Hello,

I would like to converte an index (of a flatten array) to a

multi-dimensions coordinates (of the multi-dimensions version of the

previous flatten array).

Example:

Considering the following 2 dimensions array (3x3):

```
[ [ -, -, - ],
[ *, -, - ],
[ -, -, - ] ]
```

We can see that, the coordinates of the checked case is [0, 1].

Now, if we flat this array, it looks like:

```
[ -, -, -, *, -, -, -, -, - ]
```

Here, we can see the coordinate (or the index) of the checked case is 3.

But how can we do the opposite? I mean, a method looking like:

```
index_to_coordinates([3, 3], 3) # => [0, 1]
```

Thanks!