internal static Optimizer GetOptimizer(NeuralNetworkSettingsEntity s)
{
switch (s.Optimizer)
{
case TensorFlowOptimizer.Adam:
return(tf.train.AdamOptimizer((float)s.LearningRate, (float)s.LearningEpsilon));
case TensorFlowOptimizer.GradientDescentOptimizer:
return(tf.train.GradientDescentOptimizer((float)s.LearningRate));
default:
throw new InvalidOperationException("Unexpected Learner");
}
}
internal static Learner GetInitializer(IList <Parameter> parameters, NeuralNetworkSettingsEntity s)
{
var vector = new ParameterVector((ICollection)parameters);
switch (s.Learner)
{
case NeuralNetworkLearner.Adam: return(CNTKLib.AdamLearner(vector,
s.LearningRate.ToTrainParam(),
s.LearningMomentum?.ToTrainParam(),
s.LearningUnitGain ?? false,
s.LearningVarianceMomentum?.ToTrainParam()));
case NeuralNetworkLearner.AdaDelta:
return(CNTKLib.AdaDeltaLearner(vector,
s.LearningRate.ToTrainParam()));
case NeuralNetworkLearner.AdaGrad:
return(CNTKLib.AdaGradLearner(vector,
s.LearningRate.ToTrainParam()));
case NeuralNetworkLearner.FSAdaGrad:
return(CNTKLib.FSAdaGradLearner(vector,
s.LearningRate.ToTrainParam(),
s.LearningMomentum?.ToTrainParam(),
s.LearningUnitGain ?? false,
s.LearningVarianceMomentum?.ToTrainParam()));
case NeuralNetworkLearner.RMSProp:
return(CNTKLib.FSAdaGradLearner(vector,
s.LearningRate.ToTrainParam(),
s.LearningMomentum?.ToTrainParam(),
s.LearningUnitGain ?? false,
s.LearningVarianceMomentum?.ToTrainParam()));
case NeuralNetworkLearner.MomentumSGD:
return(CNTKLib.MomentumSGDLearner(vector,
s.LearningRate.ToTrainParam(),
s.LearningMomentum?.ToTrainParam(),
s.LearningUnitGain ?? false));
case NeuralNetworkLearner.SGD:
return(CNTKLib.SGDLearner(vector,
s.LearningRate.ToTrainParam()));
default:
throw new InvalidOperationException("Unexpected Learner");
}
}
private DeviceDescriptor GetDevice(NeuralNetworkSettingsEntity nnSettings)
{
if (!nnSettings.Device.HasText())
{
return(DeviceDescriptor.UseDefaultDevice());
}
var dev = DeviceDescriptor.AllDevices().FirstOrDefault(a => a.AsString() == nnSettings.Device);
if (dev == null)
{
return(DeviceDescriptor.UseDefaultDevice());
}
return(dev);
}
