can one record multiple channels on a computer fed by mixer?

Question: I'm planning on buying a mixer which will be able to digest several microphones. It has struck me that connecting the mixer to a computer (through USB) I may not be able to record each microphone individually. Recording is done with Audacity. Would this epiphany of mine bear any weight? I have read about a multichannel recording device on this site and was wondering if there are any other solutions in concord with a mixer. Any insight appreciated.
Answer: Of course there are, any mixer that comes with an audio interface is what you are looking for.
For example :http://www.hifisoundconnection.com/Behringer-X32-DIGITAL-MIXER-32-Channel-16-Bus-Total-Recall-Digital-Mixing-Console-for-Live-Recording-Applications-X32
But they can be pricey !
You might be better off having an analog mixer and a separate audio interface.
but if you can't and actually need to go mixer + interface, a walk to your nearest music store could find you something that fits your needs.
added by Roman, see comments
The mixer I'm interested in (see comments) has stereo output, which means it can put out sound through two channels. This means you individually send input to one of the channels. For example, if you are recording with four microphones, you can have two left (1) and two right (2) or one left and the rest right.
Comment: Despite the incredible discount, it's a tad out of my price range. I'm leaning towards something like [Behringer QX 1202USB](http://www.amazon.com/Behringer-Xenyx-QX1202USB-Audio-Mixer/dp/B008O51872). It does have "Built-in stereo USB/Audio Interface to connect directly to your computer.". Would you say this is what I'm looking for?
Comment: This only handles 2 channels as being stereo! which means if you record a band you can't have separated instruments/channels but only the Sum of the sound in a stereo track, is this what u want ?
Comment: I see, there are two main "out" channels. In theory if I record with two microphones, I can have them in stereo, or in case of 4 microphones, two on one channel and two on the other? If you could please add all the info you've dished out in the comments to the answer I would very much appreciate it (things sometimes get lost in the comments).
Comment: yes exactly, you have 2 separate channels , you could record instruments 2 by 2 giving 1 channel to each and end up having everything separated. Or 4 channels and using the pan pot (L-R) you can "split" the guitars left and the vocals right, and this is the only draw back to this , cause its actually stereo and not 2 channel, you will have to pan things left & right to give them their own channel which might sound tricky if you monitor the recording or want to record a live set!
Comment: Seriously dude, i don't think any of these will do justice , just buy small mixer and a small maybe 4input interface like focusrite scarlett or something.
Comment: Ha, technically stereo is two channels, I didn't think about it that way before (I'm very fresh to this). This setup will be used to record podcasts and podcast like conversations so I'm not that worried about getting the details wrong in a live setting.
Comment: oh ok then :) so you are set, in the future if you want to go further you know where to look ) good luck


Why is fear of Hashem known as Yiras Shamayim?

Question: I often see that when people discuss fearing Hashem they refer to it as "Yiras Shamayim." Why is it called "Yiras Shamayim" and not "Yiras Hashem"?
Comment: [It *is* called _yir'as Hashem_.](http://he.wikisource.org/wiki/%D7%AA%D7%94%D7%9C%D7%99%D7%9D_%D7%99%D7%98_%D7%99) I suppose you mean to ask why it's *also* called _yir'as shamayim_?
Comment: Just to source this saying: Berachot 33b
Comment: @MonicaCellio, I've never heard that in colloquial speech AFAIR (though of course it's in the _pasuk_ I linked to).
Comment: Just to point out that "Shamayim" means sky or heavens.
Comment: I know the Pesukim say Yiras Hashem, my question is why in conversation we call it Yiras Shamayim?
Comment: Is this community variation?  We call it yirat Hashem.
Comment: I guess it must be - as where I live and grew up it called Yiras Shemayim - and hence this question.
Comment: maybe it's giving you an advice on how to build up yira shamayim. look up at the sky which is same color as the merkava or something like that, which is said regarding the techeles
Answer: Partly a comment on DoubleAA's answer, and partly an independent answer:
It is true that in general we find Chazal avoiding the use of Hashem's name where possible, and using alternative terms instead like (Hebrew) "shamayim" or "hamakom," or (Aramaic) "rachamana." We also don't find them using any of these terms as commonly as we use "Hashem" - for example, the expression "brich Rachamana" (corresponding to our "baruch Hashem") appears only eight times in the Gemara, and I've found only one example that might correspond to our "im yirtzeh Hashem" - in Sanhedrin 98a (אם ירצה אדון הזה, see Rashi there, although I think other commentaries explain it differently).
[I once saw in one of R. Avigdor Miller zt"l's books (don't recall which one) that this reflected the lower level of closeness to Hashem that they enjoyed as compared to the era of Tanach (when we find people using His name constantly, attributing events to Him, greeting each other with "May G-d bless you," etc.). In this connection he cites the statement in the Gemara, Yoma 69b: "Since they knew that Hashem is truthful, they wouldn't act falsely towards Him" - and explains that therefore the sages of the era of the second Beis Hamikdash and later wouldn't use terminology that would falsely imply a clear perception of His presence.]
On the other hand, at some later point in Jewish history it became more common to use the term "Hashem" to refer to Him, and to do so more often. (The importance of using phrases such as "baruch Hashem" got a particular boost through the efforts of the Baal Shem Tov, though of course the expression long predates him.) So it may simply be that the phrase "yiras shamayim" is common enough in the Talmudim and Midrashim that it stayed "fossilized" in that form, whereas as it became more common to bless Hashem for events in the course of casual conversation, people naturally would use the more familiar term.
Answer: My Rebbe explained that fear of Hashem is not terror of His power over us, but rather awe at how far above us He is. We express that distance by referring to Shamayim which is literally and figuratively unreachable. Thus, Yiras Shamayim is awe and admiration of Hashem's unknowable greatness.
Answer: The phrase yiras shamayim shows up many, many times in Talmud era writings, even in conjunction with verses from the Bible that specifically use the phrase yiras Hashem (see  Berachot 8a).
My best guess is that it is used to avoid saying God's name. We choose the euphemism of "Shamayim" as an allusion to the verse in Yonah 1:9
ויאמר אליהם עברי אנכי ואת יקוק אלהי השמים אני ירא אשר עשה את הים ואת היבשה:
And [Jonah] said to [the sailors] "I am a Hebrew, and it is the Lord, God of the Heavens [Shamayim], the maker of the land and the oceans whom I fear." (my translation)
Comment: Then when something good happens to you - why don't you say Boruch Shemayim instead of Boruch Hashem?
Comment: @GershonGold "Hashem" is also a way of avoiding saying His name.
Answer: In Divrei HaRav (p. 157-158), Rabbi Joseph B. Soloveitchik is quoted as explaining that the concept of fearing God is based on the vast difference between our finite existence and God's infinite existance, whereas the concept of love of God is based on the close personal connection God forges with each of us. Accordingly, he explains, for the latter concept we use the term אהבת השם to signify our being on a "first name basis" with God, while for the former concept we use the term יראת שמים to signify the great distance between us and God.
Answer: Yirat Shemayim is not only awe of Hashem, but all of his heavenly creations as well.  We look "up" when we feel that awe, towards the heavens in general.
Comment: However Hashem is still that what we fear, not the Shamayim.
Comment: @avi, "Al tira avdi Yaakov"?
Comment: Yirah is not fear, it is awe, Pachad is fear.
Answer: The Kli Yakar Breishis 1:6 mentions the Gemara in Chagiga 12a how when Hashem created the heavens they kept on spreading until Hashem screamed at them and then it stopped spreading. Based on this Kli Yakar I heard from Rabbi Menachem M Lerner of Anshei Sefard in Lakewood that the reason we say Yiras Shamayim is to remember the Yira the Shamayim had and continues to have to this very day, and that is how our Yirah should be from Hashem.


Does a PoA network use gas?

Question: I understand PoW uses gas to counter a DDoS attack. What about PoA? Is gas also used in PoA networks?
Answer: Proof of Authority networks still use gas to power Contract calls and Transactions.
Answer: EVM-based PoA chains use gas because gas is an integral part of the EVM. Other PoA chains might use different spam protection mechanisms or--in setups where the authorities trust each other as well as all transaction senders--go without one altogether.

Does a PoA network use gas?


Number of Substitution boxes

Question: How many possible 16 bit S-boxes exist? (AES uses 8 bit substitution boxes)
I first taught of calculating 128(keysize in bits)/8(bits) =16, but I believe it's wrong.
Answer: An s-box is a bijective function $f: \{0,1\}^b\rightarrow\{0,1\}^b$. This reduces the question to "how many of those $f$ exist".
To see this easily, imagine domain and image of this function as two boxes with $2^b$ elements. How many different sets of arrows can you imagine between those two sets?
For the first arrow, you have $2^b$ choices. For the second arrow, you have $2^b -1$ choices. For the third, $2^b-2$, and so forth to the last arrow, where there's one choice left.
Multiplying those together, you would get $2^b(2^b-1)(2^b-2)\dots 1=2^b!$ possible s-boxes, so in your 16-bit case that makes $2^{16}!$ possibilities.
To put this more mathematically, an s-box is a permutation of $2^b$ elements, and there are $2^b!$ such permutations.
Comment: Just a comment, since $2^b$ factorial is much larger than $2^b$, this also demonstrates that a $b-$bit key for a $b\times b$ cipher [after alll a block cipher has to be invertible for each key, thus be a permutation] can only sample a small subset of possible permutations. One can use Stirling's approximation to approximate the factorial for clarity.
Comment: Seems correct to me, thank you very much for your answer and for all the details, it's so much clearer now!
Comment: Yes. It always bothers me that we use a keyspace of $2^b$ elements, where there are $2^b!$ permutation functions for a block cipher...

Number of Substitution boxes


What are the best conditions for basil?

