difficult to deal with and NN may be well suited to it.

I would say since it's absolutely possible to get higher accuracy using older methods on this exact satellite constellation, there is definitely room for improvement. Just switching to VGG might even do the trick. But this is a great first step!

<comment><USER3> [Cloudless developer here]

Thanks for all the great suggestions! In terms of your existing 98% accuracy solution, can you point me to more details if possible?

I grabbed AlexNet as its a bit easier to work with and was readily available as a fine tunable model on the Caffe Model Zoo, but you're certainly right that VGG or Googlenet would give more accuracy.

For training on clouds vs snow and deserts, this is a bit more of a proof of concept for now based on the data we had access to (state of California). Someone could certainly scale this up using a larger data set and generating more annotation data with examples of snow and deserts to handle more edge conditions. They would probably want to build Mechanical Turk support into the annotation tool if they did.

Thanks for all the great comments! All of this is open source so contributions using any of these suggestions are certainly possible.

Best, Brad Neuberg

<comment><USER2> We did it before Deep Learning existed. If we had to do it again today from scratch, I think we'd use an approach similar to yours. My comment about VGG was based on experience with VGG vs AlexNet in other projects.

</comment></comment></comment><comment><USER4> Very cool stuff! We have a lot of internal tools for automatically detecting clouds at Orbital Insight as clouds present a large challenge across many types of satellite resolutions and bands. Glad to see more people are turning towards deep learning for satellite imagery.

Curious to hear how long the pipeline takes to run on a single image? Also, have you thought about running the pipeline in a fully convolutional manner, reducing the need for proposal regions?

<comment><USER5> Tacking on a shameless recruiting plug: if you're interesting in computer vision, deep learning, and/or satellite imagery, Orbital Insight is hiring! [http://orbitalinsight.com/jobs/machine_vision.html](http://orbitalinsight.com/jobs/machine_vision.html)

<comment><USER3> [Cloudless developer here]

Hi Boris! It's Brad from Dropbox :)

Responding to the parent comment, in terms of running time, the primary bottleneck is the RCNN localization portion; that takes about a minute and a half on my laptop to process a single image. In the Future Work section of the blog post I talk about collapsing the entire detection and localization pipeline into a single deconvolution network that directly takes in raw images and outputs image masks. The hope is that this runs much faster at inference time.

</comment></comment></comment><comment><USER6> Nice, but couldn't this be easier done with heuristics?

<comment><USER3> [Cloudless developer here]

It can certainly be done with hand rolled heuristics pipelines. However, one of the trends in machine learning is what is known as end to end learning - having your machine learning model automatically discover what these heuristics are going from raw input to final output. This approach now dominates in computer vision and speech understanding, replacing previously complicated hand rolled feature pipelines. It's worth attempting it on satelittle imagery as it seems the same approach should be valid there too.

Best, Brad Neuberg

</comment></comment><comment><USER7> Interesting project. Question: do the the authors have any background in meteorology? The satellite meteorology community maybe interested in this. I am at AMS this week in NOLA where there will be various talks on machine learning applied to meteorology[1]. There have been advancements in this area from groups who possess no domain knowledge and simply approach the problem from the big data side.

[1] [https://ams.confex.com/ams/96Annual/webprogram/start.html#sr...](https://ams.confex.com/ams/96Annual/webprogram/start.html#srch=words%7CMachine%20learning%7Cmethod%7Cand%7Cpge%7C1)

<comment><USER3> [Cloudless developer here]

Our backgrounds are more in machine learning and computer science than metereorology, so that aspect was new to us. As you mention we were mostly approaching the problem from having more data and tools like neural networks to throw at the problem.

Best, Brad Neuberg

</comment></comment><comment><USER3> FYI a technical article with a full write up on Cloudless is here: [http://codinginparadise.org/ebooks/html/blog/introducing_clo...](http://codinginparadise.org/ebooks/html/blog/introducing_cloudless.html)

</comment><comment><USER8> I'm wondering if a similar approach be used to detect oil spills in the ocean. What would be the challenges ?

<comment><USER3> The primary challenge is collecting enough training data to teach the neural network.

</comment></comment><comment><USER9> Landsat data has a field which gives cloud cover percent for the image. Do you know how that derive that number?

<comment><USER3> [Cloudless developer here]

I believe the Landsat cover percent field is generated by humans and historical information, but I'm not completely sure.</comment></comment>


Henry Kissinger, Eric Schmidt, and Daniel Huttenlocher on AI - <AUTHOR> https://www.theatlantic.com/magazine/archive/2019/08/henry-kissinger-the-metamorphosis-ai/592771/ <comment><USER2> Why are Eric Schmidt and Daniel Huttenlocher collaborating on articles with an infamous war criminal?

<comment><USER3> Who also has nothing of value to say about AI, for chrissakes.

<comment><USER4> "Ex-Theranos board member's thoughts on AI" sounds like something very useful to read.

/s</comment></comment></comment>


The RedMonk Programming Language Rankings: January 2018 - <AUTHOR> https://redmonk.com/sogrady/2018/03/07/language-rankings-1-18/ <comment><USER2> The Redmonk methodology of looking at stack overflow and github seems to be far superior to the TIOBE search engine approach. There is a real story in the moves on this index: the rise of Swift and Kotlin, the stagnation of go and scala.

<comment><USER3> The Go stagnation is surprising. Is it because of its simpler syntax and hence less SO questions? I'm seeing an opposite trend on the job market, Go is growing fast.

<comment><AUTHOR> Your hypothesis seems confirmed by the fact Go ranking decreases on the StackOverflow axis, but not on the GitHub axis.

</comment></comment></comment><comment><USER4> Seems clear to me that Scala's decline is exactly due to the rise of Kotlin. Whatever interest I once had in Scala has evaporated now that Kotlin has arrived.</comment>


Google Morocco hacked - <AUTHOR> http://google.co.ma/ the url is http://google.co.ma <comment><USER2> I don't see it...</comment>


Fist-sized 11M-to-1 gearbox - <AUTHOR> http://makezine.com/2015/07/08/bet-cant-find-use-11-million-1-gearbox/

<comment><USER2> The Space Needle's spinning top level is powered by a 1.5hp motor[1] at a gear ratio of 360,000:1 [2]. It makes one complete rotation every 47 minutes.

[1] [https://en.wikipedia.org/wiki/Space_Needle](https://en.wikipedia.org/wiki/Space_Needle)

[2] [https://books.google.co.uk/books?id=Jox4CAAAQBAJ&pg=PT262&lp...](https://books.google.co.uk/books?id=Jox4CAAAQBAJ&pg=PT262&lpg=PT262&dq=space+needle+gear+ratio&source=bl&ots=nzwsgU5HSu&sig=UTGSr7mBcaSWfjWJpXm8qjJ_Utc&hl=en&sa=X&ei=DGKeVdbGKMvn- QGZxquABQ&ved=0CC4Q6AEwAg#v=onepage&q=space%20needle%20gear%20ratio&f=false)

<comment><USER3> I can't find any diagrams explaining the mechanics of the restaurant (or even exactly what rotates); which upsets me. -Can someone provide more information/pictures? Even with amazing balance I don't understand how there isn't massive friction caused by whatever it's running on...

