lrand48.c File Reference

GIS Library - Pseudo-random number generation. More...

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <grass/gis.h>
#include <grass/glocale.h>
#include <time.h>
#include <sys/types.h>
#include <unistd.h>

Include dependency graph for lrand48.c:

Go to the source code of this file.

Macros
#define	LO(x)   ((x)&0xFFFFU)
#define	HI(x)   ((x) >> 16)

Typedefs
typedef unsigned short	uint16
typedef unsigned int	uint32
typedef signed int	int32

Functions
void	G_srand48 (long seedval)
	Seed the pseudo-random number generator.
long	G_srand48_auto (void)
	Seed the pseudo-random number generator from the time and PID.
long	G_lrand48 (void)
	Generate an integer in the range [0, 2^31)
long	G_mrand48 (void)
	Generate an integer in the range [-2^31, 2^31)
double	G_drand48 (void)
	Generate a floating-point value in the range [0,1)

Detailed Description

GIS Library - Pseudo-random number generation.

(C) 2014 by the GRASS Development Team

This program is free software under the GNU General Public License (>=v2). Read the file COPYING that comes with GRASS for details.

Author

Glynn Clements

Definition in file lrand48.c.

Macro Definition Documentation

HI

#define HI

(

x

)

((x) >> 16)

Definition at line 45 of file lrand48.c.

Referenced by G_srand48().

LO

#define LO

(

x

)

((x)&0xFFFFU)

Definition at line 44 of file lrand48.c.

Referenced by G_srand48().

Typedef Documentation

int32

typedef signed int int32

Definition at line 33 of file lrand48.c.

uint16

typedef unsigned short uint16

Definition at line 31 of file lrand48.c.

uint32

typedef unsigned int uint32

Definition at line 32 of file lrand48.c.

Function Documentation

G_drand48()

double G_drand48

(

void

)

Generate a floating-point value in the range [0,1)

Returns

the generated value

Definition at line 166 of file lrand48.c.

References r.

Referenced by f_rand(), and G_math_rand().

G_lrand48()

long G_lrand48

(

void

)

Generate an integer in the range [0, 2^31)

Returns

the generated value

Definition at line 136 of file lrand48.c.

References r.

G_mrand48()

long G_mrand48

(

void

)

Generate an integer in the range [-2^31, 2^31)

Returns

the generated value

Definition at line 151 of file lrand48.c.

References r.

Referenced by f_rand().

G_srand48()

void G_srand48

(

long

seedval

)

Seed the pseudo-random number generator.

Parameters

seedval

32-bit integer used to seed the PRNG

Definition at line 53 of file lrand48.c.

References HI, LO, and x.

Referenced by G_math_srand(), and G_srand48_auto().

G_srand48_auto()

long G_srand48_auto

(

void

)

Seed the pseudo-random number generator from the time and PID.

A weak hash of the current time and PID is generated and used to seed the PRNG

Returns

generated seed value passed to G_srand48()

Definition at line 72 of file lrand48.c.

References G_fatal_error(), G_srand48(), NULL, and t.

Referenced by G_math_srand_auto().