Pseudo-random numbers generation

Functions
int DSPL_API	randb (double *x, int n, random_t *prnd)
	Binary unipolar [0, 1] pseudorandom vector. More...
int DSPL_API	randb2 (double *x, int n, random_t *prnd)
	Binary bipolar [-1, 1] pseudorandom vector. More...
int DSPL_API	random_init (random_t *prnd, int type, void *seed)
	Pseudorandom numbers generators initialization. More...

Detailed Description

This group describes the functions of the pseudo-random numbers generation by different algorithms.

Function Documentation

randb()

int randb	(	double *	x,
		int	n,
		random_t *	prnd
	)

Binary unipolar [0, 1] pseudorandom vector.

---

The function generates a unipolar pseudo-random vector, each element of which takes an equally probable value of 0 or 1

Parameters

[in,out]	x	Pointer to the unipolar pseudo-random vector. Vector size is [n x 1]. Memory must be allocated.
[in]	n	Size of vector x.
[in]	prnd	Pointer to the random_t structure. The structure must be pre-filled with the random_init function. This pointer can be NULL, then it will be used built-in pseudorandom generator defined by the C language standard. However, this mode is not recommended, for example in cryptography and other tasks. There is no guarantee of the quality of the pseudorandom numbers produced if the prnd parameter is set toNULL.

Returns

RES_OK — if pseudorandom vector is calculated successfully.
Else code error.

Example:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "dspl.h"
 
#define N  100
 
int main(int argc, char* argv[])
{
    void* hdspl;            /* DSPL handle        */
    void* hplot;            /* GNUPLOT handles    */
    random_t rnd = {0};     /* random structure   */
    hdspl = dspl_load();    /* Load DSPL function */
 
    double x[N];
    int err;
 
    err = random_init(&rnd, RAND_TYPE_MRG32K3A, NULL);
    if(err != RES_OK)
        goto exit_label;
 
    err = randb(x, N, &rnd);
    if(err != RES_OK)
        goto exit_label;
 
    writetxt(x, NULL, N, "dat/randb_mrg32k3a.txt");
 
    err = randb2(x, N, &rnd);
    if(err != RES_OK)
        goto exit_label;
 
    writetxt(x, NULL, N, "dat/randb2_mrg32k3a.txt");
 
    /**************************************************************************/
    /* plotting by GNUPLOT                                                    */
    /**************************************************************************/
    /* Create window plot */
    err = gnuplot_create(argc, argv, 820, 320, "img/randb_test.png", &hplot);
    if(err != RES_OK)
        goto exit_label;
 
    gnuplot_cmd(hplot, "set xlabel 'x'");
    gnuplot_cmd(hplot, "set ylabel 'y'");
    gnuplot_cmd(hplot, "unset key");
    gnuplot_cmd(hplot, "set yrange[-1.2:1.2]");
    gnuplot_cmd(hplot, "set title 'randb, randb2'");
    gnuplot_cmd(hplot, "plot 'dat/randb_mrg32k3a.txt' with lines, \\");
    gnuplot_cmd(hplot, "     'dat/randb2_mrg32k3a.txt' with lines");
 
exit_label:
    printf("Error code: %x\n", err);
    if(hplot)
        gnuplot_close(hplot);
 
    /* free dspl handle */
    dspl_free(hdspl);
    return 0;
}
 

Program genrates unipolar [0, 1] and bipolar[-1, 1] pseudorandom binary vectors.

As a result of the program run, you can see the graph:

Author

Sergey Bakhurin. www.dsplib.org

Definition at line 118 of file randb.c.

randb2()

int randb2	(	double *	x,
		int	n,
		random_t *	prnd
	)

Binary bipolar [-1, 1] pseudorandom vector.