Nearly everything says it's a single 1.5hp engine (upgraded from 1hp), however there's a case study by Graybar who did a retrofit in 2013 [0] which makes it very clear that there is (and was) actually _two_ motors, both in play. -once again, if anyone has more information? I'm massively intrigued.

"The major problem was that the two existing drives were fighting to share the load – one was lagging and the other leading. The two gear boxes were constantly adjusting according to inputs from the motors, which caused both the noise and roughness during the rotation. The team determined that the best solution was to upsize the motors, drop motor revolutions per minute (RPM) and reduce the reduction ratio with the new gearboxes. So they recommended Schneider Electric drives as well as various automation and control products to the Space Needle engineering staff. The new motors were equipped with encoders feeding the drives in a master/slave configuration. Along with this, all new controls were installed, including a wireless control system. Schneider Electric also provided engineering and software support, both at the integrator and jobsite facilities."

>>> edit: I'm wondering what wattage this/these 1.5hp motors are; the Falkirk Wheel is a rotating canal lock up in scotland. It manages to simultaneously lift/lower two canal boats + water 35 meters for only 1.5kWh of energy (and has a pleasing gear system) [1] [2]

[0] [http://www.graybar.com/documents/graybar-keeps-tables- turnin...](http://www.graybar.com/documents/graybar-keeps-tables-turning-atop- space-needle)

[1] [https://en.wikipedia.org/wiki/Falkirk_Wheel](https://en.wikipedia.org/wiki/Falkirk_Wheel)

[2] [https://www.youtube.com/watch?v=n61KUGDWz2A](https://www.youtube.com/watch?v=n61KUGDWz2A)

<comment><USER4> The restaurant floor, a ring around the core, rotates. The observation deck, exterior and center do not.

</comment></comment></comment><comment><USER5> I highly recommend going through Oskar's other puzzles and contraptions which includes tons of very very strange cubes, puzzle rings and other oddities:

[https://www.youtube.com/user/OskarPuzzle](https://www.youtube.com/user/OskarPuzzle)

[http://oskarvandeventer.nl/hanayama.html](http://oskarvandeventer.nl/hanayama.html)

He also has done a ton of collaborations with Bram Cohen of Bittorent fame like this one:

[https://www.youtube.com/watch?v=RTcGCqz4ajs](https://www.youtube.com/watch?v=RTcGCqz4ajs)

He's definitely one of those guys who just can't stop creating puzzles and new ways of thinking about problems.

</comment><comment><USER6> The application is obvious: DIY "Machine with Concrete" ([http://makezine.com/2012/04/25/arthur-gansons-machine- with-c...](http://makezine.com/2012/04/25/arthur-gansons-machine-with- concrete/)) kits. I'm sure Arthur Ganson won't mind.

<comment><USER7> Really neat, thank you!

</comment></comment><comment><USER8> This is not too different from a harmonic drive. In fact it's basically a single-planet epicyclic drive inside a harmonic drive. Kind of nice but I don't know if it counts as a new type of gearbox.

[https://en.wikipedia.org/wiki/Harmonic_drive](https://en.wikipedia.org/wiki/Harmonic_drive)

<comment><USER9> Well, harmonic drives are cycloid drives that use elasticity rather than eccentricity to do the same task, so let's focus on cycloid drives.

It's not quite the same your typical cycloid drive, but it has a strong relationship. Cycloid gears are about having an inner circle of radius A rotating within an outer circle of radius B by putting the center of A's circle on its own circle of radius C = B - A.

If C is small, then a fast rotation of C produces a slow off-center rotation of B relative to A. Since it's off-center, usually a bunch of holes (theoretically also of radius C, I think?) are drilled in B and filled with "output rollers" which connect to one single shaft which is on-center relative to C. Thus C connects on-center to this asymmetric B, which connects to an on- center output shaft that otherwise rotates as B does.

In his case, these holes don't exist and the rotation is never on-center. But you can use the same mechanism to convert his amateur cycloidal drive to one that has an on-center rotation of the input shaft.

Now normally in a cycloidal drive, A is regarded as fixed, while C is rotating, and B is still. In this case his C is totally implicit, his B is rotating, and he is at _two different_ A's which rotate relative to each other. There are therefore presumably two different Cs, too.

It's hard to really isolate the exact mechanism in terms of connected cycloid drives. It is _not_ as simple as fixing C and watching a _single_ cycloidal drive's A rotate as a response to a rotating B, because that would have the reverse mechanical advantage. It's also not obviously "two cycloidal drives connected together by C", which would have a mechanical advantage near 1.

So I'm not sure what it is, but I don't think you can just say "oh, it's a harmonic drive."

</comment></comment><comment><USER10> This "extract the difference of speeds between two parts" method is quite common to get extremely high reduction in a small amount of space; this is a ~70:1 single-stage gearbox found in a rearview mirror positioner, and it only has 6 parts:

[https://en.wikipedia.org/wiki/File:Rearview_Mirror_Epicyclic...](https://en.wikipedia.org/wiki/File:Rearview_Mirror_Epicyclic_Gears.jpg)

Put 4 of those in series and you'll get 24M:1.

</comment><comment><USER11> > We live in a world where an idea that does something that has never been > done before can be built at home and shared without cost [...], all without > it having any use or any place in the market. Outside of art, that is > something we did not have a few years ago.

I do not agree with this idea. Many inventions have been driven by curiosity. People playing with magnets or 8 bits computers were not trying to solve any market problem. Even physics were developed by simple people sharing curious "unuseful" experiments for centuries.

<comment><USER12> If anything, individuals seem to have stopped inventing/investigating. It used to be that persons of means would use their means in the pursuit of some expansion of their knowledge. Now it's in pursuit of more means.

<comment><USER13> This is a common historical fallacy. Like "It used to be that Greeks would sit around inventing geometry, philosophy, and democracy. Now they just ruin banks."

There were always both kinds of people, and the inventors who are driven by the love of science and learning have always been a minority. It's just that the people who only care about personal wealth rarely make it into history books, whereas the iconoclastic scientists frequently do. And the same is true today.

<comment><USER14> "It's just that the people who only care about personal wealth rarely make it into history books, whereas the iconoclastic scientists frequently do."

Arguably even this isn't true - Many people know the name of, say, Archimedes and Newton, but I doubt it's more than the people who know Julius Caesar and Genghis Khan. Might be close though.

<comment><USER13> What I'm trying to say is, what percentage of people can name a couple of great thinkers from the classical era? Now compare that to the percentage of people who can name a wealthy merchant or banker from the same period.

