I have an array of items like so: `[DateTime, value]`. I want to group the items which satisfy the following conditions:

* A sequence of 3 or more items
* Items contain values which are > 0
* times are sequential (increasing by 1 second)

I want to get the indices of the start and end of the sequences that meet those conditions.

E.g.

```
[ 
[today 10:00:00, 1],
[today 10:00:01, 1],
[today 10:00:02, 1],
[today 10:00:03, 0],
[today 10:00:04, 1],
[today 10:00:05, 1],
[today 10:00:16, 1],
[today 10:00:17, 1],
]

```

Should return:

```
[ [0,2] ]

```

I had a look at [Daru](https://github.com/SciRuby/daru) and [NMatrix](http://sciruby.com/nmatrix/docs/NMatrix.html) but I couldn't figure out how to do sequential comparisons to do what I want. 

Now I've just got a big loop that does a lot of comparisons - is there a better way to do it?