How to use Grid search to find the optimal hyperparameters ?

% Train the classifier

knn = ClassificationKNN.fit(Xtrain,Ytrain,'Distance','seuclidean');

Answer 1

[Mohith Kulkarni]

Use the 'OptimizeHyperparameters' Name-Value pair argument to specify the Parameters to optimize when creating the 'ClassificationKNN' model using 'fitcknn'. Use the 'HyperparameterOptimizationOptions' to specify the Optimizer for the model. Refer the code below.

Mdl = fitcknn(X,Y,'OptimizeHyperparameters','auto',...
    'HyperparameterOptimizationOptions',...
    struct('Optimizer','gridsearch'))

You can use this model for fitting the data with the specified optimization options.

Refer the documention of fitcknn and ClassificationKNN for more information on the Name-Value pair arguments.