App Designer error Undefined function 'mtimes' for input arguments of type 'cell'.

I'm trying to reshape a 8x1280 matrix by stacking N columns

A %is some 8x1280 matrix
N = 128; 
NewA = reshape(A, N*8, []); % 1024x10 matrix (128 cols of A stacked on top of each other x10)

the code above works just fine in my code.m file,but this error msg appears when I run the same code in the App Designer

Undefined function 'mtimes' for input arguments of type 'cell'.

So is there another way to reshape the matrix without using reshape function?!

*Edit

I tried this ,but gives error"Index in position 2 exceeds array bounds."

A=rand(8,1280);
NewA=[];
for n1=1:10
   for n2=1:128
      NewA(:,n1)=[ NewA(:,n1); A(:,n2)]; 
   end
end

Answer 1

[Steven Lord]

Those commands work for me with a simple matrix. Show us the full and exact text of the error message you receive (include all the text displayed in red, and if there is any text displayed in orange show us that as well.

My suspicion is that while you think N is the scalar 128, it is in fact {128}. To confirm or rebut my suspicion, add the following line of code immediately before your reshape call and show us the output. [If your reshape call from your post is a simplified version, replace the A and N pieces with the names of the actual variables you use in your call.]

whos A N

[Omar Ashraf]

OMG I can't thank you enough!

I was actually reading N from a txt file, and didn't know that it was read as a cell instead of a scalar!