how to fix this error 'interp2'

imshow(matrix(:,:,1))
%identify axes
[x y] = ginput(2);

% preallocate matrices
cog = zeros(size(matrix,3),1);
%cog
% loop start
for i = 1:size(matrix,3)
    I = matrix(:,:,i);
    
    n = ceil(norm([diff(x), diff(y)]));  
    
    test = interp2(I, linspace(x(1), x(2),n), linspace(y(1), y(2),n));
    
    cog(i) = sum((1:length(test)).*test')/sum(test);
    % loop end
end

scog = (cog - min(cog)) / (max(cog) - min(cog));

Answer 1

[Matt J]

Because your first argument to interp2 is a matrix while the second is a scalar.

[BA]

it's a typo, but still have the problem. Any suggestions?

[Matt J]

it's a typo,

You haven't fixed the typo in your post, so we don't know what your current code is. In addition to that, I suggest you provide us the means to run the code, in particular by attaching "matrix" in a .mat file.

[BA]

.mat file is huge one (MRI video)

This is the error I get:

error: =: nonconformant arguments (op1 is 1x1, op2 is 1x28)

[Matt J]

We only need matrix(:,:,1) to trigger the error.

[Matt J]

This is the error I get:

That is not what a Matlab error message looks like. As a routine matter, you should copy/paste error output messages in their entirety.

[Steven Lord]

From these questions: 1, 2 it sounds like the poster is using Octave rather than MATLAB. If that's the case, that would explain the difference in the appearance of the error message.