private static TrainingSessionResult Optimize(
SequentialNetwork network,
BatchesCollection miniBatches,
int epochs, float dropout,
[NotNull] WeightsUpdater updater,
[CanBeNull] IProgress <BatchProgress> batchProgress,
[CanBeNull] IProgress <TrainingProgressEventArgs> trainingProgress,
[CanBeNull] ValidationDataset validationDataset,
[CanBeNull] TestDataset testDataset,
CancellationToken token)
{
// Setup
DateTime startTime = DateTime.Now;
List <DatasetEvaluationResult>
validationReports = new List <DatasetEvaluationResult>(),
testReports = new List <DatasetEvaluationResult>();
TrainingSessionResult PrepareResult(TrainingStopReason reason, int loops)
{
return(new TrainingSessionResult(reason, loops, DateTime.Now.Subtract(startTime).RoundToSeconds(), validationReports, testReports));
}
// Convergence manager for the validation dataset
RelativeConvergence convergence = validationDataset == null
? null
: new RelativeConvergence(validationDataset.Tolerance, validationDataset.EpochsInterval);
// Optional batch monitor
BatchProgressMonitor batchMonitor = batchProgress == null ? null : new BatchProgressMonitor(miniBatches.Count, batchProgress);
// Create the training batches
for (int i = 0; i < epochs; i++)
{
// Shuffle the training set
miniBatches.CrossShuffle();
// Gradient descent over the current batches
for (int j = 0; j < miniBatches.BatchesCount; j++)
{
if (token.IsCancellationRequested)
{
return(PrepareResult(TrainingStopReason.TrainingCanceled, i));
}
network.Backpropagate(miniBatches.Batches[j], dropout, updater);
batchMonitor?.NotifyCompletedBatch(miniBatches.Batches[j].X.GetLength(0));
}
batchMonitor?.Reset();
// Check for overflows
if (!Parallel.For(0, network._Layers.Length, (j, state) =>
{
if (network._Layers[j] is WeightedLayerBase layer && !layer.ValidateWeights())
{
state.Break();
}
}).IsCompleted)
public static TrainingSessionResult TrainNetwork(
[NotNull] SequentialNetwork network, [NotNull] BatchesCollection batches,
int epochs, float dropout,
[NotNull] ITrainingAlgorithmInfo algorithm,
[CanBeNull] IProgress <BatchProgress> batchProgress,
[CanBeNull] IProgress <TrainingProgressEventArgs> trainingProgress,
[CanBeNull] ValidationDataset validationDataset,
[CanBeNull] TestDataset testDataset,
CancellationToken token)
{
SharedEventsService.TrainingStarting.Raise();
WeightsUpdater optimizer;
switch (algorithm)
{
/* =================
* Optimization
* =================
* The right optimizer is selected here, and the capatured closure for each of them also contains local temporary data, if needed.
* In this case, the temporary data is managed, so that it will automatically be disposed by the GC and there won't be the need to use
* another callback when the training stops to handle the cleanup of unmanaged resources. */
case MomentumInfo momentum:
optimizer = WeightsUpdaters.Momentum(momentum, network);
break;
case StochasticGradientDescentInfo sgd:
optimizer = WeightsUpdaters.StochasticGradientDescent(sgd);
break;
case AdaGradInfo adagrad:
optimizer = WeightsUpdaters.AdaGrad(adagrad, network);
break;
case AdaDeltaInfo adadelta:
optimizer = WeightsUpdaters.AdaDelta(adadelta, network);
break;
case AdamInfo adam:
optimizer = WeightsUpdaters.Adam(adam, network);
break;
case AdaMaxInfo adamax:
optimizer = WeightsUpdaters.AdaMax(adamax, network);
break;
case RMSPropInfo rms:
optimizer = WeightsUpdaters.RMSProp(rms, network);
break;
default:
throw new ArgumentException("The input training algorithm type is not supported");
}
return(Optimize(network, batches, epochs, dropout, optimizer, batchProgress, trainingProgress, validationDataset, testDataset, token));
}
private static TrainingSessionResult Optimize(
NeuralNetworkBase network,
BatchesCollection miniBatches,
int epochs, float dropout,
[NotNull] WeightsUpdater updater,
[CanBeNull] IProgress <BatchProgress> batchProgress,
[CanBeNull] IProgress <TrainingProgressEventArgs> trainingProgress,
[CanBeNull] ValidationDataset validationDataset,
[CanBeNull] TestDataset testDataset,
CancellationToken token)
{
// Setup
DateTime startTime = DateTime.Now;
List <DatasetEvaluationResult>
validationReports = new List <DatasetEvaluationResult>(),
testReports = new List <DatasetEvaluationResult>();
TrainingSessionResult PrepareResult(TrainingStopReason reason, int loops)
{
return(new TrainingSessionResult(reason, loops, DateTime.Now.Subtract(startTime).RoundToSeconds(), validationReports, testReports));
}
// Convergence manager for the validation dataset
RelativeConvergence convergence = validationDataset == null
? null
: new RelativeConvergence(validationDataset.Tolerance, validationDataset.EpochsInterval);
// Optional batch monitor
BatchProgressMonitor batchMonitor = batchProgress == null ? null : new BatchProgressMonitor(miniBatches.Count, batchProgress);
// Create the training batches
for (int i = 0; i < epochs; i++)
{
// Shuffle the training set
miniBatches.CrossShuffle();
// Gradient descent over the current batches
BackpropagationInProgress = true;
for (int j = 0; j < miniBatches.BatchesCount; j++)
{
if (token.IsCancellationRequested)
{
BackpropagationInProgress = false;
return(PrepareResult(TrainingStopReason.TrainingCanceled, i));
}
network.Backpropagate(miniBatches.Batches[j], dropout, updater);
batchMonitor?.NotifyCompletedBatch(miniBatches.Batches[j].X.GetLength(0));
}
BackpropagationInProgress = false;
batchMonitor?.Reset();
if (network.IsInNumericOverflow)
{
return(PrepareResult(TrainingStopReason.NumericOverflow, i));
}
// Check the training progress
if (trainingProgress != null)
{
(float cost, _, float accuracy) = network.Evaluate(miniBatches);
trainingProgress.Report(new TrainingProgressEventArgs(i + 1, cost, accuracy));
}
// Check the validation dataset
if (convergence != null)
{
(float cost, _, float accuracy) = network.Evaluate(validationDataset.Dataset);
validationReports.Add(new DatasetEvaluationResult(cost, accuracy));
convergence.Value = accuracy;
if (convergence.HasConverged)
{
return(PrepareResult(TrainingStopReason.EarlyStopping, i));
}
}
// Report progress if necessary
if (testDataset != null)
{
(float cost, _, float accuracy) = network.Evaluate(testDataset.Dataset);
testReports.Add(new DatasetEvaluationResult(cost, accuracy));
testDataset.ThreadSafeProgressCallback?.Report(new TrainingProgressEventArgs(i + 1, cost, accuracy));
}
}
return(PrepareResult(TrainingStopReason.EpochsCompleted, epochs));
}
