Employs the midpoint rule to integrate f between a and b Input arguments: f, function handle a,b, integration bounds, a<b Output arguments: Q, value of integral
0001 function [ Q ] = midpoint_rule( f,a,b ) 0002 % Employs the midpoint rule to integrate f between a and b 0003 % Input arguments: 0004 % f, function handle 0005 % a,b, integration bounds, a<b 0006 % Output arguments: 0007 % Q, value of integral 0008 0009 % first check user inputs 0010 if isa(f,'function_handle')==0; 0011 error('input must be a function handle'); 0012 elseif a>=b; 0013 error('invalid interval'); 0014 end 0015 0016 m=(a+b)/2; % calculate midpoint 0017 fm=feval(f,m); % evaluate f at the midpoint 0018 0019 Q=(b-a)*fm; % evaluate Q according to midpoint rule 0020 0021 end 0022