Use Parfor error:Subscripted assignment dimension mismatch

Hi, I came across the following errors when running the parallel codes. If I use 'parfor',matlab will appear this error:Subscripted assignment dimension mismatch. parfor j=1:1000

But if I use 'for',this error will not appear.I'm very confused about this problem.Can anyone help me,please? Thanks.

The code:

X=load('x.txt');
Y=load('y.txt');

XY=[Y,X];

[a,b]=size(XY);

N=10;

inOption.tol = 1e-6;

inOption.maxit = 50;

inOption.bctype = 1; 

inOption.maxcmp = 50; 
inOption.maxvar = a/2;
ptype='ebtz';
inOption.ptype = ptype;

inOption.delta = 0.1;
msc = [2 3 0:0.1:1];

parfor j=1:50

      B=zeros(0,b);
      for i=1:a
          B=[B;XY(randi([1,a]),:)];
      end
      x=B(:,2:end);
      y=B(:,1);
      x=Standardize(x);
      y=Standardize(y);
      ret=POCREPath(y,x,inOption);
      for k=1:13
          fRes=SelectModel(a,ret,msc(k)); 

          lambda=fRes.lambda;
      end 

      retRes{:,j}=POCRE(y,x,lambda,inOption);

end

[Edric Ellis]

What is the output of POCRE? Does it help to pre-allocate "retRes" before the start of the loop?

[Kaibing Yang]

Output of POCRE is a struct.I've solve the problem.I changed retRes{:,j} to retRes(:,j) ,and the error will not appear.Thank you !