python作图函数2

写标记–annotate函数

import matplotlib.pyplot as plt
import numpy as np

x = np.arange(-10,11,1)

y = x*x

plt.plot(x,y)
plt.annotate('this is the bottom',xy=(0,1),xytext=(0,20),
             arrowprops=dict(facecolor='r',frac=0.2))

plt.show()

xy=(0,1)----箭头启示地点
xytext=(0,20)-----文字起始地点
arrowprops=dict(facecolor=‘r’,frac=0.2))—让其出现箭头

只有数字的标识–text（）

y = x*x
plt.plot(x,y)
plt.text(0,40,#--起始位置
		"fuction:y=x*x",#写的是字
         family='serif',#
         size=20,#字体大小
         color='b',#字体颜色
         style='italic',#字体样式，宋体什么的
         weight=1000#字体粗细
         )

plt.show()

TeX公式-写数学公式

$y=x+2$

公式写在美元符号之内

import matplotlib.pyplot as plt
import numpy as np

fig=plt.figure()
ax=fig.add_subplot(111)
ax.set_xlim([1, 7])
ax.set_ylim([1, 5])
ax.text(2, 4, r"$\alpha_i \beta_j \pi \lambda \omega$",size=20)  # 来个r，不转义字符
ax.text(4, 4, r"$ \sin(0)=\cos(\frac{pi}{2})$",size=20)  # 来个r，不转义字符
ax.text(2, 2, r"$ \lim_{x \rightarrow y} \frac{1}{x^3}$",size=20)
ax.text(4, 2, r"$ \sqrt[4]{x}=\sqrt[2]{y}$",size=20)


plt.show()

工具栏

N = 1000
x = np.random.rand(N)
y = np.random.rand(N)
colors = np.random.rand(N)
area = np.pi*(15*np.random.rand(N))

plt.scatter(x, y, s=area, c=colors, alpha=0.6)
plt.show()

填充颜色—fill(x,y,‘r’)

x = np.linspace(0,5*np.pi, 1000)
y1 = np.sin(x)
y2 = np.sin(2*x)
plt.plot(x, y1)
plt.plot(x, y2)
plt.fill(x,y1,'b',alpha=0.3)# 填充颜色fill
plt.fill(x,y2,'r',alpha=0.1)

plt.show()

填充

import matplotlib.patches as mpatches-----需要多一个方法

import matplotlib.pyplot as plt
import numpy as np
import matplotlib.patches as mpatches
ax = plt.subplot()
xy1 = np.array([0.2,0.2])
xy2 = np.array([0.2,0.8])
circle=mpatches.Circle(xy1,0.1)
ax.add_patch(circle)

rect = mpatches.Rectangle(xy2,0.2,0.1)
ax.add_patch(rect)
plt.axis('equal')

plt.grid()
plt.show()

生成一个极坐标

import matplotlib.pyplot as plt
import numpy as np

r = np.arange(1,6,1)#1-5的半径
#每个点的位置
theta = [0, np.pi/2, np.pi, 3*np.pi/2, 2*np.pi]
# projection='polar'  投影成极坐标
ax = plt.subplot(111,projection='polar')

ax.plot(theta,r,color='r',linewidth=3)
ax.grid(True)
plt.show()

4边型

import matplotlib.pyplot as plt
import numpy as np

r = np.empty(5)#1-5的半径
r.fill(5)
#每个点的位置
theta = [0, np.pi/2, np.pi, 3*np.pi/2, 2*np.pi]
# projection='polar'  投影成极坐标
ax = plt.subplot(111,projection='polar')

ax.plot(theta,r,color='r',linewidth=3)
ax.grid(True)
plt.show()