将函数从sympy转换为numpy（属性错误）

import numpy as np
import sympy as sym
from numpy import sin
from sympy import symbols, diff

func = lambda x: sin(x)
x    = symbols('x')
print diff(func(x),x)

This works if I replace my function with a polynomial, or if I place the trig function directly into the diff operator. But in this format I get AttributeError: sin.

如果我用多项式替换我的函数，或者我将trig函数直接放入diff运算符，这是有效的。但是在这种格式中，我得到了AttributeError：sin。

Basically I think python can't recognize func as just being a trig function which it knows how to symbolically integrate. I could just have sympy import sin and then things would work, but then I'm stuck with func referencing sin in the sympy namespace and there are future things I want to do with func which require that it be defined using sin in the numpy namespace.

基本上我认为python不能将func识别为只知道如何进行符号集成的trig函数。我可能只有同情导入罪，然后事情就会起作用，但是后来我坚持使用func在sympy命名空间中引用sin，并且我想用func进行未来的事情，这需要在numpy命名空间中使用sin来定义它。

2 个解决方案

#1

You should build your expression up symbolically using SymPy functions, and then use lambdify to convert them into things that can be evaluated with NumPy.

您应该使用SymPy函数以符号方式构建表达式，然后使用lambdify将它们转换为可以使用NumPy计算的内容。

#2

This simply isn't how you use sympy. You can't use normal functions in conjunction with numpy--you need to build symbolic expressions using the stuff it provides.

这根本不是你如何使用sympy。你不能将普通函数与numpy结合使用 - 你需要使用它提供的东西来构建符号表达式。

To write code to get the derivative of sin(x), you would do

要编写代码来获得sin（x）的导数，你会这样做

import sympy as sym
from sympy import sin, symbols, diff

x = symbols('x')
print diff(sin(x), x)

If you have some other particular case you're having trouble with, you'll have to show it. You can't mix sympy with non-sympy stuff in this way, so there isn't some general feedback that can be provided.

如果您遇到其他特殊情况，则需要进行展示。你不能以这种方式将同情与非同情的东西混在一起，所以没有一些可以提供的一般性反馈。

#1