You export the variables c0, c1, ... from your function, but you do not import it in the main function. So replace
a=my_mod_idea(m,n);
by
[c0,c1,c2,c3,c4,c5,c6,c7] = my_mod_idea(m,n)
Note: Your code will run much faster, if you read the file once in the main function and provide wm as input argument to the my_mod_idea function.
The line
bitset(hi(i,k),1,c0);
does not store the results anywhere. I guess you want:
hi(i,k) = bitset(hi(i,k),1,c0);
