diff options
author | Eric Andersen <andersen@codepoet.org> | 2001-11-22 14:04:29 +0000 |
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committer | Eric Andersen <andersen@codepoet.org> | 2001-11-22 14:04:29 +0000 |
commit | 7ce331c01ce6eb7b3f5c715a38a24359da9c6ee2 (patch) | |
tree | 3a7e8476e868ae15f4da1b7ce26b2db6f434468c /libm/ldouble/ldrand.c | |
parent | c117dd5fb183afb1a4790a6f6110d88704be6bf8 (diff) |
Totally rework the math library, this time based on the MacOs X
math library (which is itself based on the math lib from FreeBSD).
-Erik
Diffstat (limited to 'libm/ldouble/ldrand.c')
-rw-r--r-- | libm/ldouble/ldrand.c | 175 |
1 files changed, 0 insertions, 175 deletions
diff --git a/libm/ldouble/ldrand.c b/libm/ldouble/ldrand.c deleted file mode 100644 index 892b465df..000000000 --- a/libm/ldouble/ldrand.c +++ /dev/null @@ -1,175 +0,0 @@ -/* ldrand.c - * - * Pseudorandom number generator - * - * - * - * SYNOPSIS: - * - * double y; - * int ldrand(); - * - * ldrand( &y ); - * - * - * - * DESCRIPTION: - * - * Yields a random number 1.0 <= y < 2.0. - * - * The three-generator congruential algorithm by Brian - * Wichmann and David Hill (BYTE magazine, March, 1987, - * pp 127-8) is used. - * - * Versions invoked by the different arithmetic compile - * time options IBMPC, and MIEEE, produce the same sequences. - * - */ - - - -#include <math.h> -#ifdef ANSIPROT -int ranwh ( void ); -#else -int ranwh(); -#endif -#ifdef UNK -#undef UNK -#if BIGENDIAN -#define MIEEE -#else -#define IBMPC -#endif -#endif - -/* Three-generator random number algorithm - * of Brian Wichmann and David Hill - * BYTE magazine, March, 1987 pp 127-8 - * - * The period, given by them, is (p-1)(q-1)(r-1)/4 = 6.95e12. - */ - -static int sx = 1; -static int sy = 10000; -static int sz = 3000; - -static union { - long double d; - unsigned short s[8]; -} unkans; - -/* This function implements the three - * congruential generators. - */ - -int ranwh() -{ -int r, s; - -/* sx = sx * 171 mod 30269 */ -r = sx/177; -s = sx - 177 * r; -sx = 171 * s - 2 * r; -if( sx < 0 ) - sx += 30269; - - -/* sy = sy * 172 mod 30307 */ -r = sy/176; -s = sy - 176 * r; -sy = 172 * s - 35 * r; -if( sy < 0 ) - sy += 30307; - -/* sz = 170 * sz mod 30323 */ -r = sz/178; -s = sz - 178 * r; -sz = 170 * s - 63 * r; -if( sz < 0 ) - sz += 30323; -/* The results are in static sx, sy, sz. */ -return 0; -} - -/* ldrand.c - * - * Random double precision floating point number between 1 and 2. - * - * C callable: - * drand( &x ); - */ - -int ldrand( a ) -long double *a; -{ -unsigned short r; - -/* This algorithm of Wichmann and Hill computes a floating point - * result: - */ -ranwh(); -unkans.d = sx/30269.0L + sy/30307.0L + sz/30323.0L; -r = unkans.d; -unkans.d -= r; -unkans.d += 1.0L; - -if( sizeof(long double) == 16 ) - { -#ifdef MIEEE - ranwh(); - r = sx * sy + sz; - unkans.s[7] = r; - ranwh(); - r = sx * sy + sz; - unkans.s[6] = r; - ranwh(); - r = sx * sy + sz; - unkans.s[5] = r; - ranwh(); - r = sx * sy + sz; - unkans.s[4] = r; - ranwh(); - r = sx * sy + sz; - unkans.s[3] = r; -#endif -#ifdef IBMPC - ranwh(); - r = sx * sy + sz; - unkans.s[0] = r; - ranwh(); - r = sx * sy + sz; - unkans.s[1] = r; - ranwh(); - r = sx * sy + sz; - unkans.s[2] = r; - ranwh(); - r = sx * sy + sz; - unkans.s[3] = r; - ranwh(); - r = sx * sy + sz; - unkans.s[4] = r; -#endif - } -else - { -#ifdef MIEEE - ranwh(); - r = sx * sy + sz; - unkans.s[5] = r; - ranwh(); - r = sx * sy + sz; - unkans.s[4] = r; -#endif -#ifdef IBMPC - ranwh(); - r = sx * sy + sz; - unkans.s[0] = r; - ranwh(); - r = sx * sy + sz; - unkans.s[1] = r; -#endif - } -*a = unkans.d; -return 0; -} |