NIT工具箱 MATLAB
function int = quad2dggen(fun,xlow,xhigh,ylow,yhigh,tol) %usage: int = quad2dggen('Fun','funxlow','funxhigh',ylow,yhigh) %or % int = quad2dggen('Fun','funxlow','funxhigh',ylow,yhigh,tol) % %This function is similar to QUAD or QUAD8 for 2-dimensional integration %over a general 2-dimensional region, but it uses a Gaussian quadrature %integration scheme. %The integral is like: % yhigh funxhigh(y) % int = Int Int Fun(x,y) dx dy % ylow funxlow(y) % % int -- value of the integral % Fun -- Fun(x,y) (function to be integrated) % funxlow -- funxlow(y) % funxhigh-- funxhigh(y) % ylow -- lower y limit of integration % yhigh -- upper y limit of integration % tol -- tolerance parameter (optional) %Note that if there are discontinuities the region of integration %should be broken up into separate pieces. And if there are singularities, %a more appropriate integration quadrature should be used %(such as the Gauss-Chebyshev for a specific type of singularity). %This routine could be optimized.
