Error-Performing cross validation rbf

I have a set of code 

load fisheriris

   indices = crossvalind('Kfold',species,10);

    group1=[1;2;2;1;1;2;1;2;1;2]

   group = cellstr(num2str(group1))

   cp = classperf(species); 

for i = 1:10
     test = (indices == i); train = ~test;

net = newrb(meas(:,1),group1);

b=meas(:,3);

   Y=sim(net,b);

classperf(cp,Y,test); 

end

but i get error ,please help

Error using ==> classperf at 163
When class labels of the CP object is a cell array of strings and
the classifier output is a numeric array, it must contain valid
indices of the class labels or NaNs for inconclusive results.

Error in ==> Untitled at 13
classperf(cp,Y,test)

[Oleg Komarov]

What's crossvalind?

[FIR]

i did not understand as u said