#复化辛普森法 def func1(a,b,n,f): x = np.linspace(a,b,n+1) sum1 = 0 h =(b-a)/n for i in range(补充代码3): 补充代码4 return sum1
时间: 2023-08-18 20:05:01 浏览: 75
补充代码3应该是range(n),表示循环n次。
补充代码4应该是:
```
if i == 0 or i == n:
sum1 += f(x[i])
elif i % 2 == 1:
sum1 += 4*f(x[i])
else:
sum1 += 2*f(x[i])
```
这里使用了复化辛普森公式来进行数值积分,对于区间[a,b],将其等分成n个小区间,每个小区间的长度为h=(b-a)/n,然后在每个小区间上分别使用三点公式计算积分,最终得到数值积分的近似值。
相关问题
import numpy as np import math from scipy import integrate def f(x): return math.sin(x)*math.sin(x) #复化梯形法 def func(a,b,n,f): x = np.linspace(a,b,n+1) sum1 = 0 h =(b-a)/n for i in range(补充代码1): 补充代码2 return sum1 #复化辛普森法 def func1(a,b,n,f): x = np.linspace(a,b,n+1) sum1 = 0 h =(b-a)/n for i in range(补充代码3): 补充代码4 return sum1 #复化科特斯法 def func2(a,b,n,f): x = np.linspace(a,b,n+1) sum1 = 0 h =(b-a)/n for i in range(补充代码5): 补充代码6 return sum1 answer = func(0,1,100,f) answer1 = func1(0,1,100,f) answer2 = func2(0,1,100,f) print(answer,answer1,answer2) #integrate积分作为精确值 value, error = integrate.quad(f,0, 1) print(value,error) print("error: ", abs(answer-value), abs(answer1-value), abs(answer2-value))
代码中缺少部分内容,需要进行补充。以下是三种数值积分方法的完整代码:
```python
import numpy as np
import math
from scipy import integrate
def f(x):
return math.sin(x)*math.sin(x)
# 复化梯形法
def func(a, b, n, f):
x = np.linspace(a, b, n+1)
sum1 = 0
h = (b-a)/n
for i in range(1, n):
sum1 += f(x[i])
return h*(0.5*f(a) + sum1 + 0.5*f(b))
# 复化辛普森法
def func1(a, b, n, f):
x = np.linspace(a, b, n+1)
sum1 = 0
h = (b-a)/n
for i in range(1, n):
if i%2 == 0:
sum1 += 2*f(x[i])
else:
sum1 += 4*f(x[i])
return h*(f(a) + sum1 + f(b))/3
# 复化科特斯法
def func2(a, b, n, f):
x = np.linspace(a, b, n+1)
sum1 = 0
h = (b-a)/n
for i in range(1, n):
if i%3 == 0:
sum1 += 2*f(x[i])
else:
sum1 += 3*f(x[i])
return h*(f(a) + sum1 + f(b))*3/8
answer = func(0,1,100,f)
answer1 = func1(0,1,100,f)
answer2 = func2(0,1,100,f)
print(answer,answer1,answer2)
# integrate积分作为精确值
value, error = integrate.quad(f, 0, 1)
print(value,error)
print("error: ", abs(answer-value), abs(answer1-value), abs(answer2-value))
```
其中,补充代码1,补充代码3,补充代码5 分别表示循环的次数,可设置为 `for i in range(1, n):`。补充代码2,补充代码4,补充代码6 分别表示不同积分方法中的积分公式,具体可参考课程中的讲解。
import numpy as np import math from scipy import integrate#复化辛普森法 def func1(a,b,n,f): x = np.linspace(a,b,n+1) sum1 = 0 h =(b-a)/n for i in range(补充代码3): 补充代码4 return sum1
补充代码3应该是 `n`,因为需要对区间 `[a,b]` 进行 `n` 段划分。
补充代码4应该是 `sum1 += f(x[i])`,因为需要把每个子区间的积分值加起来。
所以完整代码如下:
```python
import numpy as np
import math
from scipy import integrate
#复化辛普森法
def func1(a,b,n,f):
x = np.linspace(a,b,n+1)
sum1 = 0
h =(b-a)/n
for i in range(n):
sum1 += f(x[i]) + 4*f((x[i]+x[i+1])/2) + f(x[i+1])
return sum1*h/6
```
其中 `f` 是被积函数。
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