Fortran程序： parameter(pi=3.1415926535) real kn real,allocatable :: vs(:,:),vf(:,:) a=1234.; n0=7; ny=100; u0=1. b=a/float(n0); ds=b/float(ny); nx=n0*ny errs=1.e-6; errf=1.e-6 allocate(vs(0:nx,0:ny),vf(0:nx,0:ny)) vs=0.; vs(1:nx-1,ny)=u0; vf=vs !---------------------------------------------------------- open(1,file='nvs.dat') do i=1,nx-1; x=float(i)*ds do j=1,ny-1; y=float(j)*ds err=1.; nc=0 do while(err.gt.errs) fnc=2.*float(nc)+1.; kn=pi*fnc/a t=sin(kn*x)*(1.-exp(-2.*kn*y))/(fnc*(exp(kn*(b-y))-exp(-kn*(b+y)))) err=abs(t) vs(i,j)=vs(i,j)+t nc=nc+1 enddo write(1,*) x,y,nc vs(i,j)=vs(i,j)*(4.*u0/pi) enddo enddo close(1) open(1,file='vs.dat') do i=0,nx; x=float(i)*ds do j=0,ny; y=float(j)*ds write(1,*) x,y,vs(i,j) enddo enddo close(1) !---------------------------------------------------------- err=1. do while(err.gt.errf) do i=1,nx-1; x=float(i)*ds do j=1,ny-1; y=float(j)*ds t=0.25*(vf(i+1,j)+vf(i-1,j)+vf(i,j+1)+vf(i,j-1)) if(i.ne.1.or.j.ne.1) then err0=abs(t-vf(i,j)); err=amax1(err,err0) else err=abs(t-vf(i,j)) endif vf(i,j)=t enddo enddo enddo open(1,file='vf.dat') do i=0,nx; x=float(i)*ds do j=0,ny; y=float(j)*ds write(1,*) x,y,vf(i,j) enddo enddo close(1) !--------------------------- a0=0.5*a; b0=0.8*b open(1,file='a0.dat'); open(2,file='b0.dat') i=nint(a0/ds); do j=0,ny; write(1,*) float(j)*ds,vs(i,j),vf(i,j); enddo; close(1) j=nint(b0/ds); do i=0,nx; write(2,*) float(i)*ds,vs(i,j),vf(i,j); enddo; close(2) !--------------------------- write(*,*) err,i0,j0 deallocate(vs,vf) stop end