Question: What are the best conditions for basil to grow? I live in the UK and it never seems to last that long. Recently I've been putting the plants in the shade and drenching them in water, which seems to be working so far.
Answer: There is one magic tip to prolonging the life of a basil plant: Pinch the flowers as soon as they appear!
Plants such as basil basically just grow till they flower and then stop. As far as the plant is concerned, it has crossed the finish line and there's nothing left for it to do. So when you keep taking away leaves for your culinary needs, you're weakening the plant.
On the other hand, by pinching the flowers, what you're doing is effectively pushing the finish line forward, so the plant still runs towards it. So you'll get new growth every time you pinch them off and your plants will be lush and last longer.
Here is a nice illustration from this site that shows where to trim the flowers to encourage growth. The article is a good read too!
Comment: Does this also go for other plant, for example spinach?
Comment: Don't forget to pick the larger leaves first, allowing the smaller ones to grow. Along with pinching the flowers and not watering later in the day this will help you get the most out of your basil.
Answer: Additional to the other answers, basil famously doesn't like to be damp overnight. Water mornings, not evenings.
Comment: ooh thanks for this this. I always water everything at night, will have to start finding time to water my herbs in the mornings.
Comment: How do we know this to be true?  I have 3 varieties of basil that are sopping wet every night, either from dew or from rain. The plants grow so well, I've resorted to freezing my pesto, since I simply can't eat it as fast as it grows.
Comment: I believe that it's best to water most all plants in the morning rather than night.  Watering at night makes them wet all night, which is promotes disease.  This goes for grass, vegetables, etc.  I personally like using a timer to water very early in the morning.
Answer: I am attempting to grow Basil for the first time also, but mine seem to be doing pretty well. From what I found basically they needed a to be planted in soil that will drain well. In a quick google search I found this site that added a few other things:

will not survive indoors
susceptible to cold and frost, and to drastic temperature change
Comment: I've got basil indoors and it is surviving if not thriving.  The main problem seems to be that my pot doesn't drain well, not that the plant is indoors.
Comment: My indoor basil is doing really well because it's at the eastern window sill above kitchen sink and we don't draw a blind on the window except midsummer so gets loads of sun.
Comment: I've also read that temps below 50°F can damage the plant -- it may not recover.
Comment: Plant may not do well in soil indoors, but to say it won't survive isn't necessarily true.  Example: basil can easily spend it's whole life indoors under growth lights in a hydroponic setup.
Comment: Nonsense. My basil is still growing like a weed in the compost it came with from the supermarket, and after I hacked almost all of it off to go into the freezer, it's come back with a bang within a couple of weeks. It's thriving indoors.
Answer: Basil, and herbs in general, do not need to be fertilized. Consider that basil grew well in Mediterranean geographies in the crags of rocks. So don't overwater, fertilize, or put it anywhere but in full sun.
Also, @yoda is 100% right, you have to keep on top of pinching the flowers off. But as a rule of thumb, if it has been a while, never remove more than 1/3 of the foilage at any one time.
Answer: Some things I've noticed about basil:

Basil is deep-rooted.  I have medium size basil plants in fairly large pots (pots which originally contained 5ft pears trees).  The basil roots have grown out of the drain holes and anchored the pots to the ground.  Basil roots can easily exceed 1ft in depth.

Basil can root from the stem like tomatoes.  I discovered this while observing a sprout that had a dead spot in the stem which dried to a thread and cut off the root system from the leaves.  Yet, the leaves looked healthy.  It was confounding.  Figuring the leaves must be drawing nutrients from the stem which was touching the ground, I covered the stem with soil, and now it's a full-size basil plant.  Since this discovery, I hill-up my basil plants like I do tomato and potato plants.  It may be possible to propagate basil by cutting off a stem and sticking it directly into the ground.  Tomato plants will grow this way.

Like tomatoes, basil doesn't care much for an overly acidic soil and appreciates a good supply of calcium for strong cell development and magnesium for the abundance of chlorophyll it produces.  My basil responds well to lime, calcium nitrate, magnesium sulfate, and potassium sulfate (calcium, sulfate, magnesium, and potassium are the minerals most leached by rain, in that order).
From The World's Healthiest Foods we can see basil has a "very good" rating next to calcium and iron and a "good" rating next to magnesium and potassium.  The 59 mg Ca + 12 mg Mg + 96 mg K must come from somewhere.  Minerals aren't manufactured.

Any suggestion that basil doesn't like water is absolutely false.  We've had record-breaking amounts of rain this year.  April, May, and June were 10 inches each and we had 15 inches for July.  That's a year's worth of rain in 4 months and double or triple the annual rainfall of western or mid-western states.  In spite of all this water, a few days I ago I had to add 1 liter to each plant in response to wilting.  The plants perked up the next day and resumed growing gangbusters.  The basil was the only plant I observed wilting due to lack of water, leading me to believe basil is particularly fond of water.

Basil is salt-sensitive.  Too much KCl can wipe out a stand.  The big bags of 10-10-10 and 13-13-13 are not worth much as fertilizer.

Additionally, there is not a night that passes without my basil being sopping wet... either from rain, dew, or my spraying with a water hose.  If basil doesn't like to be wet at night, it's hard to tell from the overwhelming production of leaves occurring on Genovese, Sweet, and Large-Leaf basil.
If basil doesn't like to grow indoors, it's probably because of a small pot, lack of light, not enough water, and lack of humidity (central air and heat dries the air).
Comment: I'm a newbie balcony gardener and Basil is my favorite herb to grow. It likes water and would even tolerate being slightly wet all the time although well-draining soil is ideal. I grew a sweet basil from a cutting when my main plant was only a few inches tall. I put it in water to let roots grow but it looked like it was near death after a few days. I put it directly into soil and amazingly, it lived! Similarly, a stem dropped off my holy basil (tulsi) for no reason. There were small bumps at the stem's base. On a hunch, I stuck it in soil and it grew impressively long roots in just a few days
Comment: @Tintin Yes, that's similar to the observations I made.  Cover a stem with dirt and it will grow roots.  Tomatoes will do the same.  You can pull a sucker off a tomato plant, make a hole with your finger, stick the stem in the ground and it grows another tomato plant.
Comment: I've rooted store bought basil in water. Nothing happened for about a week then almost overnight it sprouted many thick white roots.
Comment: +1 Never underestimate the value of a larger pot. It makes things so much easier for so many plants. However, other needs need to be met, too, to make it worthwhile (e.g. sun, water, etc.); ideal plant care isn't the same for every container. What's best for a plant in a tiny pot isn't what's best for a plant in a huge pot, nor vice versa.
Comment: For example, tiny pots dry out faster and are less suitable for strong sun (because it makes that problem more severe). Large pots can potentially be problematic if the sun isn't strong enough, unless the plant is pretty big for it.
Answer: In the past it has grown almost like a weed in our pots on our deck here in North Texas. Admittedly we deliberately help it to re-seed itself: we grow it as an annual and winter frosts kill it. The location is hot (often 100F+) and full sun in the afternoon, but they do take quite a bit of water. So perhaps shade is the wrong thing?
Answer: Basil is a great companion plant.  Have a search for 'basil' on this list of companion plants to see what's good to plant nearby.

What are the best conditions for basil?


What does "ease" mean in the phrase "dharma gate of ease and joy"?

Question: What is the "ease" of the "dharma gate of ease and joy"? Can an unelightened person achieve it outside seated meditation?
Ought I imagine everything is difficult, or everything is easy? How can we be effortful in our everyday lay tasks?
Comment: See also [What does "joy" mean in the phrase "dharma gate of great ease and joy"](http://buddhism.stackexchange.com/q/17257/254)
Answer: Dogen means that when you practise zazen you let go of troublesome thoughts. When you do this your state is one of ease (in the sense of 'being eased' rather than 'easy').
I think Dogen would have agreed with Hui Neng on the subject of enlightened and unenlightened people : One foolish notion is enough to shut off Prajna, while one wise thought will bring it forth again.
When not doing zazen, we should still be practising awareness (some sanghas refer to work in the temple as 'working meditation'). Although sometimes we need to think about difficult stuff. Zazen is just a time when we don't have to and can let go of everything.
Answer:
What does "ease" mean in the phrase "dharma gate of ease and joy"?

It means that ones five spiritual faculties are balanced.
In meditation practice, e.g. Samatha meditation it means that if the mind strays from the primary meditation object, i.e. the breath, then one does not force attention back onto the breath. Instead it comes naturally and without striving.
Joy related to practice, arises when ones practice gains momentum meaning that one spends little but right effort into cultivating wholesome habits and purifying the mind. Joy arises easily in beings that are non-attached. There is a lightness of mind because they do not carry any bagage from one moment to the next.
Ease and joy arises when one interacts with reality instead of reacting. One is seeing reality for what it is, thereby gaining freedom from mental proliferation.
Answer: The short answer to what is ease is sukha. The more unattached you are, the more effluent-free, and unbinding you are, you get to experience this positive aspect sukha.
Sukha can be translated as pleasure, happiness, bliss, or ease. It is a pleasurable experience to have. In  DN 9: Potthapada Sutta Buddha says how if one could outgrow ones gross self, and enter the mind-made – the sense of self that can be developed in meditation - your defiling mental qualities will be abandoned, bright mental qualities will grow, and you will enter into this state of 'Ease'. Then there is there is joy, rapture, serenity, mindfulness, alertness, and a pleasant/happy abiding.
Even outside of meditation you can experience such a state if you are prepared to discipline yourself as per the scriptures. You can get an idea about what it takes to discipline self in the Ganhaka Moggallāna Sutta in Majjima Nikāya.
First Buddha will advice one to come and be virtuous first – to discipline yourself from virtue, to make your life pattern good. Then he will get you to protect your six faculties (eyes, ear, etc.). For eq. when you see a figure from your eyes, low defilements such as craving and anger could be formed in you if your eyes were not disciplined. Protecting the last faculty, the mind, is to safeguard your mind without letting defilements to arise – to discipline your mind well.
The next level of discipline is when it comes to food. This is how you go about it: Now you have to eat mindfully (with the realization of true meaning of eating), inquiring wisely. That is, I am taking this food not for the strength, not for the satisfaction, not for the good looks, or not to play. I am taking this food only to continue this life, to get rid of tiredness, and as to a help to continue the solitary life away from lay life. I will free from old pains and stop making new pains by taking this food. I will continue this life and have a correct and painless life by taking this food.
At this stage you are ready for mediation, and to experience true Ease.


Successive creation of over 1000 posts causes 404?

Question: I'm developing a bulk importer. It basically takes images and converts them into posts. Each image will be created with 10 different related posts therefore each image will represent/create 11 posts. If I import 100 images, the plugin would have to create 1100 posts successively. The problem is Wordpress throws a 404 error in the console while the plugin is creating the posts. Here's the exact error:
Failed to load resource: the server responded with a status of 404 (Not Found) http://www.example.com/wp-admin/admin-ajax.php

The error log says:
WordPress database error MySQL server has gone away for query ...

