偏微分差分四种格式的matlab程序(共5页).doc

精选优质文档-倾情为你奉上偏微分差分四种格式的matlab程序（1）Lax-Fridrichs格式function u = LaxFridrichs(a,dt,n,x1,x2,m)format long;h = (x2-x1)/(n-1);for j=1:(n+2*m) u0(j) =U(x1+(j-m-1)*h);end u1 = u0;for k=1:m for i=k+1:n+2*m-k u1(i) = -(dt/h)*a*(u0(i+1)-u0(i-1)/2+(u0(i+1)+u0(i-1)/2; end u0 = u1;endx=0.01:0.01:n/100; u = u1(m+1):(m+n);plot(x,u,r); axis(0 1 -0.5 1.5);hold ony=1.*(x0.5);plot(x,y,c)title(Lax-Fridrichs)format sho