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GRASS 8 Programmer's Manual 8.6.0dev(2026)-f6f2c534ea
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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 <sys/time.h>#include <sys/types.h>#include <unistd.h>
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) | |
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.
Definition in file lrand48.c.
Generate a floating-point value in the range [0,1)
Definition at line 161 of file lrand48.c.
References r.
Referenced by f_rand(), and G_math_rand().
Generate an integer in the range [0, 2^31)
Definition at line 133 of file lrand48.c.
References r.
Referenced by Rast_make_random_colors().
Seed the pseudo-random number generator.
| [in] | seedval | 32-bit integer used to seed the PRNG |
Definition at line 52 of file lrand48.c.
Referenced by G_math_srand(), and G_srand48_auto().
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
Definition at line 70 of file lrand48.c.
References _, AMI_STREAM< T >::AMI_STREAM(), G_fatal_error(), G_srand48(), getpid, gettimeofday(), NULL, and t.
Referenced by G_math_srand_auto(), and Rast_make_random_colors().