---

The function generates a unipolar pseudo-random vector, each element of which takes an equally probable value of -1 or 1

Parameters

[in,out]	x	Pointer to the bipolar pseudorandom vector. Vector size is [n x 1]. Memory must be allocated.
[in]	n	Size of vector x.
[in]	prnd	Pointer to the random_t structure. The structure must be pre-filled with the random_init function. This pointer can be NULL, then it will be used built-in pseudorandom generator defined by the C language standard. However, this mode is not recommended, for example in cryptography and other tasks. There is no guarantee of the quality of the pseudorandom numbers produced if the prnd parameter is set toNULL.

Returns

RES_OK — if pseudorandom vector is calculated successfully.
Else code error.

Example:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "dspl.h"
 
#define N  100
 
int main(int argc, char* argv[])
{
    void* hdspl;            /* DSPL handle        */
    void* hplot;            /* GNUPLOT handles    */
    random_t rnd = {0};     /* random structure   */
    hdspl = dspl_load();    /* Load DSPL function */
 
    double x[N];
    int err;
 
    err = random_init(&rnd, RAND_TYPE_MRG32K3A, NULL);
    if(err != RES_OK)
        goto exit_label;
 
    err = randb(x, N, &rnd);
    if(err != RES_OK)
        goto exit_label;
 
    writetxt(x, NULL, N, "dat/randb_mrg32k3a.txt");
 
    err = randb2(x, N, &rnd);
    if(err != RES_OK)
        goto exit_label;
 
    writetxt(x, NULL, N, "dat/randb2_mrg32k3a.txt");
 
    /**************************************************************************/
    /* plotting by GNUPLOT                                                    */
    /**************************************************************************/
    /* Create window plot */
    err = gnuplot_create(argc, argv, 820, 320, "img/randb_test.png", &hplot);
    if(err != RES_OK)
        goto exit_label;
 
    gnuplot_cmd(hplot, "set xlabel 'x'");
    gnuplot_cmd(hplot, "set ylabel 'y'");
    gnuplot_cmd(hplot, "unset key");
    gnuplot_cmd(hplot, "set yrange[-1.2:1.2]");
    gnuplot_cmd(hplot, "set title 'randb, randb2'");
    gnuplot_cmd(hplot, "plot 'dat/randb_mrg32k3a.txt' with lines, \\");
    gnuplot_cmd(hplot, "     'dat/randb2_mrg32k3a.txt' with lines");
 
exit_label:
    printf("Error code: %x\n", err);
    if(hplot)
        gnuplot_close(hplot);
 
    /* free dspl handle */
    dspl_free(hdspl);
    return 0;
}
 

Program genrates unipolar [0, 1] and bipolar[-1, 1] pseudorandom binary vectors.

As a result of the program run, you can see the graph:

Author

Sergey Bakhurin. www.dsplib.org

Definition at line 116 of file randb2.c.

random_init()

int random_init	(	random_t *	prnd,
		int	type,
		void *	seed
	)

Pseudorandom numbers generators initialization.

---

Parameters

[in,out]	prnd	Pointer to the pseudorandom generators parameters and state vectors.
[in]	type	Pseudorandom generator algorithm: RAND_TYPE_MRG32K3A - 32-bits MRG32K3A generator RAND_TYPE_MT19937 - 64-bits MT19937-64 generator
[in]	seed	Pointer to the generator start initialization. Type of this pointer is void* because different generators are using different initial values. For example, if we initialize the MRG32K3A generator, then the type parameter is specified asRAND_TYPE_MRG32K3A, and seed converts to double pointer: random_t rnd = {0}; double seed = 1234.0; random_init(&rnd, RAND_TYPE_MRG32K3A, (void*)&seed); For 64-bits Mersenne Twister pseudorandom number generator (type sets as RAND_TYPE_MT19937), seed converts to the unsigned long long pointer: random_t rnd = {0}; unsigned long long seed = 1234353456; random_init(&rnd, RAND_TYPE_MT19937, (void*)&seed); Pseudorandom numbers will be repeated each program restart if seed value is the same. The seed pointer can be NULL. Pseudorandom generators will be initialized by pseudorandom numbers in this case and program will generate different pseudorandom numbers each restart.

Author

Sergey Bakhurin. www.dsplib.org

Definition at line 120 of file random_init.c.