bool MatrixFloat::subtract(const MatrixFloat &a,const MatrixFloat &b){
const unsigned int M = a.getNumRows();
const unsigned int N = a.getNumCols();
if( M != b.getNumRows() ){
errorLog << "subtract(const MatrixFloat &a,const MatrixFloat &b) - Failed to add matrix! The rows do not match!";
errorLog << " a rows: " << M << " b rows: " << b.getNumRows() << std::endl;
return false;
}
if( N != b.getNumCols() ){
errorLog << "subtract(const MatrixFloat &a,const MatrixFloat &b) - Failed to add matrix! The columns do not match!";
errorLog << " a cols: " << N << " b cols: " << b.getNumCols() << std::endl;
return false;
}
resize( M, N );
UINT i,j;
//Using direct pointers really helps speed up the computation time
Float **pa = a.getDataPointer();
Float **pb = b.getDataPointer();
for(i=0; i<M; i++){
for(j=0; j<N; j++){
dataPtr[i*cols+j] = pa[i][j] - pb[i][j];
}
}
return true;
}
bool MatrixFloat::multiple(const MatrixFloat &a,const MatrixFloat &b,const bool aTranspose){
const unsigned int M = !aTranspose ? a.getNumRows() : a.getNumCols();
const unsigned int N = !aTranspose ? a.getNumCols() : a.getNumRows();
const unsigned int K = b.getNumRows();
const unsigned int L = b.getNumCols();
if( N != K ) {
errorLog << "multiple(const MatrixFloat &a,const MatrixFloat &b,const bool aTranspose) - The number of rows in a (" << K << ") does not match the number of columns in matrix b (" << N << ")" << std::endl;
return false;
}
if( !resize( M, L ) ){
errorLog << "multiple(const MatrixFloat &b,const MatrixFloat &c,const bool bTranspose) - Failed to resize matrix!" << std::endl;
return false;
}
unsigned int i, j, k = 0;
//Using direct pointers really helps speed up the computation time
Float **pa = a.getDataPointer();
Float **pb = b.getDataPointer();
if( aTranspose ){
for(j=0; j<L; j++){
for(i=0; i<M; i++){
dataPtr[i*cols+j] = 0;
for(k=0; k<K; k++){
dataPtr[i*cols+j] += pa[k][i] * pb[k][j];
}
}
}
}else{
for(j=0; j<L; j++){
for(i=0; i<M; i++){
dataPtr[i*cols+j] = 0;
for(k=0; k<K; k++){
dataPtr[i*cols+j] += pa[i][k] * pb[k][j];
}
}
}
}
return true;
}
MatrixFloat MatrixFloat::multiple(const MatrixFloat &b) const{
const unsigned int M = rows;
const unsigned int N = cols;
const unsigned int K = b.getNumRows();
const unsigned int L = b.getNumCols();
if( N != K ) {
errorLog << "multiple(MatrixFloat b) - The number of rows in b (" << K << ") does not match the number of columns in this matrix (" << N << ")" << std::endl;
return MatrixFloat();
}
MatrixFloat c(M,L);
Float **pb = b.getDataPointer();
Float **pc = c.getDataPointer();
unsigned int i,j,k = 0;
for(i=0; i<M; i++){
for(j=0; j<L; j++){
pc[i][j] = 0;
for(k=0; k<K; k++){
pc[i][j] += dataPtr[i*cols+k] * pb[k][j];
}
}
}
return c;
}
bool BernoulliRBM::train_(MatrixFloat &data){
const UINT numTrainingSamples = data.getNumRows();
numInputDimensions = data.getNumCols();
numOutputDimensions = numHiddenUnits;
numVisibleUnits = numInputDimensions;
trainingLog << "NumInputDimensions: " << numInputDimensions << std::endl;
trainingLog << "NumOutputDimensions: " << numOutputDimensions << std::endl;
if( randomizeWeightsForTraining ){
//Init the weights matrix
weightsMatrix.resize(numHiddenUnits, numVisibleUnits);
Float a = 1.0 / numVisibleUnits;
for(UINT i=0; i<numHiddenUnits; i++) {
for(UINT j=0; j<numVisibleUnits; j++) {
weightsMatrix[i][j] = rand.getRandomNumberUniform(-a, a);
}
}
//Init the bias units
visibleLayerBias.resize( numVisibleUnits );
hiddenLayerBias.resize( numHiddenUnits );
std::fill(visibleLayerBias.begin(),visibleLayerBias.end(),0);
std::fill(hiddenLayerBias.begin(),hiddenLayerBias.end(),0);
}else{
if( weightsMatrix.getNumRows() != numHiddenUnits ){
errorLog << "train_(MatrixFloat &data) - Weights matrix row size does not match the number of hidden units!" << std::endl;
return false;
}
if( weightsMatrix.getNumCols() != numVisibleUnits ){
errorLog << "train_(MatrixFloat &data) - Weights matrix row size does not match the number of visible units!" << std::endl;
return false;
}
if( visibleLayerBias.size() != numVisibleUnits ){
