function [C, sigma] = dataset3Params(X, y, Xval, yval)
%EX6PARAMS returns your choice of C and sigma for Part 3 of the exercise
%where you select the optimal (C, sigma) learning parameters to use for SVM
%with RBF kernel
%   [C, sigma] = EX6PARAMS(X, y, Xval, yval) returns your choice of C and 
%   sigma. You should complete this function to return the optimal C and 
%   sigma based on a cross-validation set.
%

% You need to return the following variables correctly.
C = 1;
sigma = 0.3;

% ====================== YOUR CODE HERE ======================
% Instructions: Fill in this function to return the optimal C and sigma
%               learning parameters found using the cross validation set.
%               You can use svmPredict to predict the labels on the cross
%               validation set. For example, 
%                   predictions = svmPredict(model, Xval);
%               will return the predictions on the cross validation set.
%
%  Note: You can compute the prediction error using 
%        mean(double(predictions ~= yval))
%

Carr = [0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30];
sigmaArr = [0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30];

% bestC = 0;
% bestSigma = 0;

model= svmTrain(X, y, C, @(x1, x2) gaussianKernel(x1, x2, sigma));
predictions = svmPredict(model, Xval);
minErr = mean(double(predictions~=yval));

for c = 1:length(Carr)
    for s = 1:length(sigmaArr)
        model= svmTrain(X, y, Carr(c), @(x1, x2) gaussianKernel(x1, x2, sigmaArr(s)));
        predictions = svmPredict(model, Xval);
        err = mean(double(predictions~=yval));
        if(err<=minErr)
            C = Carr(c);
            sigma = sigmaArr(s);
            minErr = err;
        end;
    end;
end;





% =========================================================================

end

1094401996
github-repos/MATLAB/1094401996-machine-learning-coursera/machine-learning-coursera-e53d1021a08b0f2ab7e0840d9807ab14e24ea9bb/problem_sets/ex6/dataset3Params.m
machine-learning-coursera
github-repos/MATLAB/1094401996-machine-learning-coursera
e53d1021a08b0f2ab7e0840d9807ab14e24ea9bb