</comment></comment></comment></comment></comment><comment><USER15> The article mentions slippage, grinding, play, noise and vibration. These are generally undesirable in machinery. Slippage and grinding suggest significant problems with wear and durability. That would limit the lifespan of the gearbox.

It's still pretty cool and could be very useful. That doesn't mean there aren't useful applications. It just means there are design tradeoffs.

<comment><USER16> It looks like a pretty rudimentary prototype. Many of those issues are addressed with better manufacturing tolerances, different materials, and tooth profiles. I'm not sure those features are inherent limitations as much as drawbacks to the prototype implementation.

</comment></comment><comment><USER17> > _Headed in a different direction, Van Deventer has a new type of gear he > calls "grinder gears" that comprise an inner gear with one fewer tooth than > the outer gear, causing it to wobble its way through the rotation. For the > engineers, it's a variation of a cycloidal drive._

Oh, he reinvented a Gerotor.

> _A gerotor unit consists of an inner and outer rotor. The inner rotor has N > teeth, and the outer rotor has N+1 teeth. The inner rotor is located off- > center and both rotors rotate._ > [https://en.m.wikipedia.org/wiki/Gerotor](https://en.m.wikipedia.org/wiki/Gerotor)

</comment><comment><USER18> It's not completely something new [https://www.youtube.com/watch?v=MBWkibie_5I](https://www.youtube.com/watch?v=MBWkibie_5I)

</comment><comment><USER19> The article points out issues with this exact implementation at an 11M:1 gear ratio but begs the question whether a less extreme ratio using "grinder" gears has any application or not.

Regardless, the conclusion about new innovations at the end of the article was exciting/encouraging to read.

</comment><comment><USER20> I am most concerned about the efficiency of a design like this. People usually look for a gear reduction to increase torque, but an inefficient gearbox can make the output both slower _and lower torque_ which is rarely desirable.

The wobbling input shaft would also be tough to work around.

</comment><comment><USER21> Perhaps not with this ratio, but something like this with a quartz movement, with the right ratios should be able to advance a "day of year hand" around the face of a clock.

If you wanted to get really fancy, advance a DoY-hand for Venus, Mars, Jupiter, as well as the Earth's.

</comment><comment><USER22> I want to see the inverse.

Eleven million spins with one rotation of the shaft.

<comment><USER16> Friction will prevent that, similar to the self-locking behavior of a worm gear. Even if you could get it started, it would take as much energy to spin the output shaft once as it takes to spin the input shaft 11 million times. If you tried to quickly spin the output shaft, the forces exerted on the gears would shred the materials almost instantly.

<comment><USER23> It would be fun to calculate the power input required for that. I suspect it would be in the range of megawatts or so - instantly vaporizing the gearbox (assuming you could somehow push that power into it before you destroy it mechanically).

</comment></comment></comment><comment><USER24> The mechanism is reminiscent of the one in the Newbould Indexer: [http://www.imperialnewbould.com/the-newbould- indexer.html](http://www.imperialnewbould.com/the-newbould-indexer.html)

This discussion has a link to RJ Newbould describing how he invented the indexer: [http://www.chiefdelphi.com/forums/archive/index.php/t-68265....](http://www.chiefdelphi.com/forums/archive/index.php/t-68265.html) It's a really interesting explanation for us mechanism geeks :-)

</comment><comment><USER25>
        Gune: [holding up a small device] Does this look familiar? Do you know what it is?
              Neither do I. I made it last night in my sleep.
              Apparently I used Gindrogac. Highly unstable.
        Preed: Gune...
        Gune: I put at button on it. Yes. I wish to press it,
              but I'm not sure what will happen if I do.

[http://www.imdb.com/title/tt0120913/](http://www.imdb.com/title/tt0120913/)

Seriously, this is a cool device. And I have no idea what I could use it for...

</comment><comment><USER26> I wonder what's the highest torque it can sustain without breaking. That will in turn severely limit applications because with that demultiplocation little torque will be huge at the other end.

</comment><comment><USER27> Reminds me of a fun trick that was popular when I was in undergraduate mechanical engineering: A gear train that has one end spinning, powered by a small DC motor, and one end bolted/welded/glued/otherwise fixed solidly to a wall.

Increase the ratio enough and you can have an output shaft that will take years to go through even a fraction of a revolution ;)

<comment><USER28> There is one by Arthur Ganson in the MIT museum[1]. It's part of a great exhibit of fun/quirky machines and there's an interesting video about it on youtube[2].

[1] [https://www.youtube.com/watch?v=5q-BH- tvxEg](https://www.youtube.com/watch?v=5q-BH-tvxEg) [2] [https://www.youtube.com/watch?v=2Rov_Lriqvk](https://www.youtube.com/watch?v=2Rov_Lriqvk)

</comment></comment><comment><USER29> Will this also work as a 1 to 11M gearbox? If so it might allow a strong force (e.g. the weight of a large body of water) to spin a small electric generator. That will allow small scale hydroelectric storage for renewable sources.

If not it can probably still find some applications for turning something like weak wind power into something that can create great pressure.

<comment><USER30> I know nothing about this, but I would imagine that this gearbox would need to be made out of some other-worldly material in order to cope with the force necessary to drive it in reverse

<comment><USER31> I'm pretty sure it's already potentially self destructive if there is any snag in the output.

</comment></comment></comment><comment><USER32> Looks like a bunch of harmonic drive gears in a row. Every industrial robot contains a couple of these.

</comment><comment><USER33> What you are describing is called "backdriving" the gearbox. Generally speaking, gear trains with high reduction ratios don't like to be backdriven. Small steel gear trains with ratios in the 1000:1 range can destroy themselves when back driven.

</comment><comment><USER34> Could it be used for high precision movements? For example a stepper motor with very small and large movements? I know it's mentioned in the article.. but if it could be done then one could maybe create a CNC for DIY CMOS or something.

</comment><comment><USER35> Here's a planetary drive using roughly the same concept. This is 64:1 per stage.

[https://www.youtube.com/watch?v=P-Obt-9tZVo](https://www.youtube.com/watch?v=P-Obt-9tZVo)

</comment><comment><USER36> Just a 3D printed gearbox. For me this is rather a promotional article than something really interesting. We've been able to print these kind of gears for years with reprap or reprap-like 3d printers.

</comment><comment><USER37> If it had enough torque (which seems to be a problem given the plastic nature) I could see it breaking loose rusted or stubborn bolts. Maybe? In a scenario like that you wouldn't really care about precision or sound. Though 11 million turns still seems like a lot of cranking... maybe if it had a 9v attachment it could be a portable bolt breaker. Feels like a stretch though, would be fun to play with.

Though now that I think about it the holder of the bolt breaker would probably start slowly turning before the bolt does... weeeee

<comment><USER38> The problem with rusted or stubborn bolts I've encountered is the mechanical friction on the threads usually greatly exceeds the shear force (??) that the bolt can tolerate. I've snapped a head off more than once. That's a real bummer.

