Can't add matrix with same dimension, pulls error...

so far, i have this code

function polamodel=meanmodel(pola)
    [lod,hid] = wavefilter('jpeg9.7','d');

      pass=1;

      [cc,sc]=wavedec2(pola{1}{2}{1},pass,lod,hid);
      s=size(cc);

      for i=1:62
          sum=zeros(1,s(2));
          for j=1:30
              [c,s]=wavedec2(pola{i}{2}{j},pass,lod,hid);
              sum=sum+c;
          end
          pola{i}{3}=sum ./30;
      end
      polamodel=pola;
  end

but then i have this error :

??? Error using ==> plus
Matrix dimensions must agree.

Error in ==> meanmodel at 15
            sum=sum+c;

Error in ==> main at 52
pola=meanmodel(pola);

that telling me the line sum=sum+c have an error in it. It's very weird because I'm very sure variable c and sum have a same dimension (I tried to figure it out with size(c) and size(sum)). I assume the error comes with variable c.

Anybody have an idea???

Answer 1

[per isakson]

Use the debugger. Execute in the command window

    dbstop if error

and run your function

    polamodel=meanmodel(pola);

Matlab will stop at line 15. Inspect the values of the variables i, j, c.

There are buttons in the toolbar to operate the debugger.

Return here if you don't find the reason for the error.

PS. I'm not so sure!

Answer 2

[Walter Roberson]

People who use "sum" as the name of a variable always run into code problems when they do so.