possionequationjacobi.m

Jacobi求解线性方程组、possison方程

% n=3; 
clear all
clc
l=3;
nl=2^l+1;
h=1/(nl-1);
t=nl*nl;
%生成矩阵A
a=repmat([-1 -1 4 -1 -1],t,1);
Al=spdiags(a,[-nl -1 0 1 nl],t,t);
for i=1:nl-1
    Al(i*nl,i*nl+1)=0;
    Al(i*nl+1,i*nl)=0;
end  
% Al=h^(-2)*Al;
f=zeros(t,1);
f(1)=1;
for i=2:t
    f(i)=f(i-1)*(-1);
end