</comment></comment><comment><USER39> I feel like it could be used to construct mechanical calendars.

<comment><USER40> Precision could be an issue according to the faq.

</comment></comment><comment><USER41> I know the answer..think Tesla..but instead of a small auto a big truck or better yet a big ship...

both require a rethinking of the transmission to transfer power from the engine to the wheels or propeller in order to get bigger torque

this gear device solves that particular problem

</comment><comment><USER42> Because of the non-back-drivability, I would use this for making winches.

</comment><comment><USER43> Its sometimes nice to take a break from software/digital engineering and build stuff in the real physical world. Feels like a vacation for my brain almost.

</comment><comment><USER44> Would be good for a telescope mount, maybe.

</comment><comment><USER45> Why wouldn't one just use three nested cycloidal gears to achieve the same result?

</comment><comment><USER46> Why they include an animated gif of someone turning _another_ gearbox with a far lower ratio puzzles me.

But I'm going to go with "yes, this is useless, unless remade with much better materials". The current version is imprecise, high-friction, snd can't even survive one rotation of the output.

<comment><USER46> Huh. Was someone under the impression that the GIF _was_ of the gearbox in question, or did they not RTFA enough to realize I was simply agreeing with the inventor for the same reasons he enumerates?

<comment><USER47> That is the gearbox. The output shaft is the red one.

<comment><USER46> You're right, sorry. I hadn't watched the second video.</comment></comment></comment></comment>


Dot-Com IPO Insanity Returns With Coupons.com - <AUTHOR> http://www.bloombergview.com/articles/2014-03-07/dot-com-ipo-insanity-returns-with-coupons-com

<comment><USER2> I can agree that the market is over-valuing coupons.com, but not with the overall emphasis on past profits in IPOs. "But they're losing money and hugely over-valued!" is a sentiment I hear a lot from traders and observers who deal in established companies, but it may or may not apply to IPOs and new companies.

Coupons.com has been around for a long time (1998), and if it hasn't figured out a way to be profitable in 15 years I don't think a cash infusion is going to help. I don't see any evidence of a new product or service or a new revenue stream. In fact I'd bet against coupons.com growing as users become weary (for the non-technical) and wary (places like HN) of additional browser addons.

COUP aside, sometimes it's wise to ignore profits in an IPO. Emerging markets, new technologies, and early-stage high-growth startups are good examples.

For example, Tesla lost over 55 million the year before its IPO.[1] Some said the shares were too high, but it paid off[2] for those who saw the potential. Musk pointed this out himself:

 _" A lot of people were puzzled about why we were going public without profits," Musk told reporters outside the Nasdaq building in Times Square. "The reason we are not profitable today is because we are in the midst of expanding with the Model S."_

New product, new market, growing company. Check. Proven management team with realistic expectations and a strong proof-of-concept? Check.

In Tesla's case it makes sense to ignore past losses and bet on the long play. While coupons.com could become profitable, I'll be shocked if the premium paid on this IPO pays off.

[1] [http://www.wired.com/autopia/2010/06/tesla-ipo- raises-226-1-...](http://www.wired.com/autopia/2010/06/tesla-ipo- raises-226-1-million/) [2] [https://www.google.com/finance?q=tesla](https://www.google.com/finance?q=tesla)

<comment><USER3> I really don't think that it's fair to compare Tesla with Coupons.com. Tesla has net assets of $2.4 billion, with IP that's worth a considerable amount. This is evidence to show that it may be worth investing. What does coupons.com have? A failing 16 year old business that hasn't once turned a profit?

Edit: Just noticed you said COUP aside. I agree with you – the comparisons from tech or unprofitable IPOs don't add up.

</comment></comment><comment><USER4> I agree that COUP is overvalued, but I do not like this superficial stock analysis. A lot more goes into evaluating growth stocks. One has to consider the trajectory the company is going on, how likely it is it will continue on this trajectory, when things will plateau, etc. You can't just say "its not making money therefore it is a sell." Well you can, but you won't be a very good growth investor. You might be one of the many people that refused to buy google at $100 because their P/E was insanely high.

Looking at COUP's S1 I can say a couple of nice things about them. They are showing good topline growth. Their gross margins are expanding. Their net margins (while negative) are improving very fast. From 2012 to 2013 they grew their revenues by almost 50% while they actually reduced their operating expenses. But most importantly, their revenue growth is accelerating.

If they continue posting higher and higher revenue growth and expanding growth margins, they may start gushing money in a couple of years.

As I said they are not for me. I am not sure they can continue high revenue growth for long because they do not seem to have a good lasting competitive advantage. But I can see how someone may be convinced to buy them.

</comment><comment><USER5> My take in bubbleness is people moving to California for the express reason of working in a startup. If you're doing that because you're an entrepreneurial type and you want to learn about the ins and outs of running a company and your not a stranger to hard work, rapidly changing priorities, and the journey is its own reward, great. But if you're doing that because "startups are cool" and "Man, you get in early and suddenly _bam!_ your like a zillionaire even if you're the Janitor, dude, sign me up!" Well you're chasing a bubble not a career :-). The saddest part for me in the late 90's was the influx of business majors who were going to 'show up how its done' as opposed to problem solvers and team builders.

That said, I'm feeling like there are more and more people in the bay area at least for the wrong reasons. And I for one, having lived through the first bubble, have been milking it rather than going all in (bought some FB when it got down to $18 and sold it once it crossed $36. bought some Tesla, sold it when it doubled) took the money out and put it in more diversified things (like index funds). Its boring, you don't make the 'big score' but when the music stops, and the music always stops, _this time_ it won't all evaporate. At least that is what I keep telling myself :-)

<comment><USER6> > _The saddest part for me in the late 90 's was the influx of business majors > who were going to 'show up how its done' as opposed to problem solvers and > team builders._

Funny, the saddest part for me, both in the late 90s and today, are the "Tech Stars" who are living high on the hog on other people's money, with some pipe dream of getting bought out and no plan to run a real, viable, sustainable business. Their businesses implode, they get "rich" (through money and contacts) and move on to the next project.

Laugh all you want at the MBAs, but I can assure you that they, at the very least, understand that the purpose of a business is to create value for customers and generate a return for stakeholders. I think "Silicon Valley" could have used a bit more of that sort of thinking then, as perhaps more so today.

<comment><USER5> I think that 'ninja/rockstar/ego-driven' technologists are sad in their own way. Somewhat differently than unseasoned MBAs though. There was a joke that was old even when I moved to the Bay Area in the 80's that you knew you were a 'successful' engineer when companies issued a press release that you had joined them, but they had no idea what you were going to do for them. And like most jokes there was a painful truth that for some people it really is all about them.

