First time matlab user problem Matrix dimensions must agree?

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Azfar
Azfar on 23 Apr 2013
Hi,
I'm a first time matlab user and I've run into a bit of a problem I keep getting an error. Here is my sequence of codes:
derivefilter(FREQSPEC,600);
handle =
1
y =
173.0011
ans =
173.0011
filtering=applyfilter(pic1,ans);
Error using .*
Matrix dimensions must agree.
Error in applyfilter (line 3)
filteredspec=imgspec.*filter;
Here is the script "applyfilter":
function y=applyfilter(img,filter)
imgspec=fftshift(fft2(img));
filteredspec=imgspec.*filter;
y=real(ifft2(fftshift(filteredspec)));
Any help would be appreciated thanks.

Accepted Answer

Image Analyst
Image Analyst on 23 Apr 2013
What does derivefilter() return? You're not accepting any matrix for the filter that you can then pass in to applyfilter() instead of ans. You may need to have something like
myFilter = derivefilter(FREQSPEC,600);
filtering=applyfilter(pic1, myFilter);
but we can't tell until we know what's inside derivefilter().
  6 Comments
Azfar
Azfar on 24 Apr 2013
Thanks for your help, re-sizing the pic1 variable resolved the issue.

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More Answers (2)

Leah
Leah on 23 Apr 2013
imgspec and filter must have the same dimension to do a element-wise multiplications
size(imspec)
size(filter)

Jan
Jan on 23 Apr 2013
Edited: Jan on 23 Apr 2013
Your code would be easier to read, if you spend the time for reading the manuals for this forum and format the code properly.
It looks like:
imgspec .* filter
cannot work, because the array sizes do not match. This is surprising, because the value of filter seems to be a scalar.
Using ans explicitly is a bad idea, because this value is very volatile and debugging can change the value. filter is not a good choice also, because this is a name of an important built-in function.
  2 Comments
Jan
Jan on 24 Apr 2013
@Azfar: Then it is the job of your supervisor to find the solution. We cannot guess how this should be fixed, because all we see is the failing code. To find a solution, one has to know the intention of the code, but wrong code cannot carry this kind of information.

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