From 45b298139d494ee81ce9ea23424faaba5f177230 Mon Sep 17 00:00:00 2001
From: bothameister <bothameister@ec762483-ff6d-05da-a07a-a48fb63a330f>
Date: Tue, 6 Jul 2010 15:23:32 +0000
Subject: removed dependency on gammadist.c to be absolutely sure our code
 doesn't use the old non-threadsafe RNG

git-svn-id: https://ws10smt.googlecode.com/svn/trunk@149 ec762483-ff6d-05da-a07a-a48fb63a330f
---
 gi/pyp-topics/src/Makefile.am |  4 ++--
 gi/pyp-topics/src/pyp.hh      | 30 +++++++++++++++++++++++++++++-
 2 files changed, 31 insertions(+), 3 deletions(-)

(limited to 'gi/pyp-topics')

diff --git a/gi/pyp-topics/src/Makefile.am b/gi/pyp-topics/src/Makefile.am
index e4c4c1b9..681a9a0c 100644
--- a/gi/pyp-topics/src/Makefile.am
+++ b/gi/pyp-topics/src/Makefile.am
@@ -3,10 +3,10 @@ bin_PROGRAMS = pyp-topics-train pyp-contexts-train
 contexts_lexer.cc: contexts_lexer.l
 	$(LEX) -s -CF -8 -o$@ $<
 
-pyp_topics_train_SOURCES = corpus.cc gammadist.c gzstream.cc mt19937ar.c pyp-topics.cc train.cc contexts_lexer.cc contexts_corpus.cc
+pyp_topics_train_SOURCES = corpus.cc gzstream.cc mt19937ar.c pyp-topics.cc train.cc contexts_lexer.cc contexts_corpus.cc
 pyp_topics_train_LDADD = $(top_srcdir)/decoder/libcdec.a -lz
 
-pyp_contexts_train_SOURCES = corpus.cc gammadist.c gzstream.cc mt19937ar.c pyp-topics.cc contexts_lexer.cc contexts_corpus.cc train-contexts.cc
+pyp_contexts_train_SOURCES = corpus.cc gzstream.cc mt19937ar.c pyp-topics.cc contexts_lexer.cc contexts_corpus.cc train-contexts.cc
 pyp_contexts_train_LDADD = $(top_srcdir)/decoder/libcdec.a -lz
 
 AM_CPPFLAGS = -W -Wall -Wno-sign-compare -funroll-loops
diff --git a/gi/pyp-topics/src/pyp.hh b/gi/pyp-topics/src/pyp.hh
index 64fb5b58..7a520d6a 100644
--- a/gi/pyp-topics/src/pyp.hh
+++ b/gi/pyp-topics/src/pyp.hh
@@ -10,7 +10,6 @@
 #include <boost/random/mersenne_twister.hpp>
 
 #include "log_add.h"
-#include "gammadist.h"
 #include "slice-sampler.h"
 
 //
@@ -132,6 +131,17 @@ private:
       return log_prob + log_prior;
     }
   };
+   
+   /* lbetadist() returns the log probability density of x under a Beta(alpha,beta)
+   * distribution. - copied from Mark Johnson's gammadist.c
+   */
+    static long double lbetadist(long double x, long double alpha, long double beta);
+
+   /* lgammadist() returns the log probability density of x under a Gamma(alpha,beta)
+   * distribution - copied from Mark Johnson's gammadist.c
+   */
+  static long double lgammadist(long double x, long double alpha, long double beta);
+
 };
 
 template <typename Dish, typename Hash>
@@ -462,6 +472,24 @@ PYP<Dish,Hash>::log_prior_b(double b, double gamma_c, double gamma_s) {
   return lgammadist(b, gamma_c, gamma_s); 
 }
 
+template <typename Dish, typename Hash>
+long double PYP<Dish,Hash>::lbetadist(long double x, long double alpha, long double beta) {
+  assert(x > 0);
+  assert(x < 1);
+  assert(alpha > 0);
+  assert(beta > 0);
+  return (alpha-1)*log(x)+(beta-1)*log(1-x)+lgamma(alpha+beta)-lgamma(alpha)-lgamma(beta);
+//boost::math::lgamma
+}
+
+template <typename Dish, typename Hash>
+long double PYP<Dish,Hash>::lgammadist(long double x, long double alpha, long double beta) {
+  assert(alpha > 0);
+  assert(beta > 0);
+  return (alpha-1)*log(x) - alpha*log(beta) - x/beta - lgamma(alpha);
+}
+
+
 template <typename Dish, typename Hash>
 void 
 PYP<Dish,Hash>::resample_prior() {
-- 
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