fun2.m

关于一的微分方程数值解,一维波动方程初边值问题Crank-Nicholson格式,及追赶法

function A=fun2(t,h,T)
%上机实习二隐式格式;
r=t^2/h^2;
D=100;E=5000;F=3000;L=1;
N=T/t+2;
J=L/h+2;
A(2,J)=0;         %另第一,二行为零
a(1:J-2)=-D*r;
b(1:J-2)=1+2*D*r;
c(1:J-2)=-D*r;
for i=3:N
    A(3,1)=0;
    A(3,end)=0;
    A(3,2:J-1)=2*A(2,2:J-1)-A(1,2:J-1);
    for k=1:J-2
        A(3,k+1)=A(3,k+1)+t^2*(E*(k)*h*(L-(k)*h)+F);
    end
    A(3,2:J-1)=(zuigan(a,b,c,A(3,2:J-1)'))';      %追赶法
    A(1,:)=A(2,:);
    A(2,:)=A(3,:);
end