1 files changed, 180 insertions, 0 deletions
diff --git a/gnuradio-core/src/lib/general/gr_random.cc b/gnuradio-core/src/lib/general/gr_random.cc
new file mode 100644
index 0000000000..a56f2875b5
--- /dev/null
+++ b/gnuradio-core/src/lib/general/gr_random.cc
@@ -0,0 +1,180 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2002 Free Software Foundation, Inc.
+ * 
+ * This file is part of GNU Radio
+ * 
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ * 
+ * GNU Radio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/*
+ *  Copyright 1997 Massachusetts Institute of Technology
+ * 
+ *  Permission to use, copy, modify, distribute, and sell this software and its
+ *  documentation for any purpose is hereby granted without fee, provided that
+ *  the above copyright notice appear in all copies and that both that
+ *  copyright notice and this permission notice appear in supporting
+ *  documentation, and that the name of M.I.T. not be used in advertising or
+ *  publicity pertaining to distribution of the software without specific,
+ *  written prior permission.  M.I.T. makes no representations about the
+ *  suitability of this software for any purpose.  It is provided "as is"
+ *  without express or implied warranty.
+ * 
+ */
+
+#include <math.h>
+#include <gr_random.h>
+
+#define IA 16807
+#define IM 2147483647
+#define AM (1.0/IM)
+#define IQ 127773
+#define IR 2836
+#define NDIV (1+(IM-1)/NTAB)
+#define EPS 1.2e-7
+#define RNMX (1.0-EPS)
+
+
+gr_random::gr_random (long seed)
+{
+  reseed (seed);
+}
+
+void
+gr_random::reseed (long seed)
+{
+  d_seed = seed;
+  d_iy = 0;
+  for (int i = 0; i < NTAB; i++)
+    d_iv[i] = 0;
+  d_iset = 0;
+  d_gset = 0;
+}
+
+/*
+ * This looks like it returns a uniform random deviate between 0.0 and 1.0
+ * It looks similar to code from "Numerical Recipes in C".
+ */
+float gr_random::ran1()
+{
+  int j;
+  long k;
+  float temp;
+  
+  if (d_seed <= 0 || !d_iy)  {
+    if (-d_seed < 1) 
+      d_seed=1;
+    else 
+      d_seed = -d_seed;
+    for (j=NTAB+7;j>=0;j--) {
+      k=d_seed/IQ;
+      d_seed=IA*(d_seed-k*IQ)-IR*k;
+      if (d_seed < 0) 
+	d_seed += IM;
+      if (j < NTAB) 
+	d_iv[j] = d_seed;
+    }
+    d_iy=d_iv[0];
+  }
+  k=(d_seed)/IQ;
+  d_seed=IA*(d_seed-k*IQ)-IR*k;
+  if (d_seed < 0)
+    d_seed += IM;
+  j=d_iy/NDIV;
+  d_iy=d_iv[j];
+  d_iv[j] = d_seed;
+  temp=AM * d_iy;
+  if (temp > RNMX)
+    temp = RNMX;
+  return temp;
+}
+
+/*
+ * Returns a normally distributed deviate with zero mean and variance 1.
+ * Also looks like it's from "Numerical Recipes in C".
+ */
+float gr_random::gasdev()
+{
+  float fac,rsq,v1,v2;
+  d_iset = 1 - d_iset;
+  if  (d_iset) {
+    do {
+      v1=2.0*ran1()-1.0;
+      v2=2.0*ran1()-1.0;
+      rsq=v1*v1+v2*v2;
+    } while (rsq >= 1.0 || rsq == 0.0);
+    fac= sqrt(-2.0*log(rsq)/rsq);
+    d_gset=v1*fac;
+    return v2*fac;
+  }
+  return d_gset;
+}
+
+/*
+ * Copied from The KC7WW / OH2BNS Channel Simulator
+ * FIXME Need to check how good this is at some point
+ */
+
+float gr_random::laplacian()
+{
+  float z = ran1();
+  if (z < 0.5)
+    return log(2.0 * z) / M_SQRT2;
+  else
+    return -log(2.0 * (1.0 - z)) / M_SQRT2;
+}
+
+/*
+ * Copied from The KC7WW / OH2BNS Channel Simulator
+ * FIXME Need to check how good this is at some point
+ */
+
+  // 5 => scratchy, 8 => Geiger
+
+float gr_random::impulse(float factor = 5)
+{
+  float z = -M_SQRT2 * log(ran1());
+  if (fabsf(z) <= factor)		
+    return 0.0;
+  else 
+    return z;
+}
+
+/*
+ * Complex rayleigh is really gaussian I and gaussian Q
+ * It can also be generated by real rayleigh magnitude and
+ * uniform random angle 
+ * Adapted from The KC7WW / OH2BNS Channel Simulator
+ * FIXME Need to check how good this is at some point
+ */
+
+gr_complex gr_random::rayleigh_complex()
+{
+  return gr_complex(gasdev(),gasdev());
+}
+
+/*   Other option
+     mag = rayleigh();
+     ang = 2.0 * M_PI * RNG();
+     *Rx = rxx * cos(z);
+     *Iy = rxx * sin(z);
+*/
+
+
+float gr_random::rayleigh()
+{
+  return sqrt(-2.0 * log(ran1()));
+}