Hi,there is error showing that the variable is varying.Someone help me plz

for i=1:M 
 str=strcat('C:\Users\Dhanya Francis\Desktop\Project\',int2str(i),'.jpg');
 eval('img=imread(str)');
 subplot(ceil(sqrt(M)),ceil(sqrt(M)),i)
 imshow(img)
  if i==2        
      title('Training set','fontsize',18)    
  end
  drawnow; 
  [irow,icol]=size(img);
  img(irow,icol) ;
  temp=reshape(img,irow*icol,1);
  S=horzcat(S,temp);

[Image Analyst]

http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup

S and temp don't have the same number of rows. In fact, S was never even defined before you tried to use it, or at least if it was, you didn't show that code.

Answer 1

[Walter Roberson]

Do not use eval!

str = fullfile('C:\Users\Dhanya Francis\Desktop\Project\', sprintf('%d.jpg', i));
img = imread(str);

Your line

    [irow,icol]=size(img);

is incorrect for any RGB image, and .jpg are almost always RGB images.

http://www.mathworks.com/help/matlab/ref/size.html

[d1,d2,d3,...,dn] = size(X), for n > 1, returns the sizes of the dimensions of the array X in the variables d1,d2,d3,...,dn, provided the number of output arguments n equals ndims(X). If n does not equal ndims(X), the following exceptions hold:

n < ndims(X) di equals the size of the ith dimension of X for 0<i<n, but dn equals the product of the sizes of the remaining dimensions of X, that is, dimensions n through ndims(X).