how to solve this error "Subscripted assignment dimension mismatch."

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Yussif M. Awelisah 2019-10-12

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评论： Guillaume 2019-10-15

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I tried looping through 231 samples of data but the error below occurs,

Subscripted assignment dimension mismatch.

Error in tvf_emd (line 132)

imf(nimf,:)=y(ind_remov_pad);

 if flag_stopiter
            for row_number = 1 : size(imf,1); 
            end
               
           imf(nimf,:)=y(ind_remov_pad);
            temp_x=temp_x - y(ind_remov_pad);
            break;

each Imf is supposed to be 50x 500 but due to the 231 data samples , the imf matrix multiplies to become 50 x 115500.

This causes the above error even though I tried looping through each sample.

Please I will be grateful for any help.

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Guillaume 2019-10-12

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I'm sorry to say that your code is a mess. First, fix the indentation (ctrl+I in the editor) and look at all the orange lines on the right of the editor that tells you of potential problems. Then, there's the lack of comments that explain the overall aim of the code.

But more important, there's all the stuff that doesn't make sense and the bugs. e.g:

if size(x,1) > 1 % convert to row vector
    for row_number = 1 : size(x,1)
    end
end

That comment is misleading, we have a loop that does nothing, it certain doesn't do any conversion to row vector. You may be tempted to remove that loop (and you should) but a side effect of the loop is that it creates the variable row_number and set it to the numbers of rows of the input, so really that code is equivalent to:

if size(x, 1) > 1
    row_number = size(x, 1);
end

It's important because row_number is used later on. And here is the first problem, if x is a row vector, row_number never gets created and your code will error with an 'undefined variable or function row_number' error. This is indeed the case with your 'one_matrix_data'. The whole logic of these four lines is completely broken.

There are many more problems (e.g. if your code were to succeed, on the first iteration row_number would be size(x, 1), on all the other iterations row_number would be MAX_IMF as a side effect of another do nothing loop) but the main issue is that your code appears to be designed to work with row vectors only but has bugs like the above that prevent it to do so.

One thing for sure, your code was never designed to work with matrices and yes you'll see the error you had if you pass it a matrix.

So you need to go over everything you've written and think about what your inputs are. Are they row vectors, column vectors or matrices. You can't use numel or length with matrices.

And use the debugger to step through your code and see what it's actually doing.

Yussif M. Awelisah 2019-10-15

please I do not understand exactly what the above statement means. Please in that case will my input value be the same as M ?

Please I wish you can help further?

Guillaume 2019-10-15

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tvf_emd is a function, therefore you must be calling it from some other code (the same code that actually imports your data), maybe it's a script. The loop is in that other code. The function itself should be unmodified, e.g.

%script or function, NOT tvf_emd.m
matcontent = load('Total matrix data..mat')
DS_DATA_ODD  = matcontent.DS_DATA_ODD;
out = zeros(50, size(DS_DATA_ODD, 2), size(DS_DATA_ODD, 1))
for row = 1:size(DS_DATA_ODD, 1)
    out(:, :, row) = tvf_emd(DS_DATA_ODD(row, :));
end