m1(m2 == 1), but with dimensions of m1 intact?

I have a matrix of 1's and 0'1, m2. I have another matrix with the same dimensions as m2, containing values (i.e., m1). Of these values, I am only interested in those where the corresponding value in m2 is 1. However, as an extra condition, I wish to create m3, which has the same dimensions as m1 and m2, and contains the selected values in the corresponding places, with all other places being NaN. I am stuck on how to do that without looping.

Answer 1

[Stephen23]

Method one:

m3 = m1;
m3(m2~=1) = NaN;

Method two:

m3 = NaN(size(m1));
idx = m2==1;
m3(idx) = m1(idx);

Method three :

m3 = m2./m2.*m1;

[Ulrik William Nash]

Method 3 is very neat. Thank you.