MATLAB: Find a vector in a big vector

Question

hi! how could i write this:

 %
index=[find(a=2);find(a=4);find(a=6);find(a=8)....find(a=20)]

in a compact manner?

thank you

Answer 1

vals = (2:2:20)';
your_mat = cell2mat(arrayfun(@(x) {find(a==x)},vals,'uniformoutput',false));

And if you don't care about the order:

 vals = (2:2:20)';
 [ia ib] = ismember(a,vals);