fct2dlaplace.m

本代码为基于matlab的求解偏微分方程的利用径向基函数的无网格方法的源码

function z=fct2DLaplace(x,y) % Laplacian of fct2D, not completely tested
global func3d
[nx,ny]=size(x);
switch func3d
case 1
 z=6-x.^2-y.^2;
 if z>=0
     z=4*ones(nx,1);
 else
     z=-4*ones(nx,1);
 end 
case 2  % peaks(.,.), we have to discretize
    dx=max(abs(x).*1.0e-7,1.0e-7);
    hxp=x+dx;
    hxm=x-dx;
    dy=max(abs(y).*1.0e-7,1.0e-7);
    hyp=y+dy;
    hym=y-dy;
    z=(peaks(hxp,y)-2*peaks(x,y)+peaks(hxm,y))./(dx.*dx)+(peaks(x,hyp)-2*peaks(x,y)+peaks(x,hym))./(dy.*dy);
case 3    %2
    z=4*ones(nx,1); 
case 4
    z=4*exp(-x.^2-y.^2).*(-1+x.^2+y.^2); 
case 5
 z=4*exp(-x.^2-5*y.^2).*(-3+x.^2+25*y.^2);
end