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c#pythoncntk

Learners in CNTK C# API

I am using C# CNTK 2.2.0 API for training. I have installed Nuget package CNTK.CPUOnly and CNTK.GPU.

I am looking for following learners in C#. 1. AdaDelta 2. Adam 3. AdaGrad 4. Neterov

Looks like Python supports these learners but C# package is not showing them.

I can see only SGD and SGDMomentun learners in C# there.

Any thoughts, how to get and set other learners in C#. Do I need to install any additional package to get these learners?

Appreciate your help.

Solution

  • The CNTKLib class in the CNTK namespace provides several learners, even not all of those you have listed. I list them in the following without their overloads.

    public static Learner SGDLearner(ParameterVector parameters, TrainingParameterScheduleDouble learningRateSchedule);
public static Learner MomentumSGDLearner(ParameterVector parameters, TrainingParameterScheduleDouble learningRateSchedule, TrainingParameterScheduleDouble momentumSchedule);
public static Learner FSAdaGradLearner(ParameterVector parameters, TrainingParameterScheduleDouble learningRateSchedule, TrainingParameterScheduleDouble momentumSchedule);
public static Learner AdamLearner(ParameterVector parameters, TrainingParameterScheduleDouble learningRateSchedule, TrainingParameterScheduleDouble momentumSchedule);
public static Learner AdaGradLearner(ParameterVector parameters, TrainingParameterScheduleDouble learningRateSchedule);
public static Learner RMSPropLearner(ParameterVector parameters, TrainingParameterScheduleDouble learningRateSchedule, double gamma, double inc, double dec, double max, double min);
public static Learner AdaDeltaLearner(ParameterVector parameters, TrainingParameterScheduleDouble learningRateSchedule);

    You easily can access them like the following:

    using CNTK;
CNTKLib.AdaDeltaLearner([...])

    This was done with the GPU version of CNTK 2.2. Maybe it is different with the CPU version.