Filter 2d array?

[memark]

The elements of a 1d array can easily be filtered with ▽ keep

1_2_3_4
▽>2.
[3 4]

How can I do the same for a 2d array?

Things I've tried that don't work

[1_2_3 4_5_6]
▽>2.
Error: Keep amount must be a natural number or list of natural numbers, but its rank is 2

[1_2_3 4_5_6]
≡(▽>2.)
Error: Cannot append arrays of shapes [1 × 1] and [3]

[1_2_3 4_5_6]
>2.
≡▽
Error: Cannot couple arrays with shapes [1] and [3]

[kaikalii]

The problem becomes that the filtered rows may end up being different lengths, so you cannot reform the array normally.
The three main ways of solving this are box, pack, and fill.

• boxing the result of keep on each row wraps each filtered row in a box
• pack does the same, but only if it is necessary
• fill fills in the lengths of each row so that reforming the array works correctly

Here are some examples of how they would be used here.
Notice the difference between using box and using pack on array B.

[memark]

Thank you so much! I keep forgetting about the need to box uneven-sized arrays. (In my mind I still only think about boxing when it comes to strings.) Super helpful!