That said, I find it is also easy for me to fall into the trap of looking primarily at the excesses and sillyness and overlooking the cool things that get built. One of my long time friends is working at Intuitive Surgical and they are doing some really innovative and cool stuff that is not at all frivolous.

</comment></comment></comment><comment><USER7> "But like so many other companies in these golden times, Coupons.com simply told investors to exclude about $13 million of normal everyday expenses and, abracadabra, it claims to be profitable on a nonstandard, cockamamie "adjusted Ebitda" basis. It's all part of the show."

My impression is that Groupon made up their own mumbo jumbo financial metrics, but that adjusted EBITDA is a pretty standard financial metric.

<comment><USER8> _adjusted EBITDA is a pretty standard financial metric_

No... EBITDA is already "adjusted earnings". Adjusted EBITDA is "Adjusted, Adjusted" earnings. Or more correctedly <opportunistically> Adjusted Earnings.

<comment><USER9> EBITDA is already opportunistically adjusted, it's just that people more or less agree which "bad" numbers get excluded.

I understand the argument though. EBITDA is somewhat closer to $income - $cost. Whereas actual earnings involve tax, tax loopholes, exchange rates, and loads of other crap.

</comment></comment></comment><comment><USER10> The adjusted EBITDA the author talks about is on page 12 of the S-1 filing[0]. The largest items that take the $11M net loss to positive EBITDA is $7M of depreciation & amortization and $5M of stock based compensation.

[0][http://www.sec.gov/Archives/edgar/data/1115128/0001193125140...](http://www.sec.gov/Archives/edgar/data/1115128/000119312514066562/d612699ds1a.htm)

</comment><comment><USER11> >>> The worst thing you could do is have a denominator in your price-to- earnings ratio that's greater than zero, because then your ratio would be positive, assuming your stock hasn't gone to zero yet.

I've always wondered why folks don't use earnings-to-price ratio instead, which goes smoothly through zero instead of behaving, well, hyperbolically.

</comment><comment><USER12> If anyone wants to read the filings for themselves:

Coupons.com [http://www.wellreadinvestor.com/companies/63241](http://www.wellreadinvestor.com/companies/63241)

Groupon [http://www.wellreadinvestor.com/companies/10946](http://www.wellreadinvestor.com/companies/10946)

<comment><USER13> You should not compare Coupons.com to Groupon. Different businesses. Groupon sells deals - you have to put money upfront i.e. commit to a discount. Coupons.com prints money in the form of %/$ off discounts. No need to commit any money even after you acquire a coupon from Coupons.com.

</comment></comment><comment><USER14> When a company like this goes public, do they have to include in their filing specifically which channels are driving revenue? For example, do they mention what % of Coupons.com revenue is from SEO vs. SEM vs. Email Marketing vs. Direct traffic - or does Wall Street just understand all that as one big "Internet" channel?

<comment><USER15> Here is a hint: [http://www.similarweb.com/website/coupons.com](http://www.similarweb.com/website/coupons.com)

The question is, which one is a bigger stinker, coupons.com or retailmenot? Both make a significant portion of their revenue ranking organically on Google for other big companies' name. What happens when this traffic shrinks or is lost?

As an investor I am very concerned when a company publicly publishes that they make tens of millions or hundreds of millions of dollars off of a free stream of traffic from Google. Companies can establish a brand from that position, but its ultimately their financials which determine their long term survival. Zynga offers an alternative example, grew very fast due to a never to be repeated level of free visibility on Facebook's news feeds. Multi-billion dollar mobile gaming companies are in very similar positions today.

I'm not saying these companies or websites are worthless, but the valuations are insane for the risk they entail. High valuations make companies spend more and borrow more than they should.

Does a company own their user base? That is a pretty good indicator of long term viability. Ironically, Microsoft of the 90s looks like a fairly friendly neighbor in comparison to the "platforms" software businesses are built upon today.

<comment><USER16> Correct me if I'm wrong, but Retailmenot's business model is drawing in people seeking discount codes and then tags their affiliate codes when the user clicks through to site to actually make a purchase.

Coupon.com's business model is to be the online distributor of manufacturer and store coupons. I'd have to think Coupon.com's revenue comes more from manufactures and stores licensing / paying for inclusion on the Coupon.com website than from affiliate marketing.

Retailmenot is getting 73% of its total traffic from search and Coupons.com is less than half of that at 35%.

I think Coupons.com also has a more engaged audien than Retailmenot and a large network of coupon bloggers promoting the product and participating as affiliates.

<comment><USER15> Yes, I agree. The flip side is that retailmenot is profitable while coupons.com is not. Neither would be in good shape if they lost their free traffic. Can coupons.com still support their affiliate/referral payments if they lost the x% of revenue they don't have to pay much for?

</comment></comment></comment></comment><comment><USER17> Is it coincidence that their stock ticker is COUP? [http://dictionary.reference.com/browse/coup](http://dictionary.reference.com/browse/coup)

</comment><comment><USER18> Is this any more insane that $CRM? Quarter after quarter of losses, and the market cap has been all over the place.</comment>


Ask HN: Best hardware for Ubuntu? - <AUTHOR>

I'm getting into Ubuntu, and read on several forums that OSX Lion borked any chances of dual booting on a MacBook. What are my best bets for hardware (preferably laptops)? <comment><AUTHOR> Thanks for all the suggestions guys. I'm having some fun trying out Ubuntu on VirtualBox in Lion. I actually made another user account and running it full screen is pretty seamless. I still want to check out the Lenovo hardware based on the answers so far. Thanks everyone!

</comment><comment><USER2> If you want to strap a monitor to your laptop don't go with Dell, (I've had several problems with the Dell XPS and Ubuntu including a white screen of death), Ubuntu probably won't recognize the driver.

</comment><comment><USER3> I've had a good experience with Ubuntu on one of Dell's Vostro laptops. Vostros are part of Dell's small business offerings, but you don't have to actually run a business to buy or use them.

</comment><comment><USER4> I've had good experiences with Thinkpads, Ubuntu has their own list:

<http://www.ubuntu.com/certification/desktop/>

</comment><comment><USER5> Anything Lenovo is generally deemed to have a fairly decent build quality, along with some of the best Linux compatibility amongst laptop manufacturers.

</comment><comment><USER6> I've been using Thinkpad (T series) on Ubuntu for 3 years now. Faced absolutely no problem whatsoever. Also like their keyboards.

</comment><comment><USER7> I run Ubuntu 12.04 on my Macbook Air and it works great. I love it.

</comment><comment><USER8> I would say using a VM with ubuntu isnt so bad

</comment><comment><USER9> I have Ubuntu 12 running on a Toshiba laptop. Runs fine.

Toshiba's keyboards kind of suck now but otherwise they are pretty solid.

