Changeset 26598

Timestamp:

11/10/21 17:43:20 (3 years ago)

Author:

bulthuis

Message:

CHG: a few changes for random generators

Location:

issm/trunk-jpl/src/c/shared/Random

Files:

• randomgenerator.cpp (modified) (1 diff)
• randomgenerator.h (modified) (1 diff)

issm/trunk-jpl/src/c/shared/Random/randomgenerator.cpp

@@ -2 +2 @@
  * \brief random number generating functions
  */
+
+#include <iostream>
+#include "./randomgenerator.h"
+
+#undef M_PI
+#define M_PI 3.141592653589793238462643

issm/trunk-jpl/src/c/shared/Random/randomgenerator.h

@@ -2 +2 @@
  * \brief prototypes for randomgenerator.h
  */
+
+#ifndef _RANDOMGENERATOR_H_
+#define _RANDOMGENERATOR_H_
+
+/*Headers:*/
+/*{{{*/
+#include <cmath>
+/*}}}*/
+
+#undef M_PI
+#define M_PI 3.141592653589793238462643
+
+class rnd_uniform_distribution
+{
+
+  private:
+    int a;
+    int c;
+    unsigned int m;
+    unsigned _seed;
+    double lbound;
+    double ubound;
+
+  public:
+
+    /*constructors, destructors: */
+    rnd_uniform_distribution() : _seed( 0 ), a( 1103515245 ), c( 12345 ), m( 2147483648 ), lbound(0.0), ubound(1.0) {}
+    rnd_uniform_distribution(double a_1,double a_2) : _seed( 0 ), a( 1103515245 ), c( 12345 ), m( 2147483648 ), lbound(a_1), ubound(a_2) {}
+    ~rnd_uniform_distribution(){}
+
+    void seed( unsigned int s ) { _seed = s; }
+    unsigned int get_seed() { return _seed; }
+    double generator(){
+      _seed = ( a * _seed + c ) % m;
+      return (ubound-lbound)*(double) _seed/ m + lbound;
+    }
+
+};
+
+class rnd_normal_distribution
+{
+
+  private:
+    unsigned _seed;
+    double mean;
+    double sdev;
+
+  public:
+
+    /*constructors, destructors: */
+    rnd_normal_distribution() : _seed( 0 ), mean( 0), sdev(1.0) {}
+    rnd_normal_distribution(double m,double s) : _seed( 0 ), mean( m ), sdev(s) {}
+    ~rnd_normal_distribution(){}
+
+    void seed( unsigned int s ) { _seed = s; }
+    double generator()
+    {
+      rnd_uniform_distribution unifdistri;
+      unifdistri.seed(_seed);
+
+      double u1 = unifdistri.generator();
+      double u2 = unifdistri.generator();
+
+      double R = sqrt(-2*log(u1));
+      double theta = 2*M_PI*u2;
+
+      seed(unifdistri.get_seed());
+
+      return mean + sdev * (R*cos(theta));
+
+    }
+
+};
+
+#endif //ifndef _RANDOMGENERATOR_H_