improve random number generation

ChangeLog

@@ -1,3 +1,9 @@
+2010-08-29 Holger Vogt
+ * cmath2.c, randnumb.c, main.c, ngspice.h, configure.in, tclspice.c: 
+   remove fcns random() and srandom(), only use rand() and srand() or
+   internal random number generator.
+ * mystring.c: replace Str() by SPICE_DSTRING  
+
 2010-08-29 Dietmar Warning
  * fteext.h, parse.c, cmath2.c, cmath2.h,: 
    new function sunif(), uniform random generator usable in control blocks

configure.in

@@ -662,9 +662,6 @@ if test "$ac_cv_have_decl_isnan" != yes; then
   AC_CHECK_FUNC(isnan)
 fi
 
-dnl Check for the random function:
-AC_CHECK_FUNCS(random,,AC_CHECK_LIB(iberty,random,AC_DEFINE([HAVE_RANDOM],1,[Have random in libiberty]) LIBS="$LIBS -liberty"))
-
 dnl If user enables garbage collection, look for garbage collector
 if test "$TCL_PACKAGE_PATH" = ""; then
   if test "$enable_gc" = "yes"; then

src/frontend/numparam/mystring.c

@@ -1042,7 +1042,9 @@ np_round (double x)
   double u;
   long z;
   int n;
-  Str (40, s);
+//  Str (40, s);
+  SPICE_DSTRING s ;
+  spice_dstring_init(&s) ;
   u = 2e9;
   if (x > u)
     x = u;

src/include/ngspice.h

@@ -175,6 +175,7 @@ extern struct timeb timebegin;
 #define inline _inline
 #endif
 
+/*
 #ifndef HAVE_RANDOM
 #define srandom(a) srand(a)
 #define random rand
@@ -182,6 +183,8 @@ extern struct timeb timebegin;
 #else
 #define RR_MAX LONG_MAX
 #endif
+*/
+#define RR_MAX RAND_MAX
 
 #ifdef HAVE_INDEX
 #   define strchr index

src/main.c

@@ -787,7 +787,7 @@ main(int argc, char **argv)
     }
     cp_program = ft_sim->simulator;
 
-    srandom(getpid());
+    srand(getpid()); //srandom(getpid());
     TausSeed();
 
     /* --- Process command line options --- */

src/maths/cmaths/cmath2.c

@@ -24,12 +24,12 @@ Author: 1985 Wayne A. Christopher, U. C. Berkeley CAD Group
 #include "cmath2.h"
 
 
-/* MINGW: random, srandom in libiberty.a, but not in libiberty.h */
+/* MINGW: random, srandom in libiberty.a, but not in libiberty.h 
 #if defined(__MINGW32__) && defined(HAVE_RANDOM)
 extern long int random (void);
 extern void srandom (unsigned int seed);
 #endif
-
+*/
 extern void checkseed(void); /* seed random or set by 'set rndseed=value'*/
 extern double drand(void);  /* from randnumb.c */
 extern double gauss(void);  /* from randnumb.c */
@@ -225,8 +225,8 @@ cx_rnd(void *data, short int type, int length, int *newlength, short int *newtyp
         int j, k;
         j = (int)floor(realpart(&cc[i]));
         k = (int)floor(imagpart(&cc[i]));
-        realpart(&c[i]) = j ? random() % j : 0;
-        imagpart(&c[i]) = k ? random() % k : 0;
+        realpart(&c[i]) = j ? rand() % j : 0; //random() % j : 0;
+        imagpart(&c[i]) = k ? rand() % k : 0; //random() % k : 0;
       }
       return ((void *) c);
     } else {
@@ -240,7 +240,7 @@ cx_rnd(void *data, short int type, int length, int *newlength, short int *newtyp
       int j;
 
       j = (int)floor(dd[i]);
-      d[i] = j ? random() % j : 0;
+      d[i] = j ? rand() % j : 0; //random() % j : 0;
     }
     return ((void *) d);
   }

src/maths/misc/randnumb.c

@@ -54,23 +54,18 @@ Copyright 2008 Holger Vogt
 
 /* Tausworthe state variables for double variates*/
 static unsigned CombState1 = 129, CombState2 = 130, CombState3 = 131;  
-static unsigned CombState4; /* LCG state variable */ 
+static unsigned CombState4 = 132; /* LCG state variable */ 
 
-/* Tausworthe state variables for double variates*/
+/* Tausworthe state variables for integer variates*/
 static unsigned CombState5 = 133, CombState6 = 135, CombState7 = 137;  
-static unsigned CombState8; /* LCG state variable */ 
-
-unsigned TauS(unsigned *state, int C1, int C2, int C3, unsigned m);
-unsigned LGCS(unsigned *state, unsigned A1, unsigned A2);
-void TausSeed(void);
+static unsigned CombState8 = 138; /* LCG state variable */ 
 
+static unsigned TauS(unsigned *state, int C1, int C2, int C3, unsigned m);
+static unsigned LGCS(unsigned *state, unsigned A1, unsigned A2);
 
