编制数值积分的复合梯形算法、复合辛普森算法、复合科茨算法的matalab程序
时间: 2024-11-13 16:14:11 浏览: 46
cPP.rar_复合梯形积分_高斯积分c
在MATLAB中,编写数值积分的复合梯形、复合辛普森算法以及复合柯特斯算法通常涉及循环结构和累加求和。以下是简化的示例代码:
**1. 复合梯形法则 (Composite Trapezoidal Rule):**
```matlab
function integral = composite_trapezoid(f, a, b, n)
h = (b - a) / n; % 步长
sum_area = (f(a) + f(b)) * h / 2; % 首尾梯形面积
for i = 1:n-1
x = a + (i + 0.5) * h;
sum_area += f(x); % 累加中间梯形面积
end
integral = sum_area;
end
```
**2. 复合辛普森法则 (Composite Simpson's Rule):**
```matlab
function integral = composite_simpson(f, a, b, n)
if mod(n, 2) == 1 % 如果n是奇数,添加一个点到中间
n = n + 1;
h = (b - a) / n;
x_mid = a + (n / 2) * h;
f_mid = f(x_mid);
else
h = (b - a) / n;
end
sum_area = f(a) + f(b) + 4 * sum([f(a+h) f(2*a+h) f(3*a+h) ... f((n-2)*h+a) f((n-1)*h+a)]) * h / 6;
if mod(n, 2) == 1 % 如果n是奇数,修正中间点
sum_area -= f_mid * h / 3;
end
integral = sum_area;
end
```
**3. 复合柯特斯法则 (Composite Clenshaw-Curtis Quadrature):**
```matlab
function integral = composite_clenshaw_curtis(f, a, b, n)
% Clenshaw-Curtis节点
nodes = linspace(a, b, n + 1);
% 计算函数值并计算积分
weights = zeros(n, 1);
for j = 1:n
weights(j) = (-1)^(j-1) / factorial(j);
end
integral = weights' * f(nodes);
end
```
在使用这些函数之前,需要确保`f`是你想要积分的函数,并传入正确的区间`[a, b]`和阶数`n`。
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