how to get SURF feature vector values of multiple images

Hello, i have extracted surf features from multiple images using the following code.But only the last image feature value is stored in the feature variable used in the code. how to get all the feature vector values..

Thank you... Code:

        srcFiles = dir('F:\MTECH\MATLAB\Begin\photos\*.jpg');  

        for i = 1 : length(srcFiles)

       filename = strcat('F:\MTECH\MATLAB\Begin\photos\',srcFiles(i).name);

       I1 = rgb2gray(imread(filename));

       points1 = detectSURFFeatures(I1);

       [features2, valid_points1] = extractFeatures(I1, points1);

       figure; imshow(I1); hold on;

       plot(valid_points1.selectStrongest(10),'showOrientation',true);

       columnvector = rand(1,64); 

       finalFeature = sum(columnvector(:));

       sprintf('%s %d','finalFeature = ' , finalFeature)

    end

Answer 1

[Walter Roberson]

       finalFeature(i) = sum(columnvector(:));

       sprintf('%s %d','finalFeature = ' , finalFeature(i))

[KDR]

sir.. Now each image is represented with unique surf feature value. So can it be used for input to KNN classification for training set??

[Deeksha Saxena]

I didn't understand your answer. Actually I also need to find the surf features for an image. In your code, "columnvector = rand(1,64);", in this line, you created a column with random values and than next you got the sum of this as your final features. how does this represent the final features? can you please explain?

[Walter Roberson]

Good question about why they use rand() here, especially creating a random row vector instead of a random column vector like the variable names suggest.

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[Deeksha Saxena]

row vector or column vector, doesn't matter. my question was why created an vector of random values and using the sum of that as final features. why?? I didn't understand the logic behind this.

[Walter Roberson]

I do not know why they did that. Unfortunately that was 7 months ago, and they did not leave contact information.

[Siti Suhaila]

I'm also a bit confused with rand(). It shows that my final features resulted differently every time we run the code.

[Walter Roberson]

I think the line with the rand() is "dummy code", put in to allow the framework to be developed but intended for replacement later.