- improved cd_hinton()

- uniform() returns vector

source/Rbm.cpp

@@ -17,7 +17,7 @@
 
 using namespace Matutils;
 
-#define USE_CD_HINTON 0
+#define USE_CD_HINTON 1
 
 Rbm::Rbm(size_t numVisible, size_t numHidden)
 : m_params()
@@ -97,9 +97,9 @@ void Rbm::weightsAssign(const arma::mat& w, const arma::mat& bh, const arma::mat
 
 void Rbm::weightsInit(double stddev, double mu)
 {
-	uniform(m_whv, stddev, mu);
-	uniform(m_bh, 0, mu);
-	uniform(m_bv, 0, mu);
+	m_whv = uniform(m_whv, stddev, mu);
+	m_bh = uniform(m_bh, 0, 0);
+	m_bv = uniform(m_bv, 0, 0);
 }
 
 void Rbm::fromJson(Json::Value rbm)
@@ -190,7 +190,14 @@ void Rbm::cd_hinton(arma::mat const &v_data, arma::mat &dw, arma::mat &dbh, arma
 
 	if (m_params.doGaussianHidden)
 	{
-		poshidstates = poshidprobs + arma::randn(arma::size(poshidprobs));
+		if (m_params.gibbsDoSampleHidden)
+		{
+			poshidstates = poshidprobs + arma::randn(arma::size(poshidprobs));
+		}
+		else
+		{
+			poshidstates = poshidprobs;
+		}
 	}
 	else
 	{
@@ -212,7 +219,15 @@ void Rbm::cd_hinton(arma::mat const &v_data, arma::mat &dw, arma::mat &dbh, arma
 	for (int i=0; i < m_params.numGibbs; i++)
 	{
 		// Start negative phase	
-		arma::mat negdata = toVisibleProbs(poshidstates);
+		arma::mat negdata;
+		if (m_params.gibbsDoSampleHidden)
+		{
+			negdata = toVisibleProbs(sample(poshidstates));
+		}
+		else
+		{
+			negdata = toVisibleProbs(poshidstates);
+		}
 		arma::mat neghidprobs;
 		if (m_params.gibbsDoSampleVisible)
 		{
@@ -226,14 +241,7 @@ void Rbm::cd_hinton(arma::mat const &v_data, arma::mat &dw, arma::mat &dbh, arma
 		neghidact = arma::sum(neghidprobs);
 		negvisact = arma::sum(negdata);
 
-		if (m_params.gibbsDoSampleHidden)
-		{
-			poshidprobs = sample(neghidprobs);
-		}
-		else
-		{
-			poshidprobs = neghidprobs;
-		}
+		poshidprobs = neghidprobs;
 	}
 	// Update weight deltas
 	dw = posprods - negprods;