func5p1.m

数值分析最常用的四十种算法

%func5p1.m各种方法求积分
%Integration,using N-L methom
I1=4*(atan(1)-atan(0))
%Trapz Rule
I2=1/2*(sub5p1(1)+sub5p1(0))
%Simpson Rule
I3=1/6*(sub5p1(1)+4*sub5p1(1/2)+sub5p1(0))
%Composite Trapezoidal Rule
x=linspace(0,1,100)
I4=0
for i=1:99
I4=I4+sub5p1(x(i))+sub5p1(x(i+1))
end
I4=I4/2/100
%I1=3.1416(precise vaule),I2=3,I3=3.1333,I4=3.1102
%三种数值方法中,Simpson公式最为接近真实值，且计算次数远少于复化梯形公式。