/// <summary>
/// Create a MNIST trainer (writing recognition) that will be added to an environemnt.
/// </summary>
/// <param name="sigma">The sigma environemnt this trainer will be assigned to.</param>
/// <returns>The newly created trainer.</returns>
private static ITrainer CreateMnistTrainer(SigmaEnvironment sigma)
{
IDataset dataset = Defaults.Datasets.Mnist();
ITrainer trainer = sigma.CreateTrainer("mnist-trainer");
trainer.Network = new Network();
trainer.Network.Architecture = InputLayer.Construct(28, 28)
+ DropoutLayer.Construct(0.2)
+ FullyConnectedLayer.Construct(1000, activation: "rel")
+ DropoutLayer.Construct(0.4)
+ FullyConnectedLayer.Construct(800, activation: "rel")
+ DropoutLayer.Construct(0.4)
+ FullyConnectedLayer.Construct(10, activation: "sigmoid")
+ OutputLayer.Construct(10)
+ SoftMaxCrossEntropyCostLayer.Construct();
trainer.TrainingDataIterator = new MinibatchIterator(100, dataset);
trainer.AddNamedDataIterator("validation", new UndividedIterator(Defaults.Datasets.MnistValidation()));
trainer.Optimiser = new AdagradOptimiser(baseLearningRate: 0.02);
trainer.Operator = new CudaSinglethreadedOperator();
trainer.AddInitialiser("*.weights", new GaussianInitialiser(standardDeviation: 0.1));
trainer.AddInitialiser("*.bias*", new GaussianInitialiser(standardDeviation: 0.05));
trainer.AddLocalHook(new ValueReporter("optimiser.cost_total", TimeStep.Every(1, TimeScale.Iteration), reportEpochIteration: true)
.On(new ExtremaCriteria("optimiser.cost_total", ExtremaTarget.Min)));
trainer.AddLocalHook(new RunningTimeReporter(TimeStep.Every(1, TimeScale.Epoch), 4));
return(trainer);
}
private static void SampleMnist()
{
SigmaEnvironment sigma = SigmaEnvironment.Create("mnist");
sigma.SetRandomSeed(0);
IDataset dataset = Defaults.Datasets.Mnist();
ITrainer trainer = sigma.CreateTrainer("mnist-trainer");
trainer.Network = new Network();
trainer.Network.Architecture = InputLayer.Construct(28, 28)
+ DropoutLayer.Construct(0.2)
+ FullyConnectedLayer.Construct(1000, activation: "rel")
+ DropoutLayer.Construct(0.4)
+ FullyConnectedLayer.Construct(800, activation: "rel")
+ DropoutLayer.Construct(0.4)
+ FullyConnectedLayer.Construct(10, activation: "sigmoid")
+ OutputLayer.Construct(10)
+ SoftMaxCrossEntropyCostLayer.Construct();
trainer.TrainingDataIterator = new MinibatchIterator(100, dataset);
trainer.AddNamedDataIterator("validation", new UndividedIterator(Defaults.Datasets.MnistValidation()));
//trainer.Optimiser = new GradientDescentOptimiser(learningRate: 0.01);
//trainer.Optimiser = new MomentumGradientOptimiser(learningRate: 0.01, momentum: 0.9);
trainer.Optimiser = new AdagradOptimiser(baseLearningRate: 0.02);
trainer.Operator = new CudaSinglethreadedOperator();
trainer.AddInitialiser("*.weights", new GaussianInitialiser(standardDeviation: 0.1));
trainer.AddInitialiser("*.bias*", new GaussianInitialiser(standardDeviation: 0.05));
trainer.AddLocalHook(new ValueReporter("optimiser.cost_total", TimeStep.Every(1, TimeScale.Iteration), reportEpochIteration: true)
.On(new ExtremaCriteria("optimiser.cost_total", ExtremaTarget.Min)));
var validationTimeStep = TimeStep.Every(1, TimeScale.Epoch);
trainer.AddHook(new MultiClassificationAccuracyReporter("validation", validationTimeStep, tops: new[] { 1, 2, 3 }));
for (int i = 0; i < 10; i++)
{
trainer.AddGlobalHook(new TargetMaximisationReporter(trainer.Operator.Handler.NDArray(ArrayUtils.OneHot(i, 10), 10), TimeStep.Every(1, TimeScale.Epoch)));
}
trainer.AddLocalHook(new RunningTimeReporter(TimeStep.Every(10, TimeScale.Iteration), 32));
trainer.AddLocalHook(new RunningTimeReporter(TimeStep.Every(1, TimeScale.Epoch), 4));
trainer.AddHook(new StopTrainingHook(atEpoch: 10));
sigma.PrepareAndRun();
}