The plugin does the import by uploading the images first and then create the posts after that. It's in the creation of the posts when the error is thrown.
It's important to note though that the error does not occur if I import under 20 images.
As this is AJAX, I don't have other error data that would help me diagnose the problem. But I'm guessing the server somehow stops at a certain point while being asked to create posts. Any thoughts?
EDIT: As requested by @kaiser, here's the function the creates the post for each image:
public function create( $posted ) {
    $post_ids = array();

    foreach ( $posted['attachments'] as $file_id ) {
        $file_data = $this->get_file( $file_id );

        $post = array(
          'post_title' => $posted['titles'][$file_id] ? $posted['titles'][$file_id] : $file_data['name'],
          'post_content' => '',
          'post_type' => 'xxx',
          'post_status' => 'publish',
          'post_author' => get_current_user_id(),
          'tax_input' => array(
                                'xxx_type' => array( post_type_term_id() ),
                                'xxx_cat' => array( $posted['term_id'] )
                              )
        );

        // Create post
        $post_id = wp_insert_post( $post );
        $post_ids[] = $post_id;

        // Form post metadata
        $metadata = xxx_metadata_defaults();

        // Attach event date to this post
        $metadata[ 'event_date_meta_key' ] = date( 'Y-m-d H:i:s', strtotime( $posted['date'] ) );

        // Add meta that determines if this post is imported by this plugin
        $metadata['xxx'] = 'yes';
        // Record attachment id for later use
        $metadata['xxx_id'] = $file_id;

        // Update metadata
        foreach ( $metadata as $key => $value ) {
          update_post_meta( $post_id, $key, $value );
        }

        // Set file as the post thumbnail for the post
        set_post_thumbnail( $post_id, $file_id );

        // Create related
        $this->create_related( $posted['group'], $post_id, $file_data );

        do_action( 'create_related_posts_complete', $post_id, $posted['term_id'], $posted['users'] );
    }

    return $post_ids;
}

The line below creates another 10 posts.
// Create related
$this->create_related( $posted['group'], $post_id, $file_data );

I'm not sure how to split the query since all the files are fetched from the form and created as posts at once so maybe I have to use sleep() as @kaiser suggested. But how much time should I assign to sleep? Will it depend on some php.ini config -- max_execution_time?
Comment: [enable logging of errors to a file](http://codex.wordpress.org/Debugging_in_WordPress)
Comment: `MySQL server has gone away` is probably a timeout error. Not sure how your import works, but you should break it up into multiple consecutive requests if you're not already.
Comment: @Milo: I just included the error in the log file. Thanks!
Comment: Please show us your code  - the relevant parts.
Comment: WP has no issue creating large amounts of posts, but it takes time and resource toll. You are probably knocking out MySQL server, which is separate beast entirely from WP.
Answer: What I did for custom importers:

Add a dedicated menu page in admin
Step-process it and echo in between
Use sleep() after each import


What is the correct way to transliterate O'Neil or a similar name?

Question: Not sure how to correctly write this - as one word, separate?  Do I retain the apostrophe?
Answer: Usually the apostrophe in personal names retains, so we have in translation Юджин О'Нил, Шакил О'Нил and actually a lot of other О'Нилs. The same about Жанна Д'Арк (or д'Арк) or Габриеле Д'Аннунцио (or д'Аннунцио) etc.
This is what you'll see in newspapers and books. In official documents it could be more tricky though. I won't be surprised that there are no regulations about this particular case so say some O'Neil will decide to become a Russian citizen he can be written just as О-Нил or О`Нил. Bureaucracy is a bureaucracy so I can imagine some stubborn official (check out for instance, this post) - but this has nothing to do with Russian language, so let it be )
Comment: Just a fun fact: I've seen the name of the mathematician d'Alembert pretty many times in the Russian texts and it's always transliterated as Даламбер. Otherwise, I fully agree (for what my poor Russian skills are worth :—)).
Comment: @Ramillies sure, historical spellings can go against any rules. Few Japanese words, city names among them, are not spelled according to Polivanov's system for the latter did not exist when they came in use.
Comment: @bipil: Absolutely. That just came to my mind when I read the question, that's all.


HOME/bin not a valid identifier

Question: I am a grad student who has fallen into maintaining a server on a linux-Ubuntu machine - we work in Ontopia and Wandora, two programs that like to mess with Java environments.  I am learning as I go which means I probably messed up something stupid; I believe I was trying to update the version of Java that was running on Ubuntu when I  broke it.
The login page loads, I enter  my password, it reloads.  This happens for all users, guest, and test accounts.  This happens in Ubuntu, Ubuntu2d, lubuntu and after the graphicx failsafe recovery business.
Logging in through the shell (after Alt F3) gives me:
-bash: export: 'HOME/bin' : not a valid identifier

but lets me navigate through the system and accounts with no other apparent problems.
My .xsession-errors gives:
/etc/gdm/Xsession: 3: export: HOME/bin: bad variable name

when I enter which java I get:
/usr/lib/jvm/java-6-openjdk-amd64//bin/java

I could see how this might contribute to the problem, but I've no clue how to change this path [and can't find where to do so online].
My environment files includes CLASSPATH AND CATALINA_HOME variables that I don't think are relevant, as well as:
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:"
JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64:/usr/lib/jvm/java-6-openjdk-amd64
JRE_HOME=/usr/lib/jvm/java-7-openjdk-amd64/jre:/usr/lib/jvm/java-6-openjdk-amd64/jre

Content of java.sh:
export JAVA_HOME=/usr/lib/jvm/java-6-openjdk-amd64/
export PATH=$JAVA_HOME/bin:$PATH
export PATH=$PATH:$JAVA $HOME/bin

Content of /etc/bashrc:
# System-wide .bashrc file for interactive bash(1) shells.

# To enable the settings / commands in this file for login shells as well,
# this file has to be sourced in /etc/profile.

# If not running interactively, don't do anything
[ -z "$PS1" ] && return

# check the window size after each command and, if necessary,
# update the values of LINES and COLUMNS.
shopt -s checkwinsize

# set variable identifying the chroot you work in (used in the prompt below)
if [ -z "$debian_chroot" ] && [ -r /etc/debian_chroot ]; then
    debian_chroot=$(cat /etc/debian_chroot)
fi

# set a fancy prompt (non-color, overwrite the one in /etc/profile)
PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '

# Commented out, don't overwrite xterm -T "title" -n "icontitle" by default.
# If this is an xterm set the title to user@host:dir
#case "$TERM" in
#xterm*|rxvt*)
#    PROMPT_COMMAND='echo -ne "\033]0;${USER}@${HOSTNAME}: ${PWD}\007"'
#    ;;
#*)
#    ;;
#esac

# enable bash completion in interactive shells
#if [ -f /etc/bash_completion ] && ! shopt -oq posix; then
#    . /etc/bash_completion
#fi

# sudo hint
if [ ! -e "$HOME/.sudo_as_admin_successful" ] && [ ! -e "$HOME/.hushlogin" ] ; then
    case " $(groups) " in *\ admin\ *)
    if [ -x /usr/bin/sudo ]; then
    cat <<-EOF
    To run a command as administrator (user "root"), use "sudo <command>".
    See "man sudo_root" for details.

    EOF
    fi
    esac
fi

# if the command-not-found package is installed, use it
if [ -x /usr/lib/command-not-found -o -x /usr/share/command-not-found/command-not-found ]; then
    function command_not_found_handle {
            # check because c-n-f could've been removed in the meantime
                if [ -x /usr/lib/command-not-found ]; then
           /usr/bin/python /usr/lib/command-not-found -- "$1"
                   return $?
                elif [ -x /usr/share/command-not-found/command-not-found ]; then
           /usr/bin/python /usr/share/command-not-found/command-not-found -- "$1"
                   return $?
        else
           printf "%s: command not found\n" "$1" >&2
           return 127
        fi
    }
fi

Content of ~/.profile:
# ~/.profile: executed by the command interpreter for login shells.
# This file is not read by bash(1), if ~/.bash_profile or ~/.bash_login
# exists.
# see /usr/share/doc/bash/examples/startup-files for examples.
# the files are located in the bash-doc package.

# the default umask is set in /etc/profile; for setting the umask
# for ssh logins, install and configure the libpam-umask package.
#umask 022

# if running bash
if [ -n "$BASH_VERSION" ]; then
    # include .bashrc if it exists
    if [ -f "$HOME/.bashrc" ]; then
    . "$HOME/.bashrc"
    fi
fi

# set PATH so it includes user's private bin if it exists
if [ -d "$HOME/bin" ] ; then
    PATH="$HOME/bin:$PATH"
fi`
`

Comment: Output of grep "HOME/bin" ~/.* `/home/slis/.bash_history:CATALINA_HOME/bin/startup.sh
/home/slis/.bash_history:CATALINA_HOME/bin/startup.sh
/home/slis/.profile:if [ -d "$HOME/bin" ] ; then
/home/slis/.profile:    PATH="$HOME/bin:$PATH"
/home/slis/.profile_back:if [ -d "$HOME/bin" ] ; then
/home/slis/.profile_back:    PATH="$HOME/bin:$PATH"
/home/slis/.xsession-errors:/etc/gdm/Xsession: 3: export: HOME/bin: bad variable name
/home/slis/.xsession-errors.old:/usr/sbin/lightdm-session: 3: export: HOME/bin: bad variable name`
Now what?
Comment: I'm going home, thanks for your input and I'll check back tomorrow :-)
Comment: .profile loads .bashrc, post its content too.
Answer: you need to look at your dot files (eg if you use bash, it will be .bashrc, .bash_profile) for a export PATH=.... entry.
By the looks of it one of the entries  will be HOME/bin change this to $HOME/bin, log out and back in and the error should go away
Answer: I think the problem is here:
/etc/gdm/Xsession: 3: export: HOME/bin: bad variable name

Edit /etc/gdm/Xsession (sudo nano /etc/gdm/Xsession) then go to line #3 and change HOME/bin to $HOME/bin.
Comment: ooh, nano is better than vi! Thanks for that...but There is no line with HOME/bin in my Xsession file :-(
Comment: First: in `java.sh`, there is the line `export PATH=$PATH:$JAVA $HOME/bin` - missing a `:` between `$JAVA` and `$HOME`. (That would not create the symptom you described; maybe a "command not found" or "is a directory" error.). And second: No jokes involving `vi` or `vim` - that's a very emotional topic. (Oh: and welcome to Ask Ubuntu!)

