对流方程各种格式代码matlab

1、精选优质文档-倾情为你奉上对流方程偏微分方程的数值解法用迎风格式解对流方程function u = peYF(a,dt,n,minx,maxx,M)format long;h = (maxx-minx)/(n-1);if a>0    for j=1:(n+M)        u0(j) = IniU(minx+(j-M-1)*h);    endelse       for j=1:(n+M)

2、60;       u0(j) = IniU(minx+(j-1)*h);    endend   u1 = u0;for k=1:M    if a>0         for i=(k+1):n+M            u1(i) = -dt*a*

3、(u0(i)-u0(i-1)/h+u0(i);        end    else        for i=1:n+M-k            u1(i) = -dt*a*(u0(i+1)-u0(i)/h+u0(i);        end&#

4、160;   end    u0 = u1;endif a>0    u = u1(M+1):M+n);else    u = u1(1:n);endformat long;用拉克斯-弗里德里希斯格式解对流方程function u = peHypbLax(a,dt,n,minx,maxx,M)format long;h = (maxx-minx)/(n-1);for j=1:(n+2*M)        u0(

5、j) = IniU(minx+(j-M-1)*h);end u1 = u0;for k=1:M    for i=k+1:n+2*M-k        u1(i) = -dt*a*(u0(i+1)-u0(i-1)/h/2+(u0(i+1)+u0(i-1)/2;    end    u0 = u1;endu = u1(M+1):(M+n);format short;用拉克斯-温德洛夫格式解对流方程function u = peL

6、axW(a,dt,n,minx,maxx,M)format long;h = (maxx-minx)/(n-1);for j=1:(n+2*M)        u0(j) = IniU(minx+(j-M-1)*h);end u1 = u0;for k=1:M    for i=k+1:n+2*M-k        u1(i) = dt*dt*a*a*(u0(i+1)-2*u0(i)+u0(i-1)/2/h/h -

7、.                   dt*a*(u0(i+1)-u0(i-1)/h/2+u0(i);    end    u0 = u1;endu = u1(M+1):(M+n);format short;用比姆-沃明格式解对流方程function u = peBW(a,dt,n,minx,maxx,M)format long;h = (maxx-min

8、x)/(n-1);for j=1:(n+2*M)        u0(j) = IniU(minx+(j-2*M-1)*h);end u1 = u0;for k=1:M    for i=2*k+1:n+2*M        u1(i) = u0(i)-dt*a*(u0(i)-u0(i-1)/h-a*dt*(1-a*dt/h)* .       &

9、#160;    (u0(i)-2*u0(i-1)+u0(i-2)/2/h;    end    u0 = u1;endu = u1(2*M+1):(2*M+n);format short;用Richtmyer多步格式解对流方程function u = peRich(a,dt,n,minx,maxx,M)format long;h = (maxx-minx)/(n-1);for j=1:(n+4*M)        u0(j) = In

10、iU(minx+(j-2*M-1)*h);end u1 = u0;for k=1:M    for i=2*k+1:n+4*M-2*k        tmpU1 = -dt*a*(u0(i+2)-u0(i)/h/4+(u0(i+2)+u0(i)/2;        tmpU2 = -dt*a*(u0(i)-u0(i-2)/h/4+(u0(i)+u0(i-2)/2;    

11、60;           u1(i) = -dt*a*(tmpU1-tmpU2)/h/2+u0(i);    end    u0 = u1;endu = u1(2*M+1):(2*M+n);format short;用拉克斯-温德洛夫多步格式解对流方程function u = peMLW(a,dt,n,minx,maxx,M)format long;h = (maxx-minx)/(n-1);for j=1:(n+2*M) 

12、       u0(j) = IniU(minx+(j-M-1)*h);end u1 = u0;for k=1:M    for i=k+1:n+2*M-k        tmpU1 = -dt*a*(u0(i+1)-u0(i)/h/2+(u0(i+1)+u0(i)/2;        tmpU2 = -dt*a*(u0(i)-u0(i-1)/h/2+(u0

13、(i)+u0(i-1)/2;                u1(i) = -dt*a*(tmpU1-tmpU2)/h+u0(i);    end    u0 = u1;endu = u1(M+1):(M+n);format short;用MacCormack多步格式解对流方程function u = peMC(a,dt,n,minx,maxx,M)format long;h = (ma

14、xx-minx)/(n-1);for j=1:(n+2*M)    u0(j) = IniU(minx+(j-M-1)*h);end u1 = u0;for k=1:M    for i=k+1:n+2*M-k        tmpU1 = -dt*a*(u0(i+1)-u0(i)/h+u0(i);        tmpU2 = -dt*a*(u0(i)-u0(i-1)/h+u0(i-1

15、);                u1(i) = -dt*a*(tmpU1-tmpU2)/h/2+(u0(i)+tmpU1)/2;    end    u0 = u1;endu = u1(M+1):(M+n);format short;用拉克斯-弗里德里希斯格式解二维对流方程的初值问题function u = pe2LF(a,b,dt,nx,minx,maxx,ny,miny,maxy

16、,M)%啦-佛format long;hx = (maxx-minx)/(nx-1);hy = (maxy-miny)/(ny-1);for i=1:nx+2*M    for j=1:(ny+2*M)        u0(i,j) = Ini2U(minx+(i-M-1)*hx,miny+(j-M-1)*hy);    endend u1 = u0;for k=1:M    for i=k+1:nx+2*M-k &

17、#160;      for j=k+1:ny+2*M-k            u1(i,j) = (u0(i+1,j)+u0(i-1,j)+u0(i,j+1)+u0(i,j-1)/4 .                 -a*dt*(u0(i+1,j)-u0(i-1,j)/2

18、/hx .                 -b*dt*(u0(i,j+1)-u0(i,j-1)/2/hy;        end    end    u0 = u1;endu = u1(M+1):(M+nx),(M+1):(M+ny);format short;    

19、;        用拉克斯-弗里德里希斯格式解二维对流方程的初值问题function u = pe2FL(a,b,dt,nx,minx,maxx,ny,miny,maxy,M)%近似分裂format long;hx = (maxx-minx)/(nx-1);hy = (maxy-miny)/(ny-1);for i=1:nx+4*M    for j=1:(ny+4*M)        u0(i,j) = Ini2U

20、(minx+(i-2*M-1)*hx,miny+(j-2*M-1)*hy);    endend u1 = u0;for k=1:M    for i=2*k+1:nx+4*M-2*k        for j=2*k-1:ny+4*M-2*k+2            tmpU(i,j) = u0(i,j) - a*dt*(u0(i+1,j)-u0(i-1,j)/2/hx + .                (a*