How can I calculate P

Hi, below is the function where I need to solve P, but when I used the code below, it gave me the wrong P. Is there any way I can modify this?

function [L, U, P] = lu_pp(A)

n = length(A);

U = zeros(n,n);

L = zeros(n,n);

P = zeros(n,n);

for k = 1:n

U(k,k)= A(k,k);

for i = k+1:n

L(i,k) = A(i,k)./U(k,k);

U(k,i) = A(k,i);

end

for i = k+1:n

for j = k+1:n

A(i,j) = A(i,j)-L(i,k)*U(k,j);

end

end

end

P = L*U*inv(A);

end

[Walter Roberson]

No documentation about what the input is, or what the output is expected to be, so we as outsiders have to guess that your code defines what it is intended to do, and that therefore your code is perfect the way it is.