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For loop Issue, Loops, Row Col Indexing Issue

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rizwan
rizwan on 7 Apr 2015
Closed: MATLAB Answer Bot on 20 Aug 2021
Experts, I stuck in the logic of for loop,
load 'D:\MS\Research\Classification Model\Research Implementation\test.mat'; % loading test data i.e cp
[rI,cI] = size(cp);% size of test data
resultantImage = zeros(rI,cI); % image to store classified pixels
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
for i=1:length(resultantImage)
classes = svmclassify(SVMModel,cp(rI(i),cI(i)),'Showplot', true);
if (classes == 'Y')
resultantImage(rI(i),cI(i)) = 1;
classes = 1;
else if (classes == 'N')
resultantImage(rI(i),cI(i)) = 0;
end
end
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
In the above for loop i want to extract the value from 'cp' variable and pass it to classifier for classification once i have pixel classified as 'Y' or 'N', i use the row col index of the pixel and store either 1 or 0 at the same row col index of resultant image. I have written the above logic but resultant image is not getting populated with 1 or 0 values it remains zeros array!!!!!!!!! Please help

Answers (1)

Ingrid
Ingrid on 7 Apr 2015
This does not seem to be a problem with the for-loop. Are you sure that the SVMM model is correct and that it gives as output 'Y' and 'N' as possible groups? You can check for this by not using an if but a switch so in your case:
for i=1:length(resultantImage)
classes = svmclassify(SVMModel,cp(rI(i),cI(i)),'Showplot', true);
switch classes
case 'Y'
resultantImage(rI(i),cI(i)) = 1;
case 'N'
resultantImage(rI(i),cI(i)) = 0;
otherwise
error('Not classified in the correct class')
end
end
I always use the switch option when working with string variables as it makes the code more clear to read even if there are no problems in the implementation
  4 Comments
rizwan
rizwan on 11 Apr 2015
Thanks,
But when i did this it prompts
The number of columns in TEST and training data must be equal.
Please help

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