</comment><comment><USER10> I setup Ubuntu 11 along with Windows 7 on my Lenovo laptop and it has been working beautifully so far.</comment>


Building AI Trading Systems - <AUTHOR> https://dennybritz.com/blog/ai-trading/ <comment><USER3> I tried doing some forecasting with various neural network models after assembling what I thought was a good amount of forex data. The neural net (I tried various architectures) couldn't do any better than chance. After playing around with it and trying to double-check everything, that was as far as I could get. This puts me ahead of most traders, since most of them lose money, then quit.

This makes me wonder what kind of trading systems can actually have any kind of edge, since some kind of autoregressive time series forecasting system seems pretty unreliable.

On a more general note, how do you move beyond it being gambling? Just because a system backtests well doesn't mean a phenomenon will continue to happen, especially if your system will significantly impact the market you're in. If you make a trend-following system, every time you trade, you're gambling that the trend is more likely to continue than not. If you're right, you'll come out ahead over many trades. If you don't have enough capital to withstand drawdown the way most beginners don't, you won't be able to last long enough for whatever phenomenon you've found to average out.

It takes a lot of time, effort and risk to do all this, so, this is a long- winded way of saying I don't think it's for me. If you build a SaaS product and it fails, at least you can talk about what you learned from building it and use that in future endeavors. If you lose money trading because your algorithm doesn't work, what do you learn from that besides that your algorithm doesn't work?

<comment><USER4> You need more data to input besides just the price time-series. Successful human traders balance and synthesize a myriad of data sources to make decisions.

I depend on an in-depth understanding of human psychology as one of my data sources. You can't turn something like that into data and input to a model. It is something learned through life experience and study.

<comment><USER5> +1 Any trading strategy based only on price is fool's errand. The information that impacts price need to be included in the trading strategy. A lot of short term price movement is news driven, thus unstructured text processing of news, social media, relevant documents will be a key component of such trading strategies.

I am not that familiar with forex market compared to equity market. But I expect forex to be impacted by changes in political and economic situational news of host countries of relevant currency pairs. All these need to be coded into forex trading strategies.

If trading based on just price was so simple , everybody would be doing it successfully.

<comment><USER6> No successful strategy ever has been based on price. Price isn't stationary so you can't do anything with it. You need to be looking at the log returns. Price is completely irrelevant, at least for equities.

<comment><USER7> Sorry, but that is wrong. All I use is price and time. See Elliot Wave Theory. Most indicators are perfectly correlated with price meaning unless you are a HFT you can't trade fast enough to act on them.

<comment><USER6> Elliot wave theory is quackery. Price is not suitable for any statistical analysis.

<comment><USER7> It has changed and it is just observations of competing waves of pessimism and optimism and the patterns they demonstrate. I'll put a model trained on TQQQ and SQQQ price and time data only. I will bet you 5k mine will beat yours using whatever inputs you choose over any reasonable time you specify.

</comment></comment></comment></comment></comment></comment></comment><comment><USER8> Just a reminder: nobody ever wrote about their super successful trading strategy. Its just never happened. If you have the wherewithal to research and build a trading system that works, then you're smart enough to know that the moment you reveal your edge to the world - it disappears. Even if you dont discuss the innards of your strategy, but you talk about your process or the system youre strategy is built on, you've revealed too much.

<comment><USER9> This is a simplified version of the truth. There is a lot of information that you can safely share because the number of people that will know where to look for it, know how to implement it, what to even do with it, how not to make any one of 100possible stupid mistakes while implementing it - is very low.

Example in point: Warren Buffet. All of his process is public knowledge, he constantly writes and talks about it. And yet somehow it didn't make him lose his edge.

<comment><USER10> Not exactly. We know the broad strokes. He figures a price for a company by estimating their lifetime earnings and then factoring in the time value of money. He's talked about a mental checklist he goes through when looking at quarterly reports, but he never talks about the exact details of this process. Whether he's lost his edge, that's debatable too. The time since he's beaten the S&P is now entering into the long-term.

</comment></comment></comment><comment><USER11> I find most of this article to be "successful people can't explain why they are successful so they say a bunch of arbitrary things they've noticed".

He found success pursuing relative advantages, infrastructure advantages, and building custom tools from scratch.

But absolute vs relative advantages, plumbing together canned solutions vs building your own from scratch, infrastructure-level advantages vs decision making advantages...all of those contrasts exist in other businesses everywhere. None of those are specific to trading.

> "in my experience, nothing beats learning by doing or finding a mentor"

This hits the nail on the head.

The best way to become a profitable trader is with a mentor, but it's nearly entirely luck. You drive an Uber or tend bar and happen to make friends with someone successful who is willing to guide you. Trying to seek out a mentor online is nearly impossible, as everyone who is findable and willing is almost certainly a better marketer than trader.

The other way to become a profitable trader is to start trading with real money. It's amazing how quickly one can learn how to mend a boat, when the boat starts sinking.

</comment><comment><USER12> readers may also be interested in Benter's paper "Computer Based Horse Race Handicapping and Wagering Systems: A Report" \-- [https://www.gwern.net/docs/statistics/decision/1994-benter.p...](https://www.gwern.net/docs/statistics/decision/1994-benter.pdf)

> This paper examines the elements necessary for a practical and successful > computerized horse race handicapping and wagering system. Data requirements, > handicapping model development, wagering strategy, and feasibility are > addressed. A logit-based technique and a corresponding heuristic measure of > improvement are described for combining a fundamental handicapping model > with the public's implied probability estimates. The author reports > significant positive results in five years of actual implementation of such > a system. This result can be interpreted as evidence of inefficiency in > pari-mutuel racetrack wagering. This paper aims to emphasize those aspects > of computer handicapping which the author has found most important in > practical application of such a system

Arguably the paper describes the state of the art from three decades ago, applied to betting on Hong Kong horse races, not market price movements.

<comment><USER13> Yeah this is a great paper on the subject. Although horse betting is different than financial markets due to the parimutuel system.

<comment><USER14> Does that mean you have to find a greater edge to cover the house edge?

</comment></comment></comment><comment><USER15> Writing ai trading systems is the coding I do for fun since 2012. I'm a little under break even so far but I keep at it because find it so interesting. Since I started every single week I have learned a new way of thinking about a problem I encountered or a new approach to problems that still stand in my way.

Questions like, how do you choose a stoploss? Well you can pick it statistically based on history or you can use a supervised label. You can even use stock A calculated stoploss to pick the stoploss you use on stock B because you found a condition under which those two stocks became almost identicall correlated. How do you want to pick the supervised label? You can do spectral analysis to pick the stoploss too. You can use sentiment as a stoploss, source from google news or twitter or stocktwits.

It doesn't have to be, 'well I measured the average profitable stoploss to use over the last 10 years across all stocks and that isn't working so I quit'

Things like that, you get to fit the ideas together and then test them in the real world.

There are some things I would like to share.

1\. Just because you have a good forecast doesn't translate into cash. It has to be paired with a trading strategy. This is probably why the author thinks the answer is RL, because coincidentally if you approach this problem with RL, it does the forecasting + strategy.

