how to set anti diagonal part of matrix with zero value elements ?

i know that how to set diagonal part of matrix to zero, for that we have a code m=256; n=256; a=ones(m,n); u=triu(a); imshow(u);

but in case of anti diagonal what will be code?

Answer 1

[Nicolai Sanders]

I think this might do what you need.

m=256; n=256; a=ones(m,n); u=flip(triu(a)); imshow(u);

Look at the help page for "flip" to see the options.

[ajeet verma]

thanks for giving me answer but 'flip' is not working instead of this i have tried 'flipud' that give me required result

[Walter Roberson]

flip was new as of r2013b