errorLog << "train_(MatrixFloat &data) - Visible layer bias size does not match the number of visible units!" << std::endl;
return false;
}
if( hiddenLayerBias.size() != numHiddenUnits ){
errorLog << "train_(MatrixFloat &data) - Hidden layer bias size does not match the number of hidden units!" << std::endl;
return false;
}
}
//Flag the model has been trained encase the user wants to save the model during a training iteration using an observer
trained = true;
//Make sure the data is scaled between [0 1]
ranges = data.getRanges();
if( useScaling ){
for(UINT i=0; i<numTrainingSamples; i++){
for(UINT j=0; j<numInputDimensions; j++){
data[i][j] = grt_scale(data[i][j], ranges[j].minValue, ranges[j].maxValue, 0.0, 1.0);
}
}
}
const UINT numBatches = static_cast<UINT>( ceil( Float(numTrainingSamples)/batchSize ) );
//Setup the batch indexs
Vector< BatchIndexs > batchIndexs( numBatches );
UINT startIndex = 0;
for(UINT i=0; i<numBatches; i++){
batchIndexs[i].startIndex = startIndex;
batchIndexs[i].endIndex = startIndex + batchSize;
//Make sure the last batch end index is not larger than the number of training examples
if( batchIndexs[i].endIndex >= numTrainingSamples ){
batchIndexs[i].endIndex = numTrainingSamples;
}
//Get the batch size
batchIndexs[i].batchSize = batchIndexs[i].endIndex - batchIndexs[i].startIndex;
//Set the start index for the next batch
startIndex = batchIndexs[i].endIndex;
}
Timer timer;
UINT i,j,n,epoch,noChangeCounter = 0;
Float startTime = 0;
Float alpha = learningRate;
Float error = 0;
Float err = 0;
Float delta = 0;
Float lastError = 0;
Vector< UINT > indexList(numTrainingSamples);
TrainingResult trainingResult;
MatrixFloat wT( numVisibleUnits, numHiddenUnits ); //Stores a transposed copy of the weights vector
MatrixFloat vW( numHiddenUnits, numVisibleUnits ); //Stores the weight velocity updates
MatrixFloat tmpW( numHiddenUnits, numVisibleUnits ); //Stores the weight values that will be used to update the main weights matrix at each batch update
MatrixFloat v1( batchSize, numVisibleUnits ); //Stores the real batch data during a batch update
MatrixFloat v2( batchSize, numVisibleUnits ); //Stores the sampled batch data during a batch update
MatrixFloat h1( batchSize, numHiddenUnits ); //Stores the hidden states given v1 and the current weightsMatrix
MatrixFloat h2( batchSize, numHiddenUnits ); //Stores the sampled hidden states given v2 and the current weightsMatrix
MatrixFloat c1( numHiddenUnits, numVisibleUnits ); //Stores h1' * v1
MatrixFloat c2( numHiddenUnits, numVisibleUnits ); //Stores h2' * v2
MatrixFloat vDiff( batchSize, numVisibleUnits ); //Stores the difference between v1-v2
MatrixFloat hDiff( batchSize, numVisibleUnits ); //Stores the difference between h1-h2
MatrixFloat cDiff( numHiddenUnits, numVisibleUnits ); //Stores the difference between c1-c2
VectorFloat vDiffSum( numVisibleUnits ); //Stores the column sum of vDiff
VectorFloat hDiffSum( numHiddenUnits ); //Stores the column sum of hDiff
VectorFloat visibleLayerBiasVelocity( numVisibleUnits ); //Stores the velocity update of the visibleLayerBias
VectorFloat hiddenLayerBiasVelocity( numHiddenUnits ); //Stores the velocity update of the hiddenLayerBias
//Set all the velocity weights to zero
vW.setAllValues( 0 );
std::fill(visibleLayerBiasVelocity.begin(),visibleLayerBiasVelocity.end(),0);
std::fill(hiddenLayerBiasVelocity.begin(),hiddenLayerBiasVelocity.end(),0);
//Randomize the order that the training samples will be used in
for(UINT i=0; i<numTrainingSamples; i++) indexList[i] = i;
if( randomiseTrainingOrder ){
std::random_shuffle(indexList.begin(), indexList.end());
}
//Start the main training loop
timer.start();
for(epoch=0; epoch<maxNumEpochs; epoch++) {
startTime = timer.getMilliSeconds();
error = 0;
//Randomize the batch order
std::random_shuffle(batchIndexs.begin(),batchIndexs.end());
//Run each of the batch updates
for(UINT k=0; k<numBatches; k+=batchStepSize){
//Resize the data matrices, the matrices will only be resized if the rows cols are different
v1.resize( batchIndexs[k].batchSize, numVisibleUnits );
