Numpy where functionality for Julia code?

Question

I read the answer to "What is Julia equivalent of numpy's where function?", but do not yet see how the answer (ifelse) gives the user all the functionality of numpy.where. I have posted example code below:

    A = [0.0 0.9 0.0 0.99 0.0]

    a = 1:length(A)

    #-v- produces [0 1.0 0 1.0 0] as expected, but how to get the index values?
    b = ifelse.(A .- 1.0 .> -1.0, 1.0, 0 )
    #-^- how to get the array [0.9 0.99]? How to remove all zeros from an array?

Any workarounds other than using for loops would be appreciated.

Answer 1

Potentially avoiding allocating the masking array would be faster, so filter(x -> x>0, A)