why do I receive "Index in position 1 is invalid. Array indices must be positive integers or logical values"

B=6E-5;
MAT=zeros(26,26);
for i=1:26
for i=j
MAT(i,j)=[D*B+REM]
end
end

Answer 1

[Daniel Pollard]

i and j in MATLAB both have the default value of the complex unit. When you say

for i = 1:26

you override this, so now i takes the value in that for loop.

When you say

for i = j

you then reset i to be equal to the complex unit again. This is not an integer or logical so cannot be used as an index. I supsect what you want to do is

B=6E-5;
MAT=zeros(26,26);
for ii = 1:26
    for jj = 1:26
        MAT(ii, jj)=[D*B+REM]
    end
end

Answer 2

[KSSV]

In MATLAB the indexing should be always positive integers and/ or logical.

A = rand(1,10) ; 
A(1)  % no error
A(10)  % no error
idx = A>0.5 
A(idx)   % no error 
A(1.5)   % error becuase 1.5 is not integer
A(-1)    % error neghative not allowed