2\. I have measured a correlation between heavier processing(using a higher big O) and better out of sample performance.

The criticisms with the NN approach like non stationary data have obvious solutions that a 'by the book' trading approach + ml approach don't really teach beginners so they dismiss it.

It is my belief right now that there are people who are prepping data from sources like iextrading then using things like sagemaker to develop good enough forecasting and combining it with a statistics+rules based trading strategy to make living wages.

That said, I have 5k account size for my NN obsessions, and my 401k is 'by the book'.

person_of_color is totally right when he says it is a Moby Dick of programming.

<comment><USER16> It sounds like a lot of fun! I love the idea that there's one metric ($) to measure the effectiveness of your strategy/code.

Any recommendations or hints on where to get started (assuming I'm decent with python/pandas etc)?

<comment><USER15> Yes!

1\. I would start in the numerai tournament, I did this for 3 years after the first two years of me by myself on the market. It's useful because they provide ml ready data, and you can iterate very quickly. If you do not have ML experience numerai will teach you about many different types of overfitting and the many correct and incorrect ways to deal with them. An example would be some ML people always apply dropout, but when you have a small signal to begin with, dropout can dropout the signal, and then there is only noise left for the model to fit and of course it will then perform poorly. The other thing it will help with is the hopelessness that you will encounter from hitting a wall(hitting a wall is common in ML, and should be expected), the scoreboard shows individuals who have broken through that wall so you can know it is possible. I stopped participating after stabilizing in the top 20 because they change the format of the tournament every so often and I wanted my Saturdays back. You don't need to reach top 20, I hit a wall around rank 100 back when they used actual bitcoin to pay people. You just need to do well in one of the rounds where everyone else fails so you can go through the process of 'what did I do that I'm not aware of that made me succeed where everyone else failed'

2\. Read Advances in Financial Machine Learning by Marcos Lopez de Prado. This goes over the false assumptions that outsiders make, and then outlines rookie mistakes(I made many of the mistakes described in the book, then read this book when it came out). It also will break you out of the thinking that leads to typical approaches and why it is unrealistic to expect them to work.

3\. Become familiar with retail trader mistakes like overtrading, improper sizing, and emotions as well as the fact that you cannot rely upon regulating bodies to prevent fraud from occurring, they only act after it has occurred.(This is for scenarios where your models says short this stock, then you see that the stock is fraudulent but it continues to exist.) Learning blackjack probabilities + sizing helps with developing a strategy. Things like, do you want a trading system that has 60% accuracy and 10% profit each time, or one that has 45% accuracy but 200% profit each time. It's interesting because even if you have a 50% accurate 200% profit/50% loss strategy, you still need to calculate the probability of what number of losses you will see in a row that will still bankrupt you if you have the wrong size. In college for me this was covered under the Discrete Math Class.

After steps 1+2+3 I think people who have some level of control over their emotions have the right foundation to code a system. There are people that should not trade because they don't have the right personality profile.

4\. Find a way to fit the data you encounter into a DB. Early on I had to pay 100 a month to get daily csvs for stock data. I wrote code that answered questions for me from the csvs. This was wasted time, because you can write SQL to answer so many questions. Keep this DB on a separate computer from the one you do ML dev on. Because the computer that ML dev happens on inevitably gets wiped(it will happen to you).

Then for you its a matter of just leveraging python+pandas etc to code a solution that meets your criteria. There are three categories that you have to operate across, infrastructure+forecasting+trading strategy. When you see one of your models predictions become true it really is a different feeling. But to ease my conscience I should warn you, if you are the curious type and you try this once, you will always be curious about it.

For timeseries data im currently using iextrading even though it has downsides(they only have data for trades that route through their exchange). I used to use kibot, alphavantage,scrape yahoo, download stock data csvs from ebay,and save etrade realtime quotes. For placing trades I am currently using alpaca.(I've used IB,etrade,and robinhoods private api before they blocked it).

<comment><USER17> I see you posted you are at break even since 2012. Most people wipe out in 3 years so good job.

I recommend trading manually to feel and listen to the market so that you can adapt your code to it. Also, maybe you are overthinking your strategy so don't hesitate to remove parameters.

My discord is open you can join it and see my trades and look to find any insights from what I enter.

</comment></comment></comment></comment><comment><USER18> Don't do this. It's the programmers Moby Dick. You are better off self learning stats/ML skills in your free time and joining a quant fund than to try and do it yourself.

<comment><USER19> Agreed. It's a goose chase, the house always wins and even a winning system works one week and not the next.

</comment></comment><comment><USER20> I would love to try trading as a hobby with a little side money, but I would abhor a hobby that reduces to effectively buying the trader-feel-good experience, where you're essentially sponsoring incumbents as a fanboy chipping in his pocket money.

What I would require from a trading platform:

1) decentralized and permissionless 2) provably fair trading

With 'provably fair trading' I mean the protocol should be such that I can prove you are not simply held captive by an intermediary, regardless in what shape or form. It should also be fair with respect to latency.

For example consider a trading market where token X can be exchanged for token Y and vice versa. Each holder of X demands her minimum of Y per X, and each holder of Y demands his minimum of X per Y. What if everyone salty hashed their demands, and pays the market contract (proportional to how much they will actually be allowed to trade) to register their salted hash. When the round has closed, people reveal their salt and plaintext, and the incompatible trading offers get their money back (minus a usage fee perhaps). The compatible ones can have their trades go through at the rate of 'total compatible X offered' to 'total compatible Y offered' (or some variation thereof, say rewarding those that helped close the gap). In this way there is no high frequency trading, and you could have a family of such markets operating at different timescales...

</comment><comment><USER21> I've never tried the AI trading path but I imagine that you can't get huge gains with public data, unless you find a way to extract "hidden" information by processing real time news.

I wonder nevertheless if there's a sweet spot where you can build a simple AI trading algorithm and get modest earnings from it.

<comment> nv-vn I think the answer is yes & no. If you come up with a sufficiently clever strategy using public data that other people haven't thought to use it's definitely doable. For example, someone with a good understanding of meteorology would've had a significant advantage a few decades ago (though trading firms have since caught on). You wouldn't need a perfect data set if the strategy isn't being used.

In terms of strategies based purely on market data, you are definitely correct. Any publicly (freely/cheaply) available market data is low resolution, lacking the full data from any point in time, and generally based on poor approximations of the actual data (elsewhere in this thread someone mentions that IEX's data is based on trades that get routed through the IEX exchange, which obviously misses any data you could get from the markets that make up 99% of the volume, dark pools, etc.).

I think the "sweet spot" is simply coming up with a strategy that nobody else has thought about, or else executing a better-known strategy more effectively than other market participants. Both are hard, but somewhat in the realm of possibility. The problem is that many people think there's free money to be made without either of these.

