Replacing Values of one matrix with another

I'm trying to replace one Matrix values with NaNs from another vector in the same locations, but I keep getting getting the reverse. It puts NaNs where values are supposed and keeps the values where NaNs are supposed to show. My code is:

isn_east = find(~isnan(east));

VV=Reference_E;

>> VV(isn_east)=NaN;

east is the matrix where the NaNs are located. VV is matrix the i'm tryig to put NaNs in.

Answer 1

[Stephen23]

isn_east = isnan(east);

or simply:

VV = Reference_E;
VV(isnan(east)) = NaN;

[Kayla Washington]

Thank you!