1 files changed, 68 insertions, 0 deletions
diff --git a/gnu/lib/libg++/include/Erlang.h b/gnu/lib/libg++/include/Erlang.h
new file mode 100644
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+++ b/gnu/lib/libg++/include/Erlang.h
@@ -0,0 +1,68 @@
+// This may look like C code, but it is really -*- C++ -*-
+/* 
+Copyright (C) 1988 Free Software Foundation
+    written by Dirk Grunwald (grunwald@cs.uiuc.edu)
+
+This file is part of the GNU C++ Library.  This library is free
+software; you can redistribute it and/or modify it under the terms of
+the GNU Library General Public License as published by the Free
+Software Foundation; either version 2 of the License, or (at your
+option) any later version.  This library 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 Library General Public License for more details.
+You should have received a copy of the GNU Library General Public
+License along with this library; if not, write to the Free Software
+Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+#ifndef _Erlang_h
+#ifdef __GNUG__
+#pragma interface
+#endif
+#define _Erlang_h 1 
+
+#include <Random.h>
+
+class Erlang: public Random {
+protected:
+    double pMean;
+    double pVariance;
+    int k;
+    double a;
+    void setState();
+public:
+    Erlang(double mean, double variance, RNG *gen);
+
+    double mean();
+    double mean(double x);
+    double variance();
+    double variance(double x);
+
+    virtual double operator()();
+
+};
+
+
+inline void Erlang::setState() {
+  k = int( (pMean * pMean ) / pVariance + 0.5 );
+  k = (k > 0) ? k : 1;
+  a = k / pMean;
+}
+
+inline Erlang::Erlang(double mean, double variance, RNG *gen) : Random(gen)
+{
+  pMean = mean; pVariance = variance;
+  setState();
+}
+
+inline double Erlang::mean() { return pMean; }
+inline double Erlang::mean(double x) {
+  double tmp = pMean; pMean = x; setState(); return tmp;
+};
+
+inline double Erlang::variance() { return pVariance; }
+inline double Erlang::variance(double x) {
+  double tmp = pVariance; pVariance = x; setState(); return tmp;
+}
+
+#endif