使用Integrate.quad进行积分时出现无效浮动错误

Question

我有一个清单：

q1 = [0,1.9488e-06,1.5473e-05,5.1829e-05,0.00012192,0.00023633,0.00040526,0.00063862,0.00094596,0.0013365,0.0018192,0.0024025,0.0030949,0.0039041,0.0048379,0.0059036]

我正在尝试整合。 我做了以下事情：

def f(x):
    if (np.abs(x)<1e-10):
        res = x
    else:
        res = q2[:10]
    return res
x = np.arange(0,10,0.001)
def F(x):
    res = np.zeros_like(x)
    for i,val in enumerate (x):
        y,err = integrate.quad(f,0,val)
        res[i] = y
    return res     
plt.plot(F(x))

当我尝试运行此代码时，出现此错误：

Traceback (most recent call last):

File "<ipython-input-88-ca3005760f4b>", line 19, in <module>
  plt.plot(F(x))

File "<ipython-input-88-ca3005760f4b>", line 14, in F
  y,err = integrate.quad(f,0,val)

File "C:\Anaconda2\lib\site-packages\scipy\integrate\quadpack.py", line 311, 
in quad points)

File "C:\Anaconda2\lib\site-packages\scipy\integrate\quadpack.py", line 376, 
in _quad
  return _quadpack._qagse(func,a,b,args,full_output,epsabs,epsrel,limit)

error: Supplied function does not return a valid float.

任何人都可以帮助我理解为什么我会收到此错误吗？

Answer 1

您遇到此错误是因为

f

中的这两行：

    else:
        res = q2[:10]

在这里，您将从函数返回列表的一部分。

quad

不喜欢这样；根据其文档，它需要一个返回双精度值（即Python浮点数）的函数，而不是列表。

虽然您的问题中没有给出您的预期输出，但将该行更改为

        res = q2[0]

或

q2

中的任何其他任意索引可纠正错误。