HOME/bin not a valid identifier


Are there big differences in speed between different hard drives?

Question: When buying a (consumer-level) hard disk, I normally only pay attention to storage capacity. Is it worth to compare drive speeds also, and if yes, how can this be done?
Comment: @Molly:  Why CW?  Drive speeds are quantifiable, how to find them out is objective, and there isn't that much subjective about whether the difference is worth looking at.
Answer: Yes, it's worth it to compare drive speeds if getting your data more quickly holds any advantage for you.  For the home user, it's typically a matter of convenience.  For a professional server, faster drives mean faster performance under disk I/O load.
Assuming you're looking at drives with the same interface, the most common speed measure, and usually the most significant, is the RPM of the platters.  Common values include 4200, 5400, 7200, and 10,000 RPM.  High end SCSI drives and the like can go up to 15,000 RPM.
You may see values like seek time, access time, and the like.  This will usually be similar for drives of similar rotational speed.
Also, you'll see disk cache sizes, typically a larger cache means it can take better advantage of temporal locality.
Comment: For my main hard drive, the one my operating system and applications are installed on, I wouldn't put less than a 10,000 RPM drive (if a desktop, 7200 if a notebook). This will noticeably speed up everyday computer use (because of virtual memory etc) see Jeff's *2007* post: http://www.codinghorror.com/blog/archives/000800.html
Comment: Honestly, I have to give the resultant performance increase per unit cost a resounding "meh" re: going from a 7200 rpm to a 10k rpm.
Comment: It's just not that important to me as much as having full mirroring is.
Answer: If performance is your main concern, it's also worth considering whether solid state drives (SSDs) suit your needs. They are (usually) significantly faster than (premium) hard disk drives. But SSDs also cost more per GB, so are often used just for the boot/OS/applications drive; HDDs must still be used for bulk data storage.
So, for me, the relatively minor differences in HDD performance are almost irrelevant because SSDs can fundamentally perform better.
Answer: Tom's Hardware has some charts of hard drives benchmarks, using h2benchw.  Reads are what you spend the bulk of your time doing, but there are write charts there, too.
Read Access Time
This tells you how responsive the drive is, how quickly it responds to a sudden small request.  I believe this is what best gives the impression of hard drive speed.  It's analogous to the "first page out" for printers.  Less is better, so the best performer is at the bottom (those boneheads).
Average Read Throughput
This chart will tell you how fast it should make medium to large copies.  Using the printer analogy, this would be "pages per minute".  More is better, so the best performer is on top.
Storage Review's Performance Database has more benchmarks.  They've slowed down the reviewing pace in recent years, but it can give you an idea as to how a family of hard drives is expected to perform.  Ignore the IOMeter benchmarks; they only apply to the heavily parallel access patterns found in servers.
Manufacturer supplied stats are a starting point, but you really have to consult benchmarks to have an idea of real world performance.  On the Storage Review benchmarks, notice how the 7200 RPM Hitachi beats a 15K RPM drive on the Office Drivemark test.  Just citing spindle speeds wouldn't tell the whole story here.

Is it worth to compare drive speeds [sic]

For a system drive where the OS resides, yes.  It's one of the slowest data-access components especially considering its high utilization.
For a storage drive/secondary drive, not really.  Benchmarks are only useful here to find out if a drive is particularly slow.  For this, just look for reliability, good customer feedback, low price and a long warranty period.
Comment: **Average Read Throughput** link correction -> http://www.tomshardware.com/charts/2009-3.5-desktop-hard-drive-charts/h2benchw-3.12-Avg-Read-Throughput,1010.html
Answer: Hard disk performance is hard to condense into one number. The primary factors which will affect performance are, in approximate order of importance:

Spindle rotation rate (for example, 5400, 7200 RPM)
Platter linear density (number of bits per inch)
Cache size

Random I/O performance (reads or writes to "random" locations on the disk) is almost completely dependent upon the rotation rate. Sequential I/O performance is dependent upon the product of the rotation rate and the bit density.
You can get 10K/15K RPM drives, but they are smaller (less density!) than 7200 RPM drives. That's great for a database (largely random access I/O), but they are a total waste for storing videos.
Cache size mostly helps with writes (if you enable disk write caching), because the drive can schedule the writes more efficiently, reducing the amount of seek time per write. It doesn't help that much with reads because your OS already does read caching with a lot more memory.
Answer: But don't forget to take into account, that faster drives are also more noisy than slower drives due to their highspeed they need bigger (and more noisy) fans and more cooling.
If you have a server in your serverroom noise isn't a real big problem. But with a desktop system and you in front of it it will definitely be.
But i agree on my precommentators. If you are going for a faster harddisk you have to look out for:

Speed (RPM)
Cache
Interface

(Not taking into account, that there are high-priced super disks with anti-noising facilities like liquid cooled, gel equipped and something like that)
Comment: ...can be more noisy...

Samsungs (ranging from earlier P120 drives to the latest F1 drives) have a reputation as being quieter than most drives, but also being among the fastest (and one of the cheapest and most reliable, while we are blowing their trumpet!) of comparable drives. Older raptor drives were considered very noisy,but later versions have improved).

If noise is an issue, I refer anyone interested to SCPR.com.
Answer: In general you want a faster drive and more cache.
Faster drives have a lower seek time and higher transfer rate.
Large caches help keep the transfer full.
For example, if you use a site such as Newegg, you can filter on drive speed, capacity, interface, and cache via the advanced search :)
Answer: Yes, hardisks comes with different speed of rotation. Higher speed of rotation means higher data transfer speed. Normal RPM (Rotation Per Minute) values of hard disk drives are 5200, 7200, 12000, etc.
When you buy a hard disk, look for the RPM value also.
Answer: While I pretty much agree with what other posters have said, in a sense, you don't really need to worry.
Although there are clear differences in performance between certain classes of drive (e.g. 5400rpm SATA vs 15000rpm SAS drives), there is not a lot of difference between drives in the same class. If you compared a number of 7200rpm SATA drives of similar ages and capacity, the differences would be minimal and could be countered by other factors such as RAID and partitioning regimes.
Noise, heat, cost and reliability often vary much more and are perhaps more pertinent to most buyers.
Perhaps you could mention what kind of drives you are considering and the purpose you have in mind, in order for us to give more focused advice? I'm assuming that you are a consumer and are pondering choices of SATA drives?
Answer: Another concern .. if the hard drive is to be used in a laptop, usually the faster the hard drive, the more power it uses and therefore runs your battery down quicker.
Answer: But if you can afford a Solid State Drive, that would be faster than traditional hard disks.
Comparison of SSD with Hard Disk Drives


Shoes for Weightlifting

Question: What shoes have you found to be most effective for exercises like squats and deadlifts etc.?
Comment: I ended up getting a pair of [Merrell barefoot running shoes](http://www.merrell.com/US/en-us/Product.mvc.aspx/22875M/50390/Mens/Barefoot-Run-Trail-Glove), and they've worked great for me so far. I wanted to get the VFFs but these shoes fit my feet much more comfortably. Since they have minimal cushioning and a wide toe box, you don't get a compressible sole or wobbliness. They're also very versatile, and you can take them for a run or a hike. There are also several other brands of "minimal" style shoes that could probably double as weightlifting shoes: New Balance and Terra Plana come to mind
Comment: Could you consider adding some more information, like what shoes you currently wear and any experience you have with shoes during weightlifting?
Comment: I wear a pair of Vans slipons most of the time. Nice stable sole.
Answer: When doing any weight training that involves the legs/feet, you want a shoe that provides:

Hard, incompressible sole. Avoid squishy sneakers, as they are a bit like doing push-ups on a mattress.
Wide & stable. You don't want to be wobbly.

Specific cases:

Any type of squatting (including the clean, jerk, snatch): a raised heel is advantagous when squatting. Proper weightlifting shoes are your best bet, such as the ones available at Rogue Fitness, Pendlay Barbell or Eleiko.
Just about everything else (including deadlifts): you want to be as low/close to the ground as possible. Barefoot or in socks is ideal when conditions allow. If not, Chucks and Vibram Five Fingers are good alternatives.
Comment: +1 for Vibrams. I love these for squats and deadlifts.
Comment: If you could only choose one pair for squats, deadlifts and presses, would you prefer a raised heel or not?
Comment: If you're wearing Olympic shoes with a raised heel, you best be launching some real weight in the air. For 99% of lifters a pair of low top converse will work just fine.
Comment: +1 for raised heel when squatting
Comment: Are you saying one should change their shoes when squatting vs. deadlifting?
Answer: To some degree I think the shoe needs will vary based on individual anatomy and flexibility. For me (43yr old male with 2yrs of heavy lifting, 6 months olympic weightlifting) a taller and stiffer heel was needed to deal with my ankle flexibility issues. Without the higher heel I tended to end up with my weight to far forward onto my toes rather than heels while lifting.
I've been through 3 different pairs in the past year and so far have liked the Risto Olimpico the best. They seem to have the biggest heel to toe drop of the ones I've tried and are definitely one of the most comfortable. I'be also tried the Pendlays (had a good heel but were very uncomfortable for me) and the Adidas Powerlift Trainers (very comfortable but not a big enough heel for me). Others at my gym swear by the Nike Romaleos and the Adidas Adipower shoes but I have never tried those.
Answer: I feel like it really depends on the lift. Pretty much unanimously, a lifter performing oly lifts or front squats will benefit from an oly lifting shoe. Equally, a flat bottom shoe, such as chuck taylors or ballet slippers will help out during the deadlift. However, I feel like the back squat has a wider variance in what lifters prefer to lift in.
Answer: A cheap good shoe to start in - Adidas Spezial. It is close to the ground, is very sturdy and does not cost a whole lot, like specialized shoes do.

Shoes for Weightlifting


How to check if a Linux server is clean from rootkits/backdoors/botnets etc.?

