// @(#)root/mlp:$Name: $:$Id: TSynapse.cxx,v 1.6 2006/05/26 15:13:02 rdm Exp $ // Author: Christophe.Delaere@cern.ch 21/08/2002 /************************************************************************* * Copyright (C) 1995-2003, Rene Brun and Fons Rademakers. * * All rights reserved. * * * * For the licensing terms see $ROOTSYS/LICENSE. * * For the list of contributors see $ROOTSYS/README/CREDITS. * *************************************************************************/ /////////////////////////////////////////////////////////////////////////// // // TSynapse // // This is a simple weighted bidirectionnal connection between // two neurons. // A network is built connecting two neurons by a synapse. // In addition to the value, the synapse can return the DeDw // /////////////////////////////////////////////////////////////////////////// #include "TSynapse.h" #include "TNeuron.h" #include "Riostream.h" ClassImp(TSynapse) //______________________________________________________________________________ TSynapse::TSynapse() { // Default constructor fpre = 0; fpost = 0; fweight = 1; fDEDw = 0; } //______________________________________________________________________________ TSynapse::TSynapse(TNeuron * pre, TNeuron * post, Double_t w) { // Constructor that connects two neurons fpre = pre; fpost = post; fweight = w; fDEDw = 0; pre->AddPost(this); post->AddPre(this); } //______________________________________________________________________________ void TSynapse::SetPre(TNeuron * pre) { // Sets the pre-neuron if (pre) { Error("SetPre","this synapse is already assigned to a pre-neuron."); return; } fpre = pre; pre->AddPost(this); } //______________________________________________________________________________ void TSynapse::SetPost(TNeuron * post) { // Sets the post-neuron if (post) { Error("SetPost","this synapse is already assigned to a post-neuron."); return; } fpost = post; post->AddPre(this); } //______________________________________________________________________________ Double_t TSynapse::GetValue() const { // Returns the value: weithted input if (fpre) return (fweight * fpre->GetValue()); return 0; } //______________________________________________________________________________ Double_t TSynapse::GetDeDw() const { // Computes the derivative of the error wrt the synapse weight. if (!(fpre && fpost)) return 0; return (fpre->GetValue() * fpost->GetDeDw()); } //______________________________________________________________________________ void TSynapse::SetWeight(Double_t w) { // Sets the weight of the synapse. // This weight is the multiplying factor applied on the // output of a neuron in the linear combination given as input // of another neuron. fweight = w; } //______________________________________________________________________________ void TSynapse::SetDEDw(Double_t in) { // Sets the derivative of the total error wrt the synapse weight fDEDw = in; }