引入相关库

做这件事情，总是引入这两个库，所以复制即可！

In [2]:
import numpy as np
import matplotlib.pyplot as plt

绘制 $y=x$

In [4]:
x = np.linspace(1, 10, 1000)
y= x

plt.plot(x,y,'r',linewidth=2)
Out[4]:
[<matplotlib.lines.Line2D at 0x8991a20>]

绘制 $y=sin(x)$

In [5]:
x = np.linspace(1, 10, 1000)
y = np.sin(x)

plt.plot(x,y,'r',linewidth=2)
Out[5]:
[<matplotlib.lines.Line2D at 0x59f46d8>]

绘制一个圆

绕圆点，圆一个半径 r，角度 a 旋转 360度，弧度即 2π.

$x = r * cos(a)$

$y = r * sin(a)$

In [7]:
a = np.linspace(0, 2 * np.pi)
r = 100
x = r * np.cos(a)
y = r * np.sin(a)

plt.plot(x,y,'r',linewidth=2)
Out[7]:
[<matplotlib.lines.Line2D at 0x8991c18>]

来个复杂一点的（心形）

$r = 3 * (1 + cos(a))$

In [17]:
plt.axis([-1,9,-4,4])

a = np.linspace(0, 2 * np.pi, 1000)
r = 3 * (1 + np.cos(a))
x = r * np.cos(a)
y = r * np.sin(a)

plt.plot(x,y,'r',linewidth=2)
Out[17]:
[<matplotlib.lines.Line2D at 0x725dc18>]
In [ ]: