Matlab code error - matlab code error - Subscript indices must either be real positive integers or logicals

I am getting an error in a matlab code...

Here is my matlab code....

a = 0;
b = 1000;
ftype ='function estimation';
y1 = [];
y2 = [];
y3 = [];
y6 = [];

p=a+(b-a)*lhsdesign(100,2);

s = length(p(:,1));

ydata = -log(ydata);
ytest = -log(ytest);

for k = 1:10

for n = 1:s
gam = p(n,1);
sig2 = p(n,2);

[alpha1,b1] = trainlssvm({xdata,ydata,ftype,gam,sig2,'RBF_kernel'});

tic

ysvm = simlssvm({xdata,ydata,ftype,gam,sig2,'RBF_kernel','preprocess'},{alpha1,b1},xtest);

toc

y4 = toc;
A = ysvm-ytest;                           
y5 = (sum(A.*A))/5000;
*y6 = corr(ytest,ysvm);*

   y4 = [y1; y4];
   y5 = [y2; y5];
   y6 = [y3; y6];

y1 = y4; 
y2 = y5;
y3 = y6;
end

gam = p(:,1);
sig2 = p(:,2);
time = y4;
mse = y5;
corr = y6;

xyz = [gam sig2 time mse corr];
xyz = sortrows(xyz,4);
xyz = xyz(1,:);
gam = xyz(1,1);
sig2 = xyz(1,2);
time = xyz(1,3);
mse = xyz(1,4);
corr = xyz(1,5);

if (mse <= 0.00001)

      exit;

else

      mse = mse;

end

if (gam <= 0)

      gam = 1000;
  else

      gam = gam;

end

mu = [gam sig2];
SIGMA = [0.1 0; 0 0.1];
p = mvnrnd(mu,SIGMA,100);
s = length(p(:,1));

y1 = [];
y2 = [];
y3 = [];
end

I am getting the error in line

y6 = corr(ytest,ysvm)

Please help...

Answer 1

[Mickaël Tits]

Actually the problem is simply that you used "corr" as the name of a variable, so when you type

y6 = corr(ytest,ysvm)

you don't really call the function, but look in your variable corr at indices ytest and ysvm (that a probably not integers, so the error).

Answer 2

[Walter Roberson]

Please use

which corr

to verify that there is a corr() routine. corr() is part of the Statistics Toolbox, not part of basic MATLAB.