My code is not working and i cannot figure out why not?

Question

daniel choudhry 2020-10-7

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/606711-my-code-is-not-working-and-i-cannot-figure-out-why-not

回答： Walter Roberson 2020-10-7

I need to put this into my command window in order to generate my answer d, but my d is not working and i dont know how to fix my d inside my code.

>>rand('seed',1)
>>A = rand(10,10);
>>d = my_det(A)
>>dd = det(A)
>>abs(d-dd)/abs(dd)

function d = my_det(A)
n = size(A,1);
s = 0;
% Gauss_PP:
for k = 1:n-1
    
    r = k;
  
     
     for j = k+1:n
         if abs(A(j,k))> abs(A(k,k))
             T=A(k,:);
             A(k,:)=A(j,:);
             A(j,:)=T;
         end
     end
     
     while A(r,k) == 0 && r <= n
         r=r+1;
     end
     
     if r > n+1
         disp('A is not invertible');
         break
     else
         if r ~= k
             s = s+1;
             t=A(k,:);
             A(k,:)=A(s,:);
             A(s,:)=t;
         end
     end
     d = (-1)^s;;
 if A(n,n)< n*10^(-15)
     disp('A is not invertible');
     
     return
 end
end