m5_1.m

来自「数值微分和数值积分:Newton-Cotes公式、复化公式和区间逐次半分法、外推」· M 代码 · 共 31 行

%%%%%%%%%%%%%%%%  Trapezoidal or Simpson  %%%%%%%%%%%%%%%%%%%%%%%%%%%
fprintf('\n Rules of Trapezoidal/Simpson\n');
fprintf('The function to be integrated is hard--coded infunction()\n');
z=input('Type 0 for Trapezoidal,or 1 for Simpson :');
while (z~=0 | z~=1)
    fprintf('\n\n Warn:Please enter 0 or 1!!\n');
    z=input('Type 0 for Trapezoidal,or 1 for Simpson :');
    if z==0|z==1 break;end
end
n=input('Numerical of interval?');
a=input('Lower limit of integration?');
b=input('upper limit of integration?');
h=(b-a)/n;
if z==0 
    x=[a:h:b];
    y=f(x);
    Result=h/2*(2*sum(y)-f(a)-f(b));
    fprintf('Result=%12.5f.\n',Result);
end
if z==1
    x=[a:h:b];
    for i=1:n
        xx(i)=x(i)+h/2;
    end
    yy=f(xx);
    y=f(x);
    Result=h/6*(4*sum(yy)+2*sum(y)-f(a)-f(b));
    fprintf('Result=%12.5f.\n',Result);
end