Question: In case a Linux server was exposed to the internet with extreme low security policy (r/w anonymous Samba folders, Firebird database server with default admin password, no firewall, etc.)  for a week, then how do I make sure the system is not compromised without full formatting&reinstalling, accessing it only remotely via SSH?
Answer: Normally I'd suggest a local check with a tool such as chkrootkit but if the only way to run the check is to do so remotely, then I would recommend that you try Rootkit Hunter instead.
Rookit Hunter checks for rootkits and other such activity by running tests such as the following (see Project Information for more details):

MD5 hash compare
Look for default files used by rootkits
Wrong file permissions for binaries
Look for suspected strings in LKM and KLD modules
Look for hidden files

I want to add that as others have said, the only sure way to ensure there has been no tampering with your service is to rebuild it.  These tools work well, but they are not a 100% guarantee of success.
Answer: OSSEC checks for rootkits and detects suspicious activity.
Answer: I know this answer isn't what you want to hear but here we go anyways. There are some tools that can check the system the best way to ensure the system is clean is to wipe the server and rebuild. I would do the following:

Remove the computer from the internet
Backup Data and Config information to remove devices
Format Storage
Reinstall Base/Standard Setup/Updates
Reconfigure Server using old data as reference
Restore user data

Here are some resources I would start reading if you haven't already.
[link text][1]
link text
link text
link text
[1]: http://www.sans.org/reading_room/whitepapers/linux/linux-rootkits-beginners-prevention-removal_901"Linux Rootkits Beginners"
Answer: Also not the answer you want but if there is a possibility that a system was rooted, it may be very difficult to be 100% sure the system is clean.  Rootkits are designed to be difficult to detect. If you run the various root checkers and it checks out clean, then "most likely" your system is clean.
If security is a concern, I would consider rebuilding it as above poster just said or restoring it from good backups.
Answer: You really need to be proactive here.  There's no reliable way to detect rootkits on machines, you thus need to prevent them getting there in the first place and find ways to detect them upon entry (e.g. via tripwire and locked down interfaces).
If you think a machine has been exploited in any way, you really need to reinstall - there's no guaranteed way to clean it up short of a reinstall.  By far the safest option.
Answer: RKhunter, Tripwire etc are great, but really only of benefit if they were installed before the incident - this is because they are great for detecting whether key files have been changed.  If you install RKHunter now and run it, it will detect the inclusion of many rootkits, but it won't detect any backdoors an attacker opened up in the OS or the applications you use.
For example, you could sneak onto a computer, create a new user, give them SSH and sudo permissions, and then clean up afterwards leaving a legitimate looking config in place, and no rootkits - then come back later and do your evil.
Best thing to do is look at what ports have services listening on them, then look at the configuration of all those services and make sure they are all legitimate.  Then look at your firewall configuration and lock down ports that you don't need, both in and outbound.  Then install RKHunter etc to see if some script-kiddie dropped a root kit in there messily.
To be frank, it is probably less work to do what JJ suggested and rebuild than making absolutely sure the computer hasn't been compromised.  It's the data that is valuable, not the OS and config (apart from the man hours in setting that up).
You'll never be sure it wasn't cracked by someone smarter than you.
Answer: The first step should really be rkhunter/chkrootkit, however I've also had good luck in the past with the features that come built into certain package managers, for example 'rpmverify' which will go through all the packages on your system and check that the MD5Sums of the files they included don't differ from the files on disk.
Core binaries should really have identical MD5s to what's specified in the RPM or DPKG databases, so if they're different you know there's something weird going on.
Answer: The most effective way to determine whether your running system is compromised is to use Second Look.  It will verify the kernel and all the running software in memory to make sure they are consistent with what the distribution vendor shipped.  This is a far better approach than rkhunter, chkrootkit, etc, that look for artifacts of specific known infections.  Second Look makes no assumptions about the integrity of the operating system, so you don't need to have used or installed it before an incident.
(Disclaimer: I am the lead developer of Second Look.)


First steps on a new cleaned dataset

Question: What is the very first thing you do when you get your hands on a new data set (assuming it is cleaned and well structured)? Please share sample code snippets as I am sure this would be extremely helpful for both beginners and experienced.
Comment: This is too broad - please read [What types of questions should I avoid asking?](http://datascience.stackexchange.com/help/dont-ask) in the help center.
Comment: Depends what type of dataset it is and more importantly what do you want to do with it? Ask yourself these questions... i) what is my objective; ii) if i'm going to train a model, will it be supervised or unsupervised?; iii) if supervised, do i have a train-test split? iv) do i have the reference class labels? etc.
Answer: I think this is a reasonable question. Here is what I do:

Peak at the first few rows
Visualize the distribution of the features I care about (histograms)
Visualize the relationship between pairs of features (scatterplots)

I downloaded the abalone dataset from the UCI Machine Learning repository here. Let's say I care about how height and diameter can be used to predict whole weight. For completeness, I've included the step of reading the data from file.
import pandas as pd
import matplotlib.pyplot as plt
import seaborn as sns

data = pd.read_csv("abalone.data", header=False)
data.columns = ["sex", "length", "diameter", "height",
                "whole_weight", "shucked_weight",
                "viscera_weight", "shell_weight", "rings"]

Now we can take a peak at the first few rows:
data.head()

Now, I know that the variables I care about are floating point values and they can be treated as continuous. I want to take a look to see how these three variables are distributed:
fig = plt.figure(figsize=(20,5))
plt.subplot(1, 3, 1)
plt.hist(data['diameter'], normed=True)
plt.title("Diameter")
plt.subplot(1, 3, 2)
plt.hist(data['height'], normed=True)
plt.title("Height")
plt.subplot(1, 3, 3)
plt.hist(data['whole_weight'], normed=True)
plt.title("Whole Weight")
plt.show()

Great! Now, I know that diameter and whole weight are skewed left and right (respectively). I also know that there are some outliers in terms of height (which is why matplotlib gives me extra room to the right of the distribution). Finally, I'd like to see if I can find any visual patterns between my predictors and outcome variable. I use a scatter plot for this:
plt.figure(figsize=(15,5))
plt.subplot(1, 2, 1)
plt.plot(data['diameter'], data['whole_weight'], 'o')
plt.title("Diameter vs. Whole Weight")
plt.ylabel("Whole Weight")
plt.xlabel("Diameter")
plt.subplot(1, 2, 2)
plt.plot(data['height'], data['whole_weight'], 'o')
plt.title("Height vs. Whole Weight")
plt.ylabel("Whole Weight")
plt.xlabel("Height")
plt.show()

Here, I see there is a non-linear relationship between diameter and whole weight and I'm going to have to deal with my height outliers. Now, I'm ready to do some analysis!
Answer: Well, you mention in your question of the data being 'clean and well structured'. In practice, close to 70% of the time is spent in doing these two steps. Of course the first thing you do is to separate the training and test data. Considering the plethora of libraries and tools available irrespective of which technology/language you prefer to use, the next step would be to understand the data via graph plots and drawing useful intuitions specific to your target goal. This would then be followed by various other problem specific methods. As pointed out, the question is very broad and citing code snippets is simply not feasible.
Answer: While @Ben's answer is nice and partially introduces what should be done first with a newly cleaned data set, I feel that the approach is important enough to have its name presented loud and clear: exploratory data analysis (EDA). Therefore, the short answer to your question is that the first step should be EDA.
This suggestion is supported by most researchers, regardless of their knowledge domain or type of study. Here is how the father of EDA presents his thoughts on the subject (Tukey, 1977, p. 1-3; emphasis mine):

Exploratory Data Analysis (EDA) is detective work – numerical
  detective work – or counting detective work – or graphical detective
  work ... unless exploratory data analysis uncovers indications,
  usually quantitative ones, there is likely to be nothing for
  confirmatory data analysis to consider ... [it] can never be the whole
  story, but nothing else can serve as the foundation stone - as the
  first step.

There is an enormous amount of information on approaches, guidelines and procedures for performing EDA. Potential starting points might include EDA page on the NIST's Engineering Statistics Handbook website, EDA pages on the EPA's website, corresponding chapter  from the book "Experimental Design for Behavioral and Social Sciences" and a survey research paper on EDA by Begrens (1997), among many others. It is interesting to note that some sources include less traditional methods into EDA toolset, such as dimensionality reduction and clustering (for example, see the description of this research seminar). While some of the EDA approaches and methods are relatively simple, overall EDA is both art and science, as it combines unstructured (creative) and structured approaches. This aspect is especially important to recognize, as big data exponentially increases complexity of data analyses, including EDA.
References
Behrens, J. T. (1997). Principles and procedures of exploratory data analysis. Psychological Methods, 2(2), 131-160.
Tukey, J. W. (1977). Exploratory Data Analysis. Addison-Wesley.
NOTES: For those interested in the Tukey's classic, it is available on Amazon. Various MOOCs on EDA are also available, for example this one and this one (both are R-focused).
Answer: A post by Donne Martin will give you a good idea of performing data analysis on a dataset to make it a tidy dataset in order to apply machine learning algorithms.
Kaggle Machine Learning Competition: Predicting Titanic Survivors | Jupyter nbviewer
Also if you are a beginner I would definitely recommend
7 Steps to Mastering Machine Learning With Python | KDnuggets.

First steps on a new cleaned dataset


Multiple sensors on one GPIO

Question: I would like to know is it possible to connect for example: thermometer and pressure sensor to one GPIO?
Answer: The answer is: it depends.
If you are dealing with 1-wire bus sensors, which are digital and can understand individual addressing, it is perfectly possible.
Just stack up to 10 of them in the 1-wire GPIO pin (check adafruit's tutorial on how to connect one and repeat for up to 10 in the same pin). This works, I have a configuration with 2 DS18B20 working perfectly.
The i2c protocol is also addressed, and should support connecting more than one device likewise. I haven't personally tested the implementation used on the Pi to be sure.
Other sensors/protocols might not understand addressing and just might not work.
Comment: I2C certainly works on the Pi.  It needs two gpios, for data and clock (and a ground connection).  You can connect as many devices as can be uniquely addressed (112 for the Pi's 7 bit addressing).  I've only had four connected at once.

Multiple sensors on one GPIO


How to duplicate a form field in WFFM?

