From 0f38b78093260fb0d29bf7368445af7eb15df53f Mon Sep 17 00:00:00 2001
From: Jens Ahrensfeld <jens@jayfield.org>
Date: Sun, 19 Oct 2014 20:28:36 +0000
Subject: [PATCH] - changed noise API - noise initialized with help of clock()

git-svn-id: http://moon:8086/svn/software/trunk/projects/RBM@33 b431acfa-c32f-4a4a-93f1-934dc6c82436
---
 Source/Layer.hpp   |  4 ++--
 Source/Weights.hpp |  6 +++---
 Source/noise.c     | 15 ++++++++-------
 Source/noise.h     |  4 ++--
 4 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/Source/Layer.hpp b/Source/Layer.hpp
index e4b23dd..c016eff 100644
--- a/Source/Layer.hpp
+++ b/Source/Layer.hpp
@@ -94,7 +94,7 @@ public:
 
 		for (i=0; i < m_numUnits; i++)
 		{
-			sample = Noise_Uniform(&m_noise, 0.5);
+			sample = Noise_Uniform(&m_noise);
 			m_states(i) = (double)(sample <= m_probs(i));
 		}
 	}
@@ -105,7 +105,7 @@ public:
 
 		for (i=0; i < m_numUnits; i++)
 		{
-			m_states(i) = Noise_Gaussian(&m_noise, 0, sigma) + lambda*accum(layer, weights, i);
+			m_states(i) = sigma*Noise_Gaussian(&m_noise) + lambda*accum(layer, weights, i);
 		}
 	}
 
diff --git a/Source/Weights.hpp b/Source/Weights.hpp
index b869c0d..a0d0bb0 100644
--- a/Source/Weights.hpp
+++ b/Source/Weights.hpp
@@ -71,19 +71,19 @@ public:
 
 		for (i=0; i < m_numVisible; i++)
 		{
-			m_bv(i) = kdev*Noise_Uniform(&m_noise, 0.5);
+			m_bv(i) = kdev*Noise_Uniform(&m_noise);
 		}
 
 		for (j=0; j < m_numHidden; j++)
 		{
-			m_bh(j) = kdev*Noise_Uniform(&m_noise, 0.5);
+			m_bh(j) = kdev*Noise_Uniform(&m_noise);
 		}
 
 		for (i=0; i < m_numVisible; i++)
 		{
 			for (j=0; j < m_numHidden; j++)
 			{
-				m_w(i,j) = kdev*Noise_Uniform(&m_noise, 0.5);
+				m_w(i,j) = kdev*Noise_Uniform(&m_noise);
 			}
 		}
 	}
diff --git a/Source/noise.c b/Source/noise.c
index c3be36c..00f8d4f 100644
--- a/Source/noise.c
+++ b/Source/noise.c
@@ -45,26 +45,28 @@ double ran0(long *idum)
 // --------------------------------------------------------------
 void Noise_Init(noise_gen_t *pObj, long seed)
 {
-	pObj->state = seed;
+
+	pObj->state = seed ^ clock();
 }
 
 void Noise_Free(noise_gen_t *pObj)
 {
 }
 
-double Noise_Uniform(noise_gen_t *pObj, double mu)
+// 0 .. 1
+double Noise_Uniform(noise_gen_t *pObj)
 {
-	return ran0(&pObj->state) + mu -0.5;
+	return ran0(&pObj->state);
 }
 
-double Noise_Gaussian(noise_gen_t *pObj, double mu, double sigma)
+double Noise_Gaussian(noise_gen_t *pObj)
 {
 	double U1, U2, V1, V2, S, Y;
 
 	do
 	{
-		U1 = Noise_Uniform(pObj, 0.5);                // U1=[0,1]
-		U2 = Noise_Uniform(pObj, 0.5);                // U2=[0,1]
+		U1 = Noise_Uniform(pObj);		         // U1=[0,1]
+		U2 = Noise_Uniform(pObj);                // U2=[0,1]
 		V1 = 2 * U1 - 1;          // V1=[-1,1]
 		V2 = 2 * U2 - 1;          // V2=[-1,1]
 		S = V1 * V1 + V2 * V2;
@@ -73,7 +75,6 @@ double Noise_Gaussian(noise_gen_t *pObj, double mu, double sigma)
 
 	// X = sqrt(-2 * log(S) / S) * V1;
 	Y = sqrt(-2 * log(S) / S) * V2;
-	Y = mu + sigma*Y;
 
 	return Y;
 }
diff --git a/Source/noise.h b/Source/noise.h
index 055c59b..cc56e29 100644
--- a/Source/noise.h
+++ b/Source/noise.h
@@ -30,8 +30,8 @@ extern "C" {
 // --------------------------------------------------------------
 void Noise_Init(noise_gen_t *pObj, long seed);
 void Noise_Free(noise_gen_t *pObj);
-double Noise_Uniform(noise_gen_t *pObj, double mu);
-double Noise_Gaussian(noise_gen_t *pObj, double mu, double sigma);
+double Noise_Uniform(noise_gen_t *pObj);
+double Noise_Gaussian(noise_gen_t *pObj);
 
 #if defined(__cplusplus)
 }