Help with indexing error

Question

William_M 2018-6-2

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/403711-help-with-indexing-error

回答： Walter Roberson 2018-6-2

function B = Ecomp(e,f)
%Compares 2 elements of equal length (unfactored) in
%Sn and sees if theyre the same, i.e cyclic permutations of each other.
B='TRUE';
k=0;
n=length(e);
for i = 1:n
    if f(i) == e(1)
        k=i;
    end
end
    for j = 1:n-1
        if f(mod(k+j,n)) ~= e(j+1) 
            B='FALSE';
            return
        end
    end
end

This function is supposed to compare two vectors and see if they are cyclic permutations of each other. For example, Ecomp([1,2,3,4],[4,1,2,3]), should return 'TRUE', however when I input this the error that I get is:

>> Ecomp([1,2,3,4],[4,1,2,3])
Subscript indices must either be real positive integers or logicals.
Error in Ecomp (line 13)
        if f(mod(k+j,n)) ~= e(j+1)

I can't see why as my indexing starts from 1, any help much appreciated.