#include #include #include #include #include double clock_cpu_read() { // returns CPU time used by this process so far struct tms tb; times(&tb); return (double)(tb.tms_utime+tb.tms_stime)/HZ; } void main(int argc, char **argv) { Mat g; // we construct a 2-D array (grid) of doubles // but don't specify yet how big it is int n = argc>1 ? atoi(argv[1]) : 1024; printf("creating %dx%d array\n", n+1, n+1); double t0 = clock_cpu_read(); // start timer g.SetSize(n+1, n+1); // set size of grid g (dynamic alloc) int i, j; for (i=0; i<=n; i++) // zero the array g for (j=0; j<=n; j++) g[i][j] = 0; double t1 = clock_cpu_read(); // stop timer printf("took %g seconds\n", t1-t0); }