h1.resize( batchIndexs[k].batchSize, numHiddenUnits );
v2.resize( batchIndexs[k].batchSize, numVisibleUnits );
h2.resize( batchIndexs[k].batchSize, numHiddenUnits );
//Setup the data pointers, using data pointers saves a few ms on large matrix updates
Float **w_p = weightsMatrix.getDataPointer();
Float **wT_p = wT.getDataPointer();
Float **vW_p = vW.getDataPointer();
Float **data_p = data.getDataPointer();
Float **v1_p = v1.getDataPointer();
Float **v2_p = v2.getDataPointer();
Float **h1_p = h1.getDataPointer();
Float **h2_p = h2.getDataPointer();
Float *vlb_p = &visibleLayerBias[0];
Float *hlb_p = &hiddenLayerBias[0];
//Get the batch data
UINT index = 0;
for(i=batchIndexs[k].startIndex; i<batchIndexs[k].endIndex; i++){
for(j=0; j<numVisibleUnits; j++){
v1_p[index][j] = data_p[ indexList[i] ][j];
}
index++;
}
//Copy a transposed version of the weights matrix, this is used to compute h1 and h2
for(i=0; i<numHiddenUnits; i++)
for(j=0; j<numVisibleUnits; j++)
wT_p[j][i] = w_p[i][j];
//Compute h1
h1.multiple(v1, wT);
for(n=0; n<batchIndexs[k].batchSize; n++){
for(i=0; i<numHiddenUnits; i++){
h1_p[n][i] = sigmoidRandom( h1_p[n][i] + hlb_p[i] );
}
}
//Compute v2
v2.multiple(h1, weightsMatrix);
for(n=0; n<batchIndexs[k].batchSize; n++){
for(i=0; i<numVisibleUnits; i++){
v2_p[n][i] = sigmoidRandom( v2_p[n][i] + vlb_p[i] );
}
}
//Compute h2
h2.multiple(v2,wT);
for(n=0; n<batchIndexs[k].batchSize; n++){
for(i=0; i<numHiddenUnits; i++){
h2_p[n][i] = grt_sigmoid( h2_p[n][i] + hlb_p[i] );
}
}
//Compute c1, c2 and the difference between v1-v2
c1.multiple(h1,v1,true);
c2.multiple(h2,v2,true);
vDiff.subtract(v1, v2);
//Compute the sum of vdiff
for(j=0; j<numVisibleUnits; j++){
vDiffSum[j] = 0;
for(i=0; i<batchIndexs[k].batchSize; i++){
vDiffSum[j] += vDiff[i][j];
}
}
//Compute the difference between h1 and h2
hDiff.subtract(h1, h2);
for(j=0; j<numHiddenUnits; j++){
hDiffSum[j] = 0;
for(i=0; i<batchIndexs[k].batchSize; i++){
hDiffSum[j] += hDiff[i][j];
}
}
//Compute the difference between c1 and c2
cDiff.subtract(c1,c2);
//Update the weight velocities
for(i=0; i<numHiddenUnits; i++){
for(j=0; j<numVisibleUnits; j++){
vW_p[i][j] = ((momentum * vW_p[i][j]) + (alpha * cDiff[i][j])) / batchIndexs[k].batchSize;
}
}
for(i=0; i<numVisibleUnits; i++){
visibleLayerBiasVelocity[i] = ((momentum * visibleLayerBiasVelocity[i]) + (alpha * vDiffSum[i])) / batchIndexs[k].batchSize;
}
for(i=0; i<numHiddenUnits; i++){
hiddenLayerBiasVelocity[i] = ((momentum * hiddenLayerBiasVelocity[i]) + (alpha * hDiffSum[i])) / batchIndexs[k].batchSize;
}
//Update the weights
weightsMatrix.add( vW );
//Update the bias for the visible layer
for(i=0; i<numVisibleUnits; i++){
visibleLayerBias[i] += visibleLayerBiasVelocity[i];
}
//Update the bias for the visible layer
for(i=0; i<numHiddenUnits; i++){
hiddenLayerBias[i] += hiddenLayerBiasVelocity[i];
}
//Compute the reconstruction error
err = 0;
for(i=0; i<batchIndexs[k].batchSize; i++){
for(j=0; j<numVisibleUnits; j++){
err += SQR( v1[i][j] - v2[i][j] );
}
}
error += err / batchIndexs[k].batchSize;
}
error /= numBatches;
delta = lastError - error;
lastError = error;
trainingLog << "Epoch: " << epoch+1 << "/" << maxNumEpochs;
trainingLog << " Epoch time: " << (timer.getMilliSeconds()-startTime)/1000.0 << " seconds";
trainingLog << " Learning rate: " << alpha;
trainingLog << " Momentum: " << momentum;
trainingLog << " Average reconstruction error: " << error;
trainingLog << " Delta: " << delta << std::endl;
//Update the learning rate
alpha *= learningRateUpdate;
trainingResult.setClassificationResult(epoch, error, this);
trainingResults.push_back(trainingResult);
trainingResultsObserverManager.notifyObservers( trainingResult );
//Check for convergance
if( fabs(delta) < minChange ){
if( ++noChangeCounter >= minNumEpochs ){
trainingLog << "Stopping training. MinChange limit reached!" << std::endl;
break;
}
}else noChangeCounter = 0;
}
trainingLog << "Training complete after " << epoch << " epochs. Total training time: " << timer.getMilliSeconds()/1000.0 << " seconds" << std::endl;
trained = true;
return true;
}