Suppose result_conv is of size 2-by-2 and x is 1 and y is 1. Then all the if conditions are met, so the for loops are executed. Then the first iteration of the inner loop has i=-1 and j=-1, so y+j=0 and x+i=0. That means the code will try to access result_conv(0,0), which is in error because indexing starts with 1 in MATLAB.
% Suppose result_conv is of size 2-by-2 and x is 1 and y is 1
if (x <= (size(result_conv,1)-1)) ... % 1 <= 1
&& (y <= (size(result_conv,1)-1)) ... % 1 <= 1
&& (x >= 1) ... % 1 >= 1
&& (y >= 1) % 1 >= 1
% ...
for i=-1:1
for j=-1:1
if i ~= 0
% the first time here, i=-1 and j=-1, so
% y+j=0 and x+i=0, so result_conv(y+j,x+i) is
% result_conv(0,0), an error
c10(j+2,i+2)=i*log(result_conv(y+j, x+i));
% ...
end
% ...
end
end
end
Perhaps the 3rd and 4th conditions in the if statement should be x >= 2 && y >= 2?
Or equivalently, if x and y are always integers (which they should be since they're being used for indexing), perhaps this is more clear:
if x < size(result_conv,1) ...
&& y < size(result_conv,1) ...
&& x > 1 ...
&& y > 1