Question: My WFFM form uses the same drop list of manual values 62 times. I'd much prefer to just create it once, and copy it the other 61 times, rather than building out the same drop list over and over again. Is there any way copy or duplicate an existing drop list in WFFM?
Comment: If I understand your question correctly, you have same set of dropdown values which you want to use on multiple WFFM forms and don't want to create the same field values for each WFFM forms specifically rather want to create it once and want to re-use for all the other forms. Is that correct ?
Comment: No - I have the same set of dropdown values that I want to use over and over again on the exact same form. I know it sounds like a strange thing to want, but it makes sense in the context of this form.
Comment: Nevermind in that case as well, please refer the answer I posted below. Its always a best practice to use a droplist populating Sitecore Content Items rather creating the same droplist multiple times manually.
Answer: Rather creating a manual drop list field multiple times, I would prefer to create an item repository somewhere in the content tree (Global location is preferable) with all possible Drop List values and on the drop list field in WFFM Form map the Set Item by value to Selecting Sitecore Items rather Manual entering names. Thus you can reuse the same set of drop list values for any form you create.

Create the set of possible values in drop down using specific user defined template:

Create a form and define a drop list field on it:

Navigate to 'List' section:

Open the 'Set Items By' drop list:

Select the 'Selecting Sitecore Items':

Click on Browse and choose the repository path from the content tree:

It will populate all the item created under that repository. You can differentiate between 'Value' and 'Text' property here:

Once done, all the items created under the repository will be available on your form. Which you can either use on multiple forms or multiple times on same form:
Note: Make sure all the drop list values are published to web database.

Edit 1: To duplicate a form field.
You can navigate to the /sitecore/system/Modules/Web Forms for Marketers/<<<Your Form Path>>> and duplicate the fields listed under that form:

Disclaimer: I never practically tested this approach but since form
  field is also an Sitecore Item hence I am assuming it should work.
Comment: That would get me halfway there, if I do this I won't have to create the list of values over and over which is great. However, because I need that form field many times on the exact same form, I'd still have to click "Add field," chose the drop list type, choose my CSS class from the menu, and finally navigate through the sitecore tree to choose my drop list values. And then repeat 61 times -- still a lot of manual effort! Sounds like there is no way to duplicate a WFFM form field within the same form though.
Comment: Updated my answer by adding steps to duplicate a Form Field.
Comment: Yes! Duplicating a form field like that is exactly what I needed. For others who are using SXA like I am, the path to find the form is slightly different: /sitecore/Content///Data/Forms/, after that the step to right click and duplicate is the same. Also, I created my possible drop list values inside that same "Forms" item as well, since my SXA site doesn't have a Global folder and the Data folder seems to be where global content is stored in SXA.
Comment: For an added bonus you could also use the Sitecore Powershell module to do your duplication - especially if your fields are going to be named "Inquiry type (1-n)" or something like that.

How to duplicate a form field in WFFM?


When you make a virtual PC of a certain one, can you use the programs that it contains?

Question: I was wondering if is possible to use whatever programs that I have in a PC by doing a virtual machine of it, and running it in another PC without installing them again.
Answer: You can make an image of your hard drive and convert it into a virtual disk which can then be used to run a virtual machine.
See: http://www.makeuseof.com/tag/create-a-virtual-machine-image-of-your-existing-hard-drive-windows/
Answer: That is the point of virtualizing a system. You can use Microsofts disk2vhd utility to convert existing Windows installs into a vhd file which can then be imported into your hypervisor like VirtualPC, Virtualbox, VMWare, etc.
Answer: Have a look at Paragons solution Go Virtual.  It's very easy to use.  And supports multiple virtualization platforms.  Depending on your budget you could also have a look at Paragon Virtualization Manager Corporate 2010.  It's not free but it works very nicely.


meaning of infinitely many. Is it same as $\forall$?

Question: As the title stated , what is the meaning of infinitely many ? When we say a set contains  infinitely many elements, does this mean we cannot finish counting all the elements in the set ? Does infinitely many same as $\forall$ ?
Answer: No, $\forall$ means that for all elements. Infinitely many just means there are infinitely many elements with a certain property.
For example $A=\{p\in\mathbb N\mid p\text{ is a prime and } p\equiv 1\pmod 4\}$ contains infinitely many prime numbers, but it is not true that all the prime numbers are in $A$, or that all the natural numbers are in $A$. Therefore the property defining $A$ holds for infinitely many elements, but hardly for all of them.
Another example would be $\mathbb R$ with the $\leq$ relation and $0$. For infinitely many numbers it holds that $0\leq x$, but hardly $\forall x.0\leq x$.
Answer: $\forall$ is just a shorthand way of saying "for all". It can be used for infinite or finite sets.
For example:
$$\forall x \in \{ 1, 2, 3\},\ x > 0.$$
"Infinitely many" means that there are not finitely many. In other words, "infinitely many" means that there does not exist some real integer $n$ such that you can describe the objects with a set of cardinality (size) $n$.
There are different types of infinitely many: countably many, which means the infinite set can be counted with a bijection to the integers, and uncountably many, which means the infinite set cannot be counted with a bijection to the integers.
Answer: Infinitely many means that you can find a subset and a bijection with $\mathbb{N}$, that is, you have an infinite elements.
Comment: Aren't there infinitely many real numbers?
Comment: @ℝⁿ. Well, sometimes there are only countably many of them if you ask certain cranks. :-) (Also, change that username back already!)
Comment: Yes, but this is another infinite 'greater than' the first one. You know, that notion of $\aleph$.
Comment: @Asaf: "Display name may only be changed once every 30 days; you may change again on Feb 28 at 0:06" My hands are tied!
Answer: You have to understand this from basic definitions.
Firstly, a set A is said to be infinite if it is "not finite" OR equivalently, there exists a bijection from A to a strict subset of itself. Additionally, we don't say a set contains infinitely many elements, instead we say it is infinite. We use the phrase "infinitely many" in the following way for example:
"A has infinitely many elements satisfying property P"
This in NOT synonymous as $\forall$ as the other answers have answered.
So what does finite mean? A set A is finite if $\exists K \in \mathbb{N}$ such that there is a bijection from A to $\{1,2,..K \}$


Shooting on the beach: is it dangerous for my equipment?

Question: To what extent it can be harmful for a camera and lens to take shots when being on the beach? I mean the influence of beach sand on the gear. What precautions should be taken to prevent any bad effects of it?
Answer: The combination of sand and wind that is common on a beach can be harmful.
The sand can get into the camera and damage the lenses and sensors.
There are quite a few different approaches:

Don't take a camera to the beach I think this is far too extreme, without risk there is no reward
Don't take an expensive camera to the beach plausible, but still a little much for me
Take your camera but take good care of it

make sure to keep it covered as much as possible (gallon sized zip-locks are your friend) and clean it as good as you can when leaving.  When cleaning, try to blow any sand/dust off before you wipe it off (think about sandpaper).
avoid changing lenses while on the beach, if you need to change lenses, go inside a car/building/somewhere secluded to avoid letting grit inside the body.
use a uv filter to protect the lens (some will argue with this, but a damaged filter is much cheaper than a damaged lens)
Do Not place your camera in the sand (also avoid touching it with sandy hands)
Avoid putting a camera bag down in the sand, because once the sand is in the bag, it will be hard to get it out.

Don't worry about it, just go ahead and take some good pictures. This is the photojournalist approach... if you get good enough shots, you can pay to repair/buy new equipment.

I think option 3 is the best, do what you can to take care of the equipment, use a single lens if possible, and take some good pictures.
Answer: Sand is not the only issue, there is also saltwater is the air. Even if you keep your camera dry, the environment at the beach is more corrosive than some distance inland. (Cars owned by those who live near the beach show more corrosion than those not near the beach.) This isn't as big an issue as sand, and is far less an issue the more plastic the camera body.
I would always give the externals of the camera a good wipe-down when returning from beach shooting.
Answer: Well, a lot of it depends on the camera and lens(es) involved. A lot of point and shoots designed for rugged use are perfectly fine there. For dSLR cameras, it will depend. For most brands (if not all of them), the top end of their gear is often dust and weather sealed and so the camera, itself, is probably well defended. However, if the lens is not dust and weather sealed, you can run into some issues with that. Net effect, if both camera and lens has weather sealing, knock yourself out! If they aren't, then chills42's option #3 is a prudent way to go.
Answer: Take the risk seriously.  Beaches not only have sand, they tend to be windy.  Within just a minute of getting your camera out you can have sand on your lens or somewhere else.  This is a good time to have a UV filter on your lens.


Is it possible to calculate or mathematically prove if a game is balanced / fair?

