palu.m

来自「数值线性代数的Matlab应用程序包 共13个程序函数」· M 代码 · 共 28 行

function [P,L,A]=PALU(A)
[m,n]=size(A);
L=eye(m);
P=eye(m);
for k=1:m-1
    for i=k+1:m
        t=0;
        if abs(A(i,k))>abs(A(k,k))
            t=k;
        end
        if t~=0
            temp=A(k,k:m);
            A(k,k:m)=A(i,k:m);
            A(i,k:m)=temp;
            temp=L(k,1:k-1);
            L(k,1:k-1)=L(i,1:k-1);
            L(i,1:k-1)=temp;
            temp=P(k,:);
            P(k,:)=P(i,:);
            P(i,:)=temp;
        end
    end
    for j=k+1:m
        L(j,k)=A(j,k)/A(k,k);
        A(j,k:m)=A(j,k:m)-L(j,k)*A(k,k:m);
    end
end