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//------------------------------------------------------------------------------
// GraphBLAS/Demo/Program/simple_demo.c: tests simple_rand and simple_timer
//------------------------------------------------------------------------------
// SuiteSparse:GraphBLAS, Timothy A. Davis, (c) 2017-2020, All Rights Reserved
// http://suitesparse.com See GraphBLAS/Doc/License.txt for license.
//------------------------------------------------------------------------------
/*
A simple test that illustrates the use of simple_rand and simple_tic/toc.
This test does not require ANSI C11, nor GraphBLAS. It only tests the
simple_* Demo functions. The output of this test should look like the
following. The random numbers should be the same. On a Mac OSX system:
time to call simple_tic 1 million times: 0.367798
time to generate 10 million random numbers: 0.10633
first 10 random numbers:
0.513871
0.175726
0.308634
0.534532
0.947630
0.171728
0.702231
0.226417
0.494766
0.124699
The clock_gettime function in Linux is even faster (0.02 seconds to call
simple_tic 1 million times). The random numbers are identical, as desired.
*/
#include "simple_rand.h"
#include "simple_timer.h"
#include <stdio.h>
#include <stdlib.h>
#define LEN 10000000
int main (void)
{
double *x ;
double tic [2], t ;
int i ;
fprintf (stderr, "simple_demo:\n") ;
double n = ((double) LEN) / 1e6 ;
// calloc the space for more accurate timing
x = (double *) calloc (LEN, sizeof (double)) ;
if (x == NULL)
{
fprintf (stderr, "simple_demo: out of memory\n") ;
exit (1) ;
}
// do lots of tics
simple_tic (tic) ;
for (i = 0 ; i < LEN/10 ; i++)
{
double tic2 [2] ;
simple_tic (tic2) ;
}
t = simple_toc (tic) ;
printf ("time to call simple_tic %g million times: %g\n", n/10, t) ;
// generate random numbers
simple_tic (tic) ;
for (i = 0 ; i < LEN ; i++)
{
x [i] = simple_rand_x ( ) ;
}
t = simple_toc (tic) ;
// report the result
printf ("time to generate %g million random numbers: %g\n", n, t) ;
fprintf (stderr, "time to generate %g million random numbers: %g\n\n",
n, t) ;
// these should be the same on any system and any compiler
printf ("first 10 random numbers:\n") ;
for (i = 0 ; i < 10 ; i++)
{
printf ("%12.6f\n", x [i]) ;
}
// generate random uint64_t numbers
double t1 ;
simple_tic (tic) ;
for (i = 0 ; i < LEN ; i++)
{
simple_rand_i ( ) ;
}
t1 = simple_toc (tic) ;
printf ("time to generate %g million random uint64: %g\n", n, t1) ;
fprintf (stderr, "time to generate %g million random uint64: %g\n\n",
n, t1) ;
free (x) ;
}
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