conditional array extraction based on control array

I have the following problem:

For example, I have three arrays:

x = [1,2,3,4,5,6,7,8,9,10] and its corresponding y values: y = [21,43,77,54,38,24,99,64,77,33] and also a "control" array: c = [3,5,7,9]

Is it possible to somehow extract from 'y' only those entries that have corresponding entries in both 'x' and 'c' array and put them in for example 'z'? In this case z = [77,38,99,77]

Thanks.

Answer 1

[Cedric]

For the second part of the question:

 z = y(c) ;

What do you mean by "corresponding entries in x "? How do you define correspondence if x and y don't have the same number of elements?

Answer 2

[Ivan]

I mean that only if entry exists in both 'x' and 'c' for instance '3' does, then to copy in this case 77 form 'y' into 'z'.

[Cedric]

Ok, so you can achieve that with intersect, as mentioned by Eric, below.

Answer 3

[Eric Sampson]

If I understand your question correctly, try this:

z=y(intersect(x,c));