From 7c3c5dd0f8d7089bd50282e9dcd56e36798e18cf Mon Sep 17 00:00:00 2001
From: Georg Holzmann <grholzi@users.sourceforge.net>
Date: Tue, 12 Jul 2005 14:40:21 +0000
Subject: initial commit of pix_recNN

svn path=/trunk/externals/grh/; revision=3320
---
 pix_recNN/Neuron.cpp | 169 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 169 insertions(+)
 create mode 100755 pix_recNN/Neuron.cpp

(limited to 'pix_recNN/Neuron.cpp')

diff --git a/pix_recNN/Neuron.cpp b/pix_recNN/Neuron.cpp
new file mode 100755
index 0000000..c020c1c
--- /dev/null
+++ b/pix_recNN/Neuron.cpp
@@ -0,0 +1,169 @@
+/////////////////////////////////////////////////////////////////////////////
+//
+// class Neuron
+//
+//   source file
+//
+//   Copyright (c) 2005 Georg Holzmann <grh@gmx.at>
+//
+//   This program 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
+//   of the License, or (at your option) any later version. 
+//
+/////////////////////////////////////////////////////////////////////////////
+
+#include "Neuron.h"
+
+namespace TheBrain
+{
+
+//--------------------------------------------------
+/* Constructor
+ */
+Neuron::Neuron(int inputs, int dummy)
+  : learn_rate_(0), range_(1), IW_(NULL), b1_(0)
+{
+  inputs_ = (inputs<1) ? 1 : inputs;
+}
+
+//--------------------------------------------------
+/* Destructor
+ */
+Neuron::~Neuron()
+{
+  if(IW_)
+    delete[] IW_;
+}
+
+//--------------------------------------------------
+/* creates a new IW-matrix (size: inputs_) and 
+ * b1-vector
+ * ATTENTION: if they exist they'll be deleted
+ */
+void Neuron::create()
+  throw(NNExcept)
+{
+  // delete if they exist
+  if(IW_)
+    delete[] IW_;
+
+  IW_ = new float[inputs_];
+  if(!IW_)
+    throw NNExcept("No memory for Neurons!");
+}
+
+//--------------------------------------------------
+/* inits the weight matrix and the bias vector of
+ * the network with random values between [min|max]
+ */
+void Neuron::initRand(const int &min, const int &max)
+  throw(NNExcept)
+{
+  if(!IW_)
+    throw NNExcept("You must first create the Net!");
+
+  // make randomvalue between 0 and 1
+  // then map it to the bounds
+  b1_ = ((float)rand()/(float)RAND_MAX)*(max-min) + min;
+
+  for(int i=0; i<inputs_; i++)
+    {
+      IW_[i] = ((float)rand()/(float)RAND_MAX)*(max-min) + min;
+    }
+
+  //post("b1: %f, IW: %f %f %f", b1_, IW_[0], IW_[1], IW_[2]);
+}
+
+//--------------------------------------------------
+/* inits the net with a given weight matrix and bias
+ * (makes a deep copy)
+ * ATTENTION: the dimension of IW-pointer must be the same
+ *            as the inputs !!!
+ */
+void Neuron::init(const float *IW, float b1)
+  throw(NNExcept)
+{
+  if(!IW_)
+    throw NNExcept("You must first create the Net!");
+
+  b1_ = b1;
+
+  for(int i=0; i<inputs_; i++)
+      IW_[i] = IW[i];
+}
+
+//--------------------------------------------------
+/* calculates the output with the current IW, b1 values
+ * ATTENTION: the array input_data must be in the same
+ *            size as inputs_
+ */
+float Neuron::calculate(float *input_data)
+{
+  float output = 0;
+
+  // multiply the inputs with the weight matrix IW
+  // and add the bias vector b1
+  for(int i=0; i<inputs_; i++)
+    {
+      output += input_data[i] * IW_[i];
+    }
+
+  // map input values to the range
+  output /= range_; 
+  
+  //post("b1: %f, IW: %f %f %f", b1_, IW_[0], IW_[1], IW_[2]);
+  //post("range: %f, in: %f %f %f, out: %f",range_,input_data[0],
+  //     input_data[1], input_data[2], output+b1_);
+
+  return (output+b1_);
+}
+
+//--------------------------------------------------
+/* this method trains the network:
+ * input_data is, as above, the input data, output_data is the 
+ * output of the current net with input_data (output_data is not
+ * calculated in that method !), target_output is the desired
+ * output data
+ * (this is the LMS-algorithm to train linear neural networks)
+ * ATTENTION: the array input_data must be in the same
+ *            size as inputs_
+ * returns the calculated value
+ */
+// float Neuron::trainLMS(const float *input_data, 
+// 		       const float &target_output)
+// {
+//   float output = 0;
+
+//   // multiply the inputs with the weight matrix IW
+//   // and add the bias vector b1
+//   for(int i=0; i<inputs_; i++)
+//     {
+//       output += input_data[i] * IW_[i];
+//     }
+
+//   // map input values to the range
+//   output /= range_; 
+
+//   output += b1_;
+
+//   //------------
+
+//   // this is the LMS-algorithm to train linear
+//   // neural networks
+  
+//   // calculate the error signal:
+//   float error = (target_output - output);
+
+//   // now change the weights the bias
+//   for(int i=0; i<inputs_; i++)
+//     IW_[i] += 2 * learn_rate_ * error * (input_data[i]/range_);
+
+//   b1_ += 2 * learn_rate_ * error; 
+
+//   //------------
+
+//   return (output);
+// }
+
+} // end of namespace
-- 
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