#include <jmat.h> void djmata(double n, double m, double *out){ int i,nn,mm,j; mm=(int) m; nn=(int) n; for (i=0;i<n;i++){/*We work by blocs*/ for(j=0;j<m;j++){/*then by column*/ /* * i*mm*nn : advance to the good column * mm*(nn-(i+1)) : take the first element of the column to be 1, when j=0 * j*(mm*nn+1) : advance to the next which must be 1 * */ out[i*mm*mm*nn+(mm*(nn-(i+1))+j*(mm*nn+1))]=1; } } }