Calculate cross validation in Generalized Linear Model

This link provides example of using cvpartition and classification class to find cross validation of fisheriris data set. How is it possible to find the cross validation error for other canonical function , for example the predict for the Generalized Linear Model. The snippet of code for cross-validation of fisheriris dataset is:

load('fisheriris');
y = species;
X = meas;
cp = cvpartition(y,'k',10); % Stratified cross-validation

classf = @(XTRAIN, ytrain,XTEST)(classify(XTEST,XTRAIN,...
ytrain));

cvMCR = crossval('mcr',X,y,'predfun',classf,'partition',cp)
cvMCR =
    0.0200