simpsonc.m

sareli<matlab科学计算>配套程序

function [Isic]=simpsonc(a,b,M,f,varargin)
%SIMPSONC Composite Simpson numerical integration.
%   ISIC = SIMPSONC(A,B,M,FUN) computes an approximation of the integral 
%   of the function FUN via the Simpson method (with M equispaced intervals).
%   FUN accepts real scalar input x and returns a real scalar
%   value. FUN can also be an inline object.
H=(b-a)/M;
x=linspace(a,b,M+1);
fpm=feval(f,x,varargin{:});
fpm(2:end-1) = 2*fpm(2:end-1);
Isic=H*sum(fpm)/6;
x=linspace(a+H/2,b-H/2,M);
fpm=feval(f,x,varargin{:});
Isic = Isic+2*H*sum(fpm)/3; 
return