I have two arrays with the same dimensions, call them A and B, and a third boolean array, C. I want to create an output array, where the values from come from either A or B depending on whether C is true of false. So for example, if A←1 2 3 4 ⋄ B←11 22 33 44 ⋄ C←0 0 1 1, I want the result to be 1 2 33 44`.
@Adám about % at all or that it works on high rank arrays? (i've mentioned % somewhat recently, but i had no clue if i had actually bothered to implement it for high rank)
@Adám I did search dilligently on APL cart, but in a glass-half-empty way: zero triangular etc. But I think it would be nice if this showed on just 'triangular' as every other operation on triangulars seem to do.
Ok, more array gymnastics: given a boolean rank 2 matrix A and Ys Xs, zero all elements on row Ys and col Xs in A, except A[Ys;Xs], and leaving all other elements as is. So given:
@rak1507 It is bug 17228 in the interpreter: When the interpreter needs to call a callback function to print something, it should create a ⎕ORed clone of the item to print and pass that, but instead it does an in-place ⎕ORing and so a side effect of printing with a callback is that the item that was printed changes from being a function to be a ⎕OR.