</comment></comment><comment><USER22> For the last year or so I have been working on a ML-based trading system in the domain of crypto with two friends. I made more in 2 months than I used to in a year. This is after thousands of "full positions swings" and millions of trades (short and long). We are now experimenting with different classes of trading strategies to reduce risk.

We would like to find 1 or 2 more people to work on this project, we need people who can tolerate risk and skilled at data engineering: data pipelines, psql, pandas, numpy, data visualisation, setting up servers. Ideally also skilled at machine learning / deep learning and who has tried his hand at trading systems. If interested, my email is in my about info.

</comment><comment><USER23> "Actually, many months my PnL graph looked something like this: (this is generated to get a point across, but my real data looked extremely similar):"

I'd love to see the actual data

</comment><comment><USER24> What's the real performance of the system so far?

<comment> nv-vn Probably not very good. Voleon does all ML-based trading and what I've seen of their returns does not give me any confidence in ML-based trading having alpha. I would estimate that at best in a good year returns would be like 5% y/y in the long term, much less than the sustained ~7% that index funds offer especially when adjusting for risk. Just speculation but there's a lot of firms with much more capital, better tools, and teams of extremely intelligent people who have pretty poor returns because of how good the competition already is.

<comment><AUTHOR> I think you're comparing apples to oranges here. These funds manage billions of dollars of client money, which forces them into highly liquid markets with scalable strategies. That's quite different from how individuals or smaller prop funds can operate, trading off capacity for higher returns by trading in less liquid markets or with strategies that are "not worth it" for large hedge funds. If you must manage billions of client money then you are right in terms of competition, but as someone who only trades his own capital, you can see a lot higher returns.

<comment><USER25> Agreed. Many smaller, yet successful Hedge Funds limit the capital they manage for this very reason. Some strategies just don't work at certain scale.

<comment> nv-vn If the above is true, why would a fund not just allocate a small amount of resources to trade on OP's strategies. Either:

(1) OP's strategy performs worse than the alternative (2) They already do this, and have resources that allow them to outperform OP at their own strategy

If the returns are really meaningful, i.e. better Sharpe ratio than just holding $SPY or some dead simple strategy like that, then (2) must be true at least _somewhere_.

</comment></comment></comment></comment></comment><comment><USER26> Just curious to know do financial firms have implemented something similar to this

<comment> nv-vn Modern finance is built on top of this type of technology. There are hundreds if not thousands of firms participating in "quantitative finance," attempting to use computers/statistics to predict markets. The vast majority of trades go through major practitioners of this exact idea.

</comment></comment><comment><USER27> To be honest. I don't believe a word about the performance using AI. Especially if the article doesn't present the features and the NN architecture. Its always the question: would a super simple model perform the same way? And very ofter the answer is yes.

<comment><USER28> Lol this.. I once build a model (btc) that assumes this "we can't know the direction of market so we might as well guess", after spending months reading papers and trying to be "clever"

It starts off picking a random market direction (up/down) places bid (sorry I mean makes a trade). Then based on lots of tuning/backtest decided how long to be in position and what is the stoploss.. Think in the end the most "profitable settings" where something like :

$proft_size = 0.38% $stop_loss_size = 0.35%

Win-Continue-Direction = 3 rounds (after winning/losing do we change direction) So it probably in the end was Markov-model with random-start - <USER2> we had to label it :)

Oh and for fun it would also "martingale for x rounds" :P

Worked quite well for 3-4 days and was fun implementing it while watching "Billions" on TV in the background :D

<comment><USER27> Actually I'm not saying that you can't be profitable. Just saying that the fancy NN, won't work like magic in a noisy environment like financial time series. For other time series with periodic and other anomalies you can apply NN and you may have an edge - BUT for that kind of environments also classical methods are working quite good.

</comment></comment></comment><comment><USER29> trading != investing

</comment><comment><USER13> "Then, profits started decreasing and I decided to move on to other things and I lacked the motivation to go back into it."

Is this post about the one with decreasing profits, or a new one that is profitable?

</comment><comment><USER30> In some markets it is necessary to put the same length of fiber-optic cable between the colocated servers, so that being closer to the exchange's cabinet doesn't translate into an advantage. So obviously we're talking about extremely low latency, high-frequency trading. This carries a huge amount of prerequisites to even get started.

Not only are that, but there are many different order types besides "buy at market price, sell at market price". Then there's options, short sales, and more.

It goes deep. People devote 30 years of their career to this. Read the authors experience as a kind of warning, if you will.

<comment> nv-vn Agree to an extent, but not all money in quant finance is generated through HFT. Notably, I don't think funds like Rentec are really doing much to get low-latency [1]. Latency obviously does matter for any kind of quant trading, but to my understanding a good enough strategy + slippage models & the likes can overcome this.

[1] You can find a list of NYSE broker/dealers here: [https://www.nyse.com/publicdocs/nyse/markets/nyse/members/NY...](https://www.nyse.com/publicdocs/nyse/markets/nyse/members/NYSE_Member_Organizations.csv) \-- any firm where latency matters will need to be on this list to colo on the exchange.</comment></comment>


Drink two espressos to enhance long-term memory - <AUTHOR> http://www.newscientist.com/article/dn24855-drink-two-espressos-to-enhance-longterm-memory.html#.UtOabvagf-k

<comment><USER2> It seems like every stimulants these days are found to improve long-term memory or enhance working memory.</comment>


Tech firms begin to abandon Hong Kong because of security law - <AUTHOR> https://theprint.in/world/tech-firms-begin-to-abandon-hong-kong-because-of-security-law/465135/ <comment><USER2> Can we somehow stop posting sites that hijack the browser history?

<comment><USER3> how do you know this?

</comment></comment><comment><USER4> Would be more interesting to hear about the ones that don't.

</comment><comment><USER5> I wonder if this will include AWS.</comment>


You can't rely on a salary to get rich - <AUTHOR> http://www.businessinsider.com/you-cant-rely-on-a-salary-to-get-rich-2014-7

<comment><USER2> This is mainly about creating your own wealth. The first basic question is how do you want to spend your time? Since we are creatures of habit, having a scheduled 9-5 job with someone else directing you can be very comforting. It takes a special kind of person to go off and schedule your own day, work hard towards a goal, all while fitting in your normal life in between. With a job, you are forced to go to work at a set time, then when it's done you go home and continue your life for a few hours. Not everyone wants to spend that time creating wealth.

</comment><comment><USER3> Depends on how you define rich. It's all about income and expenses. The millionaire next door typically doesn't live in a massive house with extravagant cars.

Salary plus commissions can get you $250,000 a year as a sales person with little experience if you are willing to work hard and can handle rejection.

<comment><USER4> Do you have a recommendation on what to sell? How hard is hard? Can I work medium hard and earn $150k? Do I have to live anywhere in particular? Do you have to travel 100+ days a year?</comment></comment>