小编Åth*_*enå的帖子

我正在尝试创建一个函数来绘制我告诉它的任何公式.

import numpy as np  
import matplotlib.pyplot as plt  
def graph(formula, x_range):  
    x = np.array(x_range)  
    y = formula  
    plt.plot(x, y)  
    plt.show()  

当我尝试调用它时会发生以下错误,我相信它会在它到达之前尝试进行乘法运算y = formula.

graph(x**3+2*x-4, range(-10, 11))

Traceback (most recent call last):  
  File "<pyshell#23>", line 1, in <module>  
    graph(x**3+2*x-4, range(-10, 11))  
NameError: name 'x' is not defined