Shor Algorithm for prime factoring

Hi, i'm trying to run this code on Matlab R2020a regarding Shor's Algorithm for prime factoring and i'm getting an error saying that the function 'bigmod' is unrecognized. What should i do to make it work properly? Thanks

https://www.mathworks.com/matlabcentral/fileexchange/72945-shor-algorithm-for-prime-factoring

Unrecognized function or variable 'bigmod'.

Error in shor>order_qstyle (line 62)

f(k) = bigmod(q,k,N);

Error in shor (line 18)

k = order_qstyle(q,N); % search order q^k mod N using fft

Error in shor (line 14)

factors = cat(2, factors, shor(teiler), shor(N./teiler));

Answer 1

[Stephen23]

You need to download bigmod from here:

www.mathworks.com/matlabcentral/fileexchange/7908-big-modulo-function

(the link is given inside the shor function that you are using, you just need to scroll down to the end. I agree that this dependency should be better documented).

[Renan Poço]

Thank you Stephen