copy element position from one vector to another

Hello everyone,

I'm trying to find a way where i copy the positions of NaN values in a onto the same positions in b. Does anyone has a suggestion what could work?

Thank you!

a=rand(100,1);
a(20:30)=nan;
a(60:80)=nan;

b=rand(100,1);

Answer 1

[KSSV]

a=rand(100,1);
a(20:30)=nan;
a(60:80)=nan;

b=rand(100,1);
b(isnan(a)) = NaN ;