5_4.asv

matlab 相关的数值积分 例如高斯积分 龙贝格积分等等 可参考。

%%%%%%%%  Double Integration by the Simpson's Rule  %%%%%%%%
nx=input('Number of intervals in x_direction:');
ny=input('Number of intervals in y_direction:');
a=input('Lower limit of x,a?');
b=input('Lower limit of x,b?');
hx=(b-a)/nx;
x=[a:hx:b];
cy=c(x);
dy=d(x);
hy=(d(x)-c(x))/ny;
Result=0;
temp=0;

for i=1:nx
    for j=1:ny
        y=[c(j):hy:d(j)]
        y=f(x(i),y)
         temp=hy(j)/2*(2*sum(y)-f(x(i),c(j))-f(x(i),d(j)));
    end
    if i~=1&i~=nx temp=temp*2;end
    Result=Result+temp;
end
Result=hx/2*Result
h=(b-a)/n;
x=[a:h:b];
y=f(x);
Result=h/2*