How to replace values less than ...

HOW TO NAME THE VARIABLE BECAUSE IF I WRIGHT IT GIVES ME AN ERROR FOR EXAMPLE e =matrix (matrix<=0)= NaN;

Answer 1

[DGM]

Assuming you have a matrix A and you want to make a copy B which has all nonpositive content replaced with NaN

A=randn(100);
B=A; % make a copy
B(B<=0)=NaN; % replace the values

Trying to do something like

B=A(A<=0)=NaN; 

isn't going to work.

[laith awwad]

Thank you it worked