how to plot trapezoidal rule
显示 更早的评论
Hello i coded trapezoidal rule but how can i plot it ?here is my code
t = 0:0.2:2*pi;
f = @(x) 3*cos(t*1000);
a = 0;
b = 2*pi;
n = length(t)-1;
h =(b-a)/n;
for i=1:1:n-1
sum = sum + f(a+i*h);
end
result = h/2*(f(a)+f(b)+2*sum);
fprintf('%f',result);
1 个评论
Torsten
2021-12-29
Your variable "result" is just a single number, namely the approximated area under the function f in the interval [0:2*pi].
So what do you want to plot ? How the area develops from 0 to 2*pi ?
采纳的回答
Pratyush Roy
2022-1-7
Hi,
One can use the polyshape function to create polygons (trapezium in this case) and use hold on and off to show them in a single figure. The following code might be helpful to understand how this works:
h = 0.2;
t = 0:h:2*pi;
f = @(x) 3*cos(x*1000);
a = 0;
b = 2*pi;
n = length(t);
sum1 = 0;
plot(t,f(t));
hold on;
for i=0:1:n-1
sum1 = sum1 + f(a+i*h);
if (i>=0)
plot(polyshape([a+i*h,a+i*h,a+(i+1)*h,a+(i+1)*h],[0,f(a+i*h),f(a+(i+1)*h),0]),'FaceColor','red');
hold on;
end
end
hold off;
result = h/2*(f(a)+f(b)+2*sum1);
Hope this helps!
更多回答（0 个）
类别
在 帮助中心 和 File Exchange 中查找有关 2-D and 3-D Plots 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
