python matplotlib drawing

Import the matpltlib library

matplotlib is an excellent third-party library for python data visualization
. When using the matpltlib library to draw, first import it, load the pyplot inside, and name it plt, and then use the plot function to draw

import matplotlib.pyplot as plt #plt是引入模块的别名

Summary of pyplot basic icon functions

function	effect
plt.plot(x,y,format)	draw coordinates
plt.plot(data,notch,position)	Draw a boxplot
plt.bar(left,height,width,bottom)	draw a bar graph
plt.barh(width,bottom,left,height)	Draw a horizontal bar chart
plt.polar(theta,r)	Draw Polar Plot
plt.pie(data,explode)	draw pie chart
plt.hist(x,bins,normed)	draw histogram
plt.scatter(x,y)	Draw a scatterplot

There are many more hahaha, no longer pay attention to list

Plot function drawing syntax rules

Plot function parameters:plot([x],y,[format],**kwargs)

parameter	use
x	x-axis data, list or array
y	y-axis data, list or array
format	format string for control curve
**quargs	second group or more (x, y, string)

There are too many kinds of grammar, steal a few MOOC pictures and put them up~

line chart

from matplotlib import pyplot as plt

#生成数据
#横坐标数据从2017到2022，第三个参数可控制步长，可写可不写
x = range(2017, 2022)
#y对应纵坐标的值
y1 = [49, 48, 45, 52, 50]
y2 = [60, 62, 61, 65, 63]
#生成图形
plt.title("LMY and her mother's weight")
plt.xlabel('year')
plt.ylabel('kg')
plt.plot(x, y1, color='green', label='LMY')
plt.plot(x, y2, color='purple', label='mother')
plt.grid(alpha=0.5)
plt.legend(loc='upper right')
#显示图形
plt.show()

Scatterplot

from matplotlib import pyplot as plt
import numpy as np

# 生成数据
# 横坐标数据从2017到2022，第三个参数可控制步长，可写可不写
x = range(2017, 2022)
# y对应纵坐标的值
y1 = [49, 48, 45, 52, 50]
y2 = [60, 62, 61, 65, 63]
# 生成图形
plt.title("LMY and her mother's weight")
plt.xlabel('year')
plt.ylabel('kg')
# 点的大小
area = np.pi*4**2
plt.scatter(x, y1, s=area, c='yellow', alpha=1)
plt.scatter(x, y2, s=area, c='blue', alpha=1)
plt.legend()
plt.yticks(())
plt.show()

histogram

from matplotlib import pyplot as plt
import numpy as np

# 生成数据
# 横坐标数据从2017到2022，第三个参数可控制步长，可写可不写
x = [2017, 2018, 2019, 2020, 2021]
# y对应纵坐标的值
y1 = [49, 48, 45, 52, 50]
y2 = [60, 62, 61, 65, 63]
# 生成图形
plt.title("LMY and her mother's weight")
plt.ylabel('frequency')
plt.xlabel('kg')
# 点的大小
plt.hist(y1, bottom=None, color='purple')
plt.hist(y2, bottom=None, color='pink')
plt.show()

# n, bins, patches = plt.hist(arr, bins=50, normed=1, facecolor='green', alpha=0.75)
'''
arr:需要计算直方图的一维数组
bins:直方图的柱数，可选项，默认为10
normed:是否将得到的直方图向量归一化，默认为0
facecolor:直方图颜色
alpha:透明度
'''

bar chart

portrait

from matplotlib import pyplot as plt
import numpy as np

arr = np.arange(2017, 2022)
x = [49, 48, 45, 52, 50]  # x轴
y = [2017, 2018, 2019, 2020, 2021]
rect = plt.bar(arr, x, width=0.5)
plt.title('LMY')
plt.xlabel('weight')
plt.ylabel('year')
plt.legend()

plt.show()

horizontal

many lines

from matplotlib import pyplot as plt
import numpy as np

arr = np.arange(2017, 2022)
x1 = [49, 48, 45, 52, 50]  # x轴
x2 = [60, 62, 61, 65, 63]
y = [2017, 2018, 2019, 2020, 2021]
rects1 = plt.bar(arr, x1, 0.5, color='purple', label='LMY')
rects2 = plt.bar(arr, x2, 0.5, color='yellow', label='Mother', alpha=0.3)
plt.title("LMY and her mother's weight")
plt.xlabel('weight')
plt.ylabel('year')
plt.legend()

plt.show()

pie chart

from matplotlib import patches, pyplot as plt
import numpy as np

label_list = ['49', '48', '45', '52', '50']
size = [20, 20, 20, 20, 20]
# 各部分的颜色
color = ['red', 'pink', 'blue', 'green', 'purple']
explode = [0, 0, 0.15, 0, 0]

patches, l_text, p_text = plt.pie(size, explode=explode, colors=color, labels=label_list,
                                  labeldistance=1.2, autopct="%1.2f%%", shadow=False, startangle=90, pctdistance=0.6)
plt.axis('equal')
plt.title("LMY's weight")
plt.legend(loc='upper left')
plt.show()