| /* lran2.h | |
| * by Wolfram Gloger 1996. | |
| * | |
| * A small, portable pseudo-random number generator. | |
| */ | |
| #ifndef _LRAN2_H | |
| #define _LRAN2_H | |
| #define LRAN2_MAX 714025l /* constants for portable */ | |
| #define IA 1366l /* random number generator */ | |
| #define IC 150889l /* (see e.g. `Numerical Recipes') */ | |
| struct lran2_st { | |
| long x, y, v[97]; | |
| }; | |
| static void | |
| lran2_init(struct lran2_st* d, long seed) | |
| { | |
| long x; | |
| int j; | |
| x = (IC - seed) % LRAN2_MAX; | |
| if(x < 0) x = -x; | |
| for(j=0; j<97; j++) { | |
| x = (IA*x + IC) % LRAN2_MAX; | |
| d->v[j] = x; | |
| } | |
| d->x = (IA*x + IC) % LRAN2_MAX; | |
| d->y = d->x; | |
| } | |
| #ifdef __GNUC__ | |
| __inline__ | |
| #endif | |
| static long | |
| lran2(struct lran2_st* d) | |
| { | |
| int j = (d->y % 97); | |
| d->y = d->v[j]; | |
| d->x = (IA*d->x + IC) % LRAN2_MAX; | |
| d->v[j] = d->x; | |
| return d->y; | |
| } | |
| #undef IA | |
| #undef IC | |
| #endif |