我创建了以下代码，该代码可以执行二分法。
我正在尝试使用它来找到函数f（x）= x ^ 7-6x ^ 6-28x ^ 5 + 232x ^ 4-336x ^ 3-544x ^ 2 + 1728x-1152的根间隔[1，3.1]。
已提示我x_0 = 2是此间隔上此函数的根。我得到的是没有根，我希望有人可以帮助我解决这个问题！
下面是我的代码：
import math
import numpy as np
def root(x):
return (x**7-6*x**6-28*x**5+232*x**4-336*x**3-544*x**2+1728*x-1152)
def bisection_method(f, a, b, tol):
if f(a)*f(b) > 0:
#end function, no root.
print("No root found.")
else:
iter = 0
while (b - a)/2.0 > tol:
midpoint = (a + b)/2.0
if f(a)*f(midpoint) < 0: # Increasing but below 0 case
b = midpoint
else:
a = midpoint
iter += 1
return(midpoint, iter)
answer, iterations = bisection_method(root, 1, 3.1, 10**(-14))
print("Answer:", answer, "\nfound in", iterations, "iterations")
这是我得到的输出：
No root found.
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-6-ecdc56120415> in <module>()
21 return(midpoint, iter)
22
---> 23 answer, iterations = bisection_method(root, 1, 3.1, 10**(-14))
24 print("Answer:", answer, "\nfound in", iterations, "iterations")
TypeError: 'NoneType' object is not iterable