Question: This question is not focussed on video games but games in general. I went to a boardgame trade fair yesterday and asked myself if there is a way to calculate the fairness of a game. Sure, some of them require a good portion of luck, but it might be possible to calculate if some character is overpowered. Especially in role-playing games and trading card games. How, for example, can the creators of "Magic: The Gathering" make sure that there isn't the "one card that beats them all", given the impressive number of available cards?
Comment: MtG creators make lots of playtests, and when even that doesn't help (sometimes there are combos allowing you to win in first turn), they [ban cards from tournaments](http://tvtropes.org/pmwiki/pmwiki.php/GameBreaker/MagicTheGathering) (warning, TVTropes).
Comment: As a side note, there are games where playing strictly to win is making the game less fun for *everyone*. [Once Upon a Time](http://en.wikipedia.org/wiki/Once_Upon_a_Time_%28game%29) is one such particularly notable example, but in general the whole "social" category of games is full of them.
Comment: Well, run a bunch of simulations/gather data. That is how they do balancing in StarCraft 2... They measure which units are used most, and which race wins the most. Data collection is the key for complex games, and statistics is just as good as mathematics. Even better I'd say, since you'll capture psychological effects as well. That is why there are not nearly as many mathematicians playing poker than you'll expect.
Comment: Some of the best German board games are developed by mathematicians (e.g. [Reiner Knizia](http://en.wikipedia.org/wiki/Reiner_Knizia)) who specialise in game theory, and it shows. Knizia's games in particular are *extremely* well balanced.
Comment: So far, the MTG creators failed frequently at this and released cards which turned out to be far overpowered (often because of interactions with other cards they didn't consider), so they had to be banned in official tournament play.
Answer: Yes, it's theoretically possible - that's a good part of the game theory which deals with this subject.
However, it's only rarely practical, and even then mostly just for games which don't involve a randomiser (Chess, Reversi, Go and so on). Combinatorial explosion ensures that the theoretical time needed for such proofs for more complex games like Magic the Gathering can easily be several orders of magnitude longer than the current age of the universe.
In the end, for any non-trivial game you'll likely have to abandon the notion of proving balance or fairness of a game and instead go with a combination of common sense, designer instincts, game system reuse and throughout testing.
Comment: Add to this that a game that is *proven* to be fair is not necessarily *perceived* to be fair by its players. And it's perception that really matters most of the time.
Comment: Actually, even if the game is total random, it can be proven to be fair.  For example, flip a coin: heads I win, tails you win.  The mathematical definition of fairness is E(ProfitOrLoss)=0 over the long run.  Joe Wreschnig above has the most accurate comment here.
Comment: Also neither Chess nor Go has been "proven" to be fair.  In Chess, [it is not known](http://en.wikipedia.org/wiki/First-move_advantage_in_chess) whether or not the white player has an advantage.  In Go, different countries have different [komi](http://en.wikipedia.org/wiki/Komidashi), so Go **cannot** be fair in, at most, all but one of them.
Comment: @BlueRaja: Game theory absolutely gives us tools for analyzing fairness in games, e.g. the Nash equilibrium. If the payoffs are equal, then the game is fair. If the payoffs are unequal, the game is not fair. The catch is that not all games have a unique Nash equilibrium, and most interesting games don't have a computationally tractable one even if they have one (and that's probably by definition of "interesting"). But game theory absolutely covers this domain.
Comment: @BlueRaja-DannyPflughoeft: re different Komi in Go: Remember that the scoring is slightly different also, so a comparison is only meaningful when considering both effects.
Comment: "mostly just for games which don't involve a randomiser" - couldn't you exhaustively check all possible outputs of the randomizer in addition to checking all legal moves?
Comment: @BlueRaja - Danny Pflughoeft: Game theory is used to reason about games, including to prove whether a game is "fair" or not, for any given definition of "fair". Chess and Go were just examples - since they're easy enough to understand the rules, but also hard enough so they show how combinatorial explosion works.
Answer: Short answer: Any game with a finite, even if undefined, number of available moves thus has a finite number of possible games. Any game with a finite "game tree complexity" can theoretically have all possible games analyzed to determine if the number of games in which each player would win is equal.
Simply put: if Player 1 wins exactly half of all possible plays of a game, the game is balanced. If this is not true, the game is biased towards one player or the other.
However, this simple rule can be quite infeasible to put in practice. Go, for instance, has a game-tree-complexity on the order of 10^170 possible games, more than the number of atoms thought to exist in the known universe. It is thought to be impossible to compile an exhaustive game tree. However, the library of games played and recorded is in the millions, and suggest that the game has a "first-move advantage" (which is typically mitigated with 1.5 points of "komi" given to White).
Contrasting that, even given large overall game-tree-complexities, all M,N,K games (a grid board of M width, N height, in which the object is for a player to create a row of K pieces by placing and never moving/removing them) are solved, because there is a shortcut; entire "branches" of the game tree can be identified as always causing one player or the other to lose. The remaining branches follow a pattern that can be identified. Tic-Tac-Toe is the obvious example; in addition to having only 300,000-ish possible games, there are only 16 in which one player or the other doesn't make a move that will obviously let the other player win on the next move. So, the game-tree starts small and gets smaller when you consider the games the players are actually likely to make.
In games with an element of luck, the game-tree complexity is inflated beyond the number of decisions available to each player. Because the game is no longer played with "perfect information", as it is in chess, checkers, Go, Othello, etc, it is possible for a player who has played perfectly given the known information at the time to still lose to the game's random element. These games have no "solution"; however, there is usually still a finite game tree and so theoretically games could still be analyzed exhaustively. This is still usually not feasible; instead games involving probability are analyzed probabilistically to identify the "best-bet" strategies, and if these strategies are shown to favor the player that uses them, regardless of the strategy used by any other player (including the same strategy), the game can be shown to have bias.
In general, the following rule applies: if the design of the game inherently leads to inequality in one or more of the following, the game has a bias:

Number of total moves for each player
Number of moves available at any given time that will allow at least one more move for that player
Starting strength of players' forces
Access to finite resources or areas of identified strategic significance

Now, the game's design may introduce one inequality but attempt to compensate with another. Or, the game's design may allow for randomness in areas that may produce bias, meaning one game might be biased while another is fairer (games with random starting boards can exhibit this). In these cases only empirical analysis of games between players of roughly equal strength over the long-term can demonstrate any bias.
For more discussion of bias in board games, try the forums of http://www.geekdo.com; there have been several discussions of demonstrated bias in games, and how to avoid said bias in game development in general.
Answer: I guess there is no pre-made mathematical formula to evaluate how fair a game is because of how every game is so different and complex.
You can't really compare different game parameters and make up some sort of power score of how good a character is (unless your game is very simple) because they all affect your gameplay differently and depend on how they are implemented (e.g. how can you evaluate how strength relates to vitality? How do you give a numerical value to a character's special attack?).
You have to test your game. A lot. Play your game by yourself and make others play it and store the battle/game results in a file in order to make statistics and evaluate how often certain characters win, under what circumstances, etc. Then, make sure you implement some way to check replays or analyse gameplay in order to see why such a character is overpowered and apply the changes accordingly.
Really, you have no other option than testing. That's one of the reasons why betas exist (e.g. Starcraft2 as a beta gave Blizzard the opportunity to balance the 3 races based on the game results).
To sum up, play your game, and make others play it (starting a beta is an option). See why the game is unbalanced through replays or automated analysis and change what needs to be changed accordingly. That's the only way you'll approach fairness.
Comment: To whoever downvoted, why so?
Comment: +1 for *test your game*.  Beta testing is important in video games and board games, the more people testing your game, the more likely that someone will find that broken card or spell that ruins everything.
Comment: Testing is spot on. Introduce a new card? Run it through a large scale simulation of randomized decks to see how often it was part of the winning deck. If a majority of the winning plays were related to the new card, then you should tone it down and try again.
Answer: To be able to prove a game was balanced or fair, you'd have to define what balanced or fair means first. These are rather vague terms that can encompass a range of things, for example game 'balance' is often taken to mean:

each of several different sides has the same chance to win
progression through the game gets consistently more challenging
decisions made within the game offer identical cost/payoff ratios in some/most/all cases

And so on.
In general I am a fan of mathematically proving things like this, but to prove anything through logic or testing you first need to define it clearly. Some aspects of balance are easy to test through mathematics if you're able to understand your game rules properly. Others are much harder to judge without simply conducting empirical tests. The main problem is that most game designers don't truly understand the mechanics of their game, since they usually end up merging game rules into a surrounding simulation, and the latter is very hard to model accurately.
Answer: Theoreticaly it is possible, but for most games it is extremely difficult so it can be considered impossible.
One approach:
Convert game into normal form.
Game in normal form is Set of strategies for each player and function that says how good result is when for given combination of choices.
Random factor can be modeled as another player.
Then we can look for dominant/dominated strategies (things to ALWAYS do and things to NEVER do).
Game is at lest somehow interesting, if it does not contain dominant strategies.
Then we can look at what each player can guarantee for himself.
for each of "MY" choice, look at worst possible outcome and take choice that have this best.
If it differs a lot between players, there is somthing rotten in game.
There are other things to look at (dominant mixed strategy (choosing each choice with some probublity), nash equilibriums (combinations that once all players know others will do, are localy best for everyone)).
But the first step is so extremely complicated for most games, so it's usualy not so usefull.
But it can be used if you can absract complicated details away/ replace strategies with recognizable sets of strategies (eg. initial build orders) and result with some statistical aproximation from actualy played games and it can tell you something about problems in game. I guess that something like this blizard does with SC.
Another form of game is game where players takes turns and know everything others do (chess). There you can try to search for dominat strategy by searching state tree of game (and it usualy is HUGE, so again, too complicated to use).
And lot of games are without total knowladge and it complicates things a lot.
Another approach, look at things in game and try to compare them.
Another approach: For team combat (esp. with large ammounts participants) you can try to use force on force simulation (I never used it, and it requires high math (diferential equations) and hard work to convert game into aproprite model).
So my conclusion, lot of things can be done to balance subsystems of game, and when game is out (and during betatest), lot can be done by analyzing results, but unless you make everything same, its almost imposible to prove game is balanced.
PS:
You can mask sameness by replacing one attribute by multiple that together can be used to compute initial attribute, and by making everything much more random, so players don't see that sameness (
Beware its easy to make mistake in doing so (eg fast small attacks vs big slow attacks),
beacuse 18 throws by d6 -18 gives results 0-90,
        10 throws by d10-10 gives results 0-90
         1 throw  by d91-1  gives results 0-90
but all of them have different distributions.
PS2: One wise man said, that actual balance is not important, Percieved balance is.
Comment: The dominant strategy concept is very important. The existence of a dominant strategy in any situation implies an inherent unfairness, although usually that just brings about redundancy in the design rather than a balance problem as such. But a designer needs to be able to avoid dominant strategies in order to give every element a chance of having a clear purpose.
Comment: One thing I forgot: Existance of dominant strategy does not have to be problem, as long as its realy hard to execute it, even if player KNOW it. Simplistic example, headshoting is dominant strategy in FPS, but lot of players go for center of mass because its easier to hit, but optimal bot would go for headshot always.
Answer: A lot of good answers about getting a mathematically correct answer, but I'll try a different angle: if your code allows for it, you could simulate a very large number of games and then check if there is a strategy (or strategies) that win too often.
You might be familiar with Monte-Carlo simulations or genetic algorithms. The idea here related. You need an AI to play the game and some key measurement. You let the AI go at each other in a large tournament, often enough, with different starting variables and you measure the results.
I've always wanted to try an approach like that to balances classes/weapons, it would be a ton of fun.
Answer: From a theory of computation perspective, it sounds like answering this is not possible in general. It's asking a question about a property of a program and Rice's Theorem may apply. My assumption is that game refers to a program written in a Turing Complete language like c++. I'm also assuming that to calculate or prove whether a game is fair means there exists a c++ program that reads a c++ program (the game program) and terminates in a finite amount of time for all possible inputs,  with only two outputs, fair or unfair.
A quick search shows it is possible to have a deterministic yet undecidable game, see slide 7 here and from the International Journal of Game Theory: Some undecidable determined games:
"Computing machines using algorithms play games and even learn to play games. However, the inherent finiteness properties of algorithms impose limitations on the game playing abilities of machines. M. Rabin illustrated this limitation in 1957 by constructing a two-person win-lose game with decidable rules but no computable winning strategies."
The human brain is apparently more "powerful" than computers because we can gain and apply past knowledge and sometimes appear to contradict results like the Halting problem by finding infinite loops in programs. But how we do this is not well known and can't be written precisely and unambiguously in an algorithm.
Answer: I really wanted to comment on Martin Sojka's answer, but I don't have the reputation.  He is correct that Game Theory includes calculating the fairness of a game (for example, it's an open question if in a chess game where both white and black played perfectly whether it would be a tie).
For MtG it could very well be that it's completely infeasible to calculate whether it's fair, but no one has proven mathematically that the computation would be infeasible.
It might be trivially possible to prove it's fair - if it's random who goes first and everyone plays by the same rules then it's fair.  It might be that whoever goes first always wins, but if who goes first is decided fairly then the game is fair.
Comment: Remove 109 characters and I will convert this to a comment for you.
Answer: What is meant by "fair" is vague, let me explain :
Consider the game Rock-paper-cissors (http://en.wikipedia.org/wiki/Rock-paper-scissors) : according to you it is fair, I suppose (according to me as well).
Now, let's consider the game : Rock-paper-cissors-well where the well beats the rock and the paper and the well loses against the paper. Unbalanced, right ? The well seems pretty overpowered : it beats two weapons and loses against one.
But one could say that it is not overpowered at all : because if you know that your opponent is more likely to use the well because it beats two weapons, you can just act by picking the paper more often.
So there is an answer to the potential overpowered well : just choose more often the paper. But then you know that your opponent may know that and may use the paper quite often, so you think you should use the cissors more often. Etc.
Not really overpowered, just a different game with different rules.
I would recommend reading about game theory and especially games with imperfect information (http://en.wikipedia.org/wiki/Game_theory).
Comment: No matter what combination of items are involved, any Rock-Paper-Scissors variant is obviously fair because both players are equal. In most board games, one player moves first.
Comment: -1. Whether it's fair or not can be known or unknown (and if unknown, feasible to know or infeasible to know), but game theory gives us plenty of tools to define "fair" without vagueness.
Comment: How, for example, can the creators of "The Gathering" make sure that there isn't the "one card that beats them all" -> I was trying to highlight this sentence and show to the author that his conception of "fairness" is not right. Otherwise, for instance, in a game like Magic, people don't usually have the same cards as their opponent so even though people start at the same time (I don't know actually), it may not be fair. And the game Rock-paper-cissors analogy may not be the best to consider but it explains my point.
Comment: @JohnCastle This is not the place to discuss OP's evaluation of fair, since that would be a discussion and this is not a discussion board (use chat for that). The exception would be if your post answers the question and discusses the OP's conception of fairness as part of that.
Comment: @JonathanHobbs, How can you prove fairness if it is not correctly defined ? It is true that my post is not really an answer - I should have posted just under the main post, I didn't realize - but I think it is important to define fairness before answering the question.
Comment: @JohnCastle The problem is mainly that you did not go on to answer the question, and that gamer culture's already amassed a lot of criteria for what's fair: both players should have an equal chance of winning (given equal skill), there shouldn't be BS moves like instant wins or unbreakable combos, etc. Above all else, trust human interpretation (mathematical proof is meaningless when everyone's crying that your game is imbalanced).
Comment: @JohnCastle Furthermore this post only demonstrates that there are bad ways to evaluate fairness that can lead you to false conclusions... and then you don't go anywhere with that. We're left thinking "ok, but so what?"


