find should return linear indices

[ghost]

Find works differently than in MATLAB, because if you find on a matrix, you get a bunch of index-pairs. But this is kind of annoying when you're dealing with nx1 or 1xn matrices, then you're often throwing in find(v)[1] and find(v)[2] to get things to work. To understand, type a = [1,0,1]; and then findnd(a), findnd(a'), findnd(a").

Furthermore, in MATLAB you're often doing A1(logical(A2)) or vec1(logical(vec2)), there should be canonical ways of doing these things in Julia.

These things should be considered along with whatever Julia's solution is to ind2sub and sub2ind (from MATLAB). If A is a matrix of 1's and 0's, [x,y] = ind2sub(size(A),find(A)) does in MATLAB what find currently does in Julia.

[ViralBShah]

Unfortunately, this is not easy to implement, because matlab does things differently based on the number of output arguments. We can use a different name like find1, findn etc, but would be nice to hear from Jeff on how to do this.

That said, Julia does have ind2sub and sub2ind, but I agree that find/ind2sub/sub2ind need to all work coherently.

[JeffBezanson]

It seems like the simplest thing is for find to return linear indices, and you can use ind2sub if you need something else.

[ViralBShah]

In most cases when I use find, I don't want the linear indices! Guess its a matter of taste.

[ViralBShah]

This is yet another of those nargout cases.