问题

以下是一个基本的 Python 脚本失败了：

from scipy import integrate
integrate.quadrature(lambda t: max(1,t), -2, 2)[0]

出现了以下错误信息：

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

在我看来，integrate.quadrature 命令似乎不喜欢 max 函数，但我不明白为什么。

from scipy import integrate
integrate.quadrature(lambda t: max(1,t), -2, 2)[0]

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

答案1

得分: 1

`scipy`没有将标量或1个元素的数组传递给您的函数，因此它需要进行向量化处理：

```python
from scipy import integrate
import numpy as np

integrate.quadrature(lambda t: np.maximum(1, t), -2, 2)[0]

您将收到如下警告：

AccuracyWarning: maxiter (50) exceeded. Latest difference = 6.366377e-04

然而，结果将接近预期值4.5：

4.499480255789206

这是一个参考图表：

t = np.linspace(-2, 2, 100)
plt.plot(t, np.maximum(1, t))

[![enter image description here][1]][1]

<details>
<summary>英文:</summary>

`scipy` is not passing a scalar or 1-element array to your function, so it needs to be vectorized:

from scipy import integrate
import numpy as np

integrate.quadrature(lambda t: np.maximum(1, t), -2, 2)[0]

You will get a warning like

    AccuracyWarning: maxiter (50) exceeded. Latest difference = 6.366377e-04

However, the result will be close to the expected value of 4.5:

    4.499480255789206

Here is a plot for reference:

t = np.linspace(-2, 2, 100)
plt.plot(t, np.maximum(1, t))

[![enter image description here][1]][1]


  [1]: https://i.stack.imgur.com/WiQvW.png

</details>