k=10;
cp = classperf(groups);
cvFolds = crossvalind('Kfold', groups, k);
for i = 1:k
 testIdx = (cvFolds == i);                %# get indices of test instances
 trainIdx = ~testIdx;                     %# get indices training instances
 svmModel = fitcsvm(data(trainIdx,:), groups(trainIdx),
'Standardize',true,'KernelFunction','RBF','KernelScale','auto');
 pred = predict(svmModel, meas(testIdx,:));
 cp = classperf(cp, pred, testIdx);