error usibg cros valdation

i have a code

load fisheriris

groups=species;
cvFolds = crossvalind('kfold', groups, 10); %# get indices of 10-fold CV %# get indices of 10-fold CV
cp = classperf(groups);
for k=1:10
b = TreeBagger(10,meas,species,'oobpred','on');
cp = classperf(groups,b)

end

but i get error as

Error using TreeBagger/subsref (line 884)
Subscripting into TreeBagger using () is not allowed.

Error in classperf (line 219)
gps = varargin{1}(:);

Error in yass (line 10)
cp = classperf(groups,b)

please help