-
-/* MINGW: random, srandom in libiberty.a, but not in libiberty.h */
-#if defined(__MINGW32__) && defined(HAVE_RANDOM)
-extern long int random (void);
-extern void srandom (unsigned int seed);
-#endif
+void TausSeed(void);
+double CombLCGTaus(void);
+unsigned int CombLCGTausInt(void);
 
 void checkseed(void);
 double drand(void);
@@ -89,7 +84,7 @@ void checkseed(void)
 /*   printf("Enter checkseed()\n"); */
    if (cp_getvar("rndseed", CP_NUM, &newseed)) {
       if ((newseed > 0) && (oldseed != newseed)) {
-         srandom(newseed);
+         srand(newseed); //srandom(newseed);
          TausSeed();
          oldseed = newseed;
          printf("Seed value for random number generator is set to %d\n", newseed);
@@ -103,50 +98,39 @@ void checkseed(void)
 double drand(void)
 {
    checkseed();
-   return ( 2.0*((double) (RR_MAX-abs(random())) / (double)RR_MAX-0.5));
+//   return ( 2.0*((double) (RR_MAX-abs(rand())) / (double)RR_MAX-0.5));
+   return 2.0 * CombLCGTaus() - 1.0;
 }
 
 
-
 void TausSeed(void)
 {    
-   CombState1 = CombState2 = CombState3 = 0;
-   /* The Tausworthe initial states should be greater than 128 */
-   while (CombState1 < 129)
-      CombState1 = rand();
-   while (CombState2 < 129)
-      CombState2 = rand();
-   while (CombState3 < 129)
-      CombState3 = rand();
-   while (CombState4 < 129)
-      CombState4 = rand();
+   /* The Tausworthe initial states should be greater than 128.
+      We restrict the values up to 32767 */
+   CombState1 = (unsigned int)((double)rand()/(double)RR_MAX * 32638.) + 129;
+   CombState2 = (unsigned int)((double)rand()/(double)RR_MAX * 32638.) + 129;
+   CombState3 = (unsigned int)((double)rand()/(double)RR_MAX * 32638.) + 129;
+   CombState4 = (unsigned int)((double)rand()/(double)RR_MAX * 32638.) + 129;
+   CombState5 = (unsigned int)((double)rand()/(double)RR_MAX * 32638.) + 129;
+   CombState6 = (unsigned int)((double)rand()/(double)RR_MAX * 32638.) + 129;
+   CombState7 = (unsigned int)((double)rand()/(double)RR_MAX * 32638.) + 129;
+   CombState8 = (unsigned int)((double)rand()/(double)RR_MAX * 32638.) + 129;
+
 #ifdef HVDEBUG
    printf("\nTausworthe Double generator init states: %d, %d, %d, %d\n", 
       CombState1, CombState2, CombState3, CombState4);
-#endif
-   CombState5 = CombState6 = CombState7 = 0;
-   /* The Tausworthe initial states should be greater than 128 */
-   while (CombState5 < 129)
-      CombState5 = rand();
-   while (CombState6 < 129)
-      CombState6 = rand();
-   while (CombState7 < 129)
-      CombState7 = rand();
-   while (CombState8 < 129)
-      CombState8 = rand();
-#ifdef HVDEBUG
    printf("Tausworthe Integer generator init states: %d, %d, %d, %d\n", 
       CombState5, CombState6, CombState7, CombState8);
 #endif
 }   
 
-unsigned TauS(unsigned *state, int C1, int C2, int C3, unsigned m)
+static unsigned TauS(unsigned *state, int C1, int C2, int C3, unsigned m)
 {
    unsigned b = (((*state << C1) ^ *state) >> C2);
    return *state = (((*state & m) << C3) ^ b);
 }
 
-unsigned LGCS(unsigned *state, unsigned A1, unsigned A2)
+static unsigned LGCS(unsigned *state, unsigned A1, unsigned A2)
 {
    return *state = (A1 * *state + A2);
 }
@@ -211,8 +195,6 @@ double gauss(void)
   if (gliset) {
     do {
       v1 = drand();  v2 = drand();
-//      v1 = 2.0 * CombLCGTaus() - 1.0;
-//      v2 = 2.0 * CombLCGTaus() - 1.0;
       r = v1*v1 + v2*v2;
     } while (r >= 1.0);
 /*    printf("v1 %f, v2 %f\n", v1, v2); */

src/tclspice.c

@@ -66,17 +66,11 @@ typedef pthread_t threadId_t;
     #undef BOOLEAN
     #include <windef.h>
     #include <winbase.h>  /* Sleep */
-	#ifndef srandom
-	    #define  srandom(a) srand(a) /* srandom */
-	#endif
 #elif defined(_MSC_VER)
    #include <stdarg.h>
    /* remove type incompatibility with winnt.h*/
    #undef BOOLEAN
    #include <windows.h> /* Sleep */
-	#ifndef srandom
-	    #define  srandom(a) srand(a) /* srandom */
-	#endif
    #include <process.h> /* _getpid */
    #define dup _dup
    #define dup2 _dup2