How is the holy grail war from Fate/ Stay night kept a secret?

Question: I might have missed the explanation while reading the visual novel but if the magic and all that kinda stuff are kept a secret from the public, then how exactly do you explain the huge glaring flashes of light and the huge amount of noise that comes from the fight between the servants? Is it something to do with the Magic Association/ The Church? I don't actually remember any instances in the the visual novel other than the start of the series with Shirou getting stabbed by Lancer where any witnesses were killed. Not to mention the other shenanigans like Rider summoning his chariot.
Comment: I expect it's something like the "closed space" from *Haruhi Suzumiya* - some kind of pocket dimension where the battles can take place without anyone seeing them - but I'm really not familiar with the Fateverse lore, so that's honestly just a guess and not worth posting as an answer.
Comment: @F1Krazy The Fate concept would be that of bounded fields, but they are rarely invoked in FSN and usually cover very limited areas.  Even servants can't really create a bounded field larger than a high school, and modern mages are basically limited to a workshop.
Answer: From the author Kinoko Nasu himself:

The Holy Grail War is unknown to the general population, but to what extent is it hidden from normal people? Are the Church people (supervisors) manipulating the media and police (or even the governmental level) to cover it up?
A: The Church manipulates information, while the Magic Association handles the media. Also, the Association has the Einzbern cover the cost of any collateral damage.

Fate/complete material III: World material - FAQ with Nasu: Holy Grail War, p.131
Eyewitnesses can be dealt with by manipulating their memories.
Comment: *"Eyewitnesses can be dealt with by manipulating their memories."* or strait up killed, lets not forget that we see in *Fate/Zero* the Magic Association sent a team out to the island Kiritsugu and his father live on and killed everyone when trying to cover up Kiritsugu's father's experiments (and not just the Dead Apostles that were created)


How can I run multiple obfuscated services on a machine?

Question: I would like to add an OpenVPN service (for personal use) to a machine I already have an obfuscated Tor bridge running on (for shared use).  I would like the option to access this VPN through obfsproxy, while still allowing for Tor to have its own managed obfsproxy (both running obfs3).
Is this a problem?  Do I simply fire up a new, non-managed obfsproxy instance for the VPN?
Comment: I would suspect it's just that easy. Have you tried it?
Answer: As long as each obfsproxy instance binds a unique port, you can have as many of them as you have the resources to run.


Can this 7% annual interest penalty on NJ security deposit be applied after the lease has ended?

Question: Below is the penalty to which my question refers.

The landlord NEVER gave info on where the deposit was held (at the
outset or annually) as is required by law.
The landlord also changed the account where the deposit was held over
the time in question and was required by law to notify tenant of the
change but never did.
Tenant asked landlord (in writing) for dated proof that both of these
things were complied with as the law dictates and landlord could not
provide.

Can/Does this apply after the lease has ended? Meaning, can the 7% be collected along with the return of the security deposit?
Since it is an annual 7% penalty, if the lease was 5 years is the penalty added for each year? And if so, should it compound? Or does this not apply at all because it can only be applied to rent and is not owed to the client otherwise?
PENALTY Notice of Deposit of Security Funds
Landlords are required to give tenants a statement in writing including the name and address of the investment company, bank or savings and loan association along with the type of account, current rate of interest and amount deposited within 30 days of receipt of a security deposit. This notice may appear in the lease. The landlord must notify tenants within 30 days of transferring the security deposit money to a new landlord or moving the security deposit to another account or bank. If notification is not given or if the security is not deposited or invested in accordance with this law, the tenant has the right to require that the security deposit, plus 7 % per year be applied toward any rent due. This request must be made in writing. However, after giving the landlord written notice the tenant must allow the landlord 30 days to comply with the annual interest payment and notice requirements. The 30-day allowance is not required if the landlord failed to properly deposit the initial security deposit money. At no time thereafter, while the tenant occupies the unit, can the current landlord ask for or collect another deposit.
Answer: No
The wording is clear "the tenant has the right to require that ... be applied toward any rent due" - if there is no rent due (i.e. all rent has been paid) then the tenant has no such right.
Interest in legal matters is calculated daily and never compounded (unless a contract provides otherwise).
Comment: Gotcha on the interest being calculated daily. If there is supposed to be 7% interested added annually, would that be on the original deposited amount (ie. $1,000 deposit + 7%= $1,070) for year 1...and then for year 2 is it 7% on $1,070 ($1,144.9) for year two and so on?


What happens to the current color when you successfully challenge a Wild Draw 4?

Question: What happens If you challenge a player who say nominates red with his/her wild draw 4 card and you challenge successfully, then the person who played the card would pick up 4 cards instead of you. My question is, does the colour stay as red in this situation or to the colour just before it was reds?
Comment: Challenge? Nominate? Is this for a variant of Uno?
Comment: Nope, it's in the official rules
Comment: Just looked it up... not that I play Uno often at all, but I think I was taught wrong and have always played wrong; I never heard of the rule that you can't play a Wild Draw 4 unless it's your only option.
Comment: @AndyPandy91 Nominate is a funny word to use because it's not like you are having some kind of political convention.  Dictate would be more like what happens when a wild or wild draw 4 is played.
Answer: If the Wild Draw 4 is challenged the person who played the card must show their hand to the challenger. If there is a card in their hand that they could have played then the player must draw 6 cards. If the person who played the the draw 4 has no cards that they could have played then the challenger must draw 6 cards. Regardless the outcome of the challenge the Wild Draw 4 stays in play and the game is played normally. All of this info can be found in the rulebook that came with the cards.
Comment: Based on https://www.unorules.com/, the player who played Wild Draw 4 may have a card that they could play, they just can't have a card of the same colour as the top card. Also, if they do have a card of the same colour as the top card they have to draw 4; drawing 6 is only for an unsuccessful challenger. That's two mistakes in your answer. Please make sure you read *and quote* rules in your answers. (As to actually answering the question - I don't think it *is* specified that the Wild Draw 4 remains in play and the game continues normally; I think that is interpretation.)
Answer: The person who willfully plays a wild draw 4 card to change the color when they had an obvious card to play, is to discard their hand and go watch TV or something, as they have broken the first rule of playing games: No cheaters.  Uno is not a bluffing game, and cheating is not expected or tolerated.
--But perhaps I'm being a bit sensitive.
That said, we usually just have the miscreant pick up their wild and play the appropriate card, as our rule breakers are normally the younger kids who didn't recognize the valid card to play.
(Edit)
The rules stat that if challenged, and player had a valid card to play, they forfeit their turn.  I don't see any rule addressing what happens to the Wild+Draw 4.  But if a player has to forfeit their turn, I would think that you would continue play and their card was never played. They would need to pick it up, since they can't play any cards.. they forfeited.
Comment: Actually from the rules it looks like this part of Uno IS a bluffing game. "A player holding a Wild Draw Four may choose to bluff and play the card
illegally, but if he/she is caught certain rules apply."
Comment: Ok thanks, but it does not say in the rules that you can pick it up, where or how do you know this?
Comment: I added an edit to my answer.  Sorry.