guasspp1.m

高斯分解

function [ output_args ] = Gausspp( input_args )
%UNTITLED1 Summary of this function goes here
%   Detailed explanation goes here
A=[3   -5    6   4    -2    -3     8
   1    1   -9   15    1    -9     2
   2   -1    7    5    -1    6    11
   -1   1    3    2     7    -1    -2
    4   3   1    -7     2     1     1
    2   9   -8    11    -1    -4   -1
    7   2   -1     2     7    -1   9];
b=[11;2;29;9;5;8;25];

for i=1:6
    for k=i:6
        if abs(A(k,i))>=abs(A(k+1,i))
            a=A(k,:);
            A(k,:)=A(k+1,:);
            A(k+1,:)=a;       
            c=b(k);
            b(k)=b(k+1);
            b(k+1)=c;
            
        end 
    end
    d=A(k+1,:);
    A(k+1,:)=A(i,:);
    A(i,:)=d;
    e=b(k+1);
    b(k+1)=b(i);
    b(i)=e;
    
    for j=i+1:7
        b(j)=b(j)-b(i)*(A(j,i)/A(i,i));
        A(j,:)=A(j,:)-(A(j,i)/A(i,i))*A(i,:);   
    end
end
x(7)=b(7)/A(7,7);
c=0;
for m=6:-1:1
    c=c+A(m,m+1)*x(m+1);
    x(m)=(b(m)-c)/A(m,m);
end
    x