学习笔记3 matplotlib

一、认识matplotlib

matplotlib：能将数据进行可视化，更直观的呈现
使数据更加客观、更具说服力

1.Figure

在任何绘图之前，我们需要一个Figure对象，可以理解成我们需要一张画板才能开始绘图。

from matplotlib import pyplot as plt
plt.figure(figsize=(20,8),dpi=80)  #调节图形大小

2.Axes

绘制轴，可以理解成为真正可以作画的纸。

fig.add_subplot(111)

是添加Axes的，参数的解释的在画板的第1行第1列的第一个位置生成一个Axes对象来准备作画。

fig, axes = plt.subplots(nrows=2, ncols=2)

可一次性生成所有Axes。

3.绘制基本图形

plot函数：绘制基本曲线；可以接收任意数量的参数。

from matplotlib import pyplot as plt
x=range(2,26,2)
y=[15,13,14.5,17,20,25,26,26,24,22,18,15]
plt.plot(x,y)
plt.show()

二、使用流程

1. 明确问题
2. 选择图形的呈现方式
3. 准备数据
4. 绘图和图形完善

三、图形样式

1. 折线图
   matplotlib.plot(x,y)
2. 散点图
   matplotlib.scatter(x,y)
3. 柱状图
   matplotlib.bar(x,y)
   matplotlib.barh(x,y)
4. 直方图
   matplotlib.hist(data,bins,normed)

1.折线图

matplotlib.plot(x,y)

import matplotlib.pyplot as plt
x=range(2,26,2)
y=[15,13,14.5,17,20,25,26,26,24,22,18,15]
plt.figure(figsize=(20,8),dpi=80)  #调节图形大小
plt.plot(x,y)
_xtick_labels=[i/2 for i in range(4,49)]
#根据所需改变x轴和y轴
plt.xticks(_xtick_labels[::2])   
plt.yticks(range(min(y),max(y)+1))
#plt.savefig("./sig_size.png")    保存
plt.show()

import random
import matplotlib.pyplot as plt
#import matplotlib
#font={'family':'MicroSoft YaHei','weight':'bold','size':'larger'}
#matplotlib.rc("font",**font)

#输出中文
from matplotlib import font_manager
my_font=font_manager.FontProperties(fname=r"c:\windows\fonts\simsun.ttc",size=14)

x=range(120)
y=[random.randint(20,35) for i in range(120)]

plt.figure(figsize=(20,8),dpi=80)

plt.plot(x,y)

_x=list(x)[::3]
_xtick_labels=["10点{}分".format(i) for i in range(60)]
_xtick_labels+=["11点{}分".format(i) for i in range(60)]

plt.xticks(_x[::3],_xtick_labels[::3],rotation=45,fontproperties=my_font)

#设置坐标轴标签
plt.xlabel("时间",fontproperties=my_font)
plt.ylabel("温度 单位(℃)",fontproperties=my_font)

#设置标题
plt.title("10点到12点每分钟的气温变化情况",fontproperties=my_font)

plt.show()

from matplotlib import pyplot as plt
from matplotlib import font_manager
my_font=font_manager.FontProperties(fname=r"c:\windows\fonts\simsun.ttc",size=14)

x=range(11,31)
y_1=[1,0,1,1,2,4,3,2,3,4,4,5,6,5,4,3,3,1,1,1]
y_2=[1,0,3,1,2,2,3,3,2,1,2,1,1,1,1,1,1,1,1,1]

plt.figure(figsize=(20,8),dpi=80)

#设置图例、标签
plt.plot(x,y_1,label="自己",color="cyan",linestyle=':')
plt.plot(x,y_2,label="同桌",color="purple",linestyle='--')

_x=list(x)
_xtick_labels=["{}岁".format(i) for i in range(11,31)]
plt.xticks(_x,_xtick_labels,rotation=45,fontproperties=my_font)
plt.yticks(range(0,9))

#设置网格线
plt.grid(alpha=0.4)

#设置图例（位置）
plt.legend(prop=my_font,loc="upper left")

plt.xlabel("岁数",fontproperties=my_font)
plt.ylabel("个数",fontproperties=my_font)

plt.show()

2.散点图

matplotlib.scatter(x,y)

from matplotlib import pyplot as plt
from matplotlib import font_manager
y_3=[11,17,16,11,12,11,12,6,6,7,8,9,12,15,14,17,18,21,16,17,20,14,15,15,15,19,21,22,22,22,23]
y_10=[26,26,28,19,21,17,16,19,18,20,20,19,22,23,17,20,21,20,22,15,11,15,5,13,17,10,11,13,12,13,6]
x=range(1,32)
plt.scatter(x,y_3)
plt.show()

from matplotlib import pyplot as plt
from matplotlib import font_manager

my_font=font_manager.FontProperties(fname=r"c:\windows\fonts\simsun.ttc",size=14)
y_3=[11,17,16,11,12,11,12,6,6,7,8,9,12,15,14,17,18,21,16,17,20,14,15,15,15,19,21,22,22,22,23]
y_10=[26,26,28,19,21,17,16,19,18,20,20,19,22,23,17,20,21,20,22,15,11,15,5,13,17,10,11,13,12,13,6]

x_3=range(1,32)
x_10=range(51,82)

plt.figure(figsize=(20,8),dpi=80)

plt.scatter(x_3,y_3,label="3月份")
plt.scatter(x_10,y_10,label="10月份")

_x=list(x_3)+list(x_10)
_xtick_labels=["3月{}日".format(i) for i in x_3]
_xtick_labels+=["10月{}日".format(i-50) for i in x_10]
plt.xticks(_x[::3],_xtick_labels[::3],fontproperties=my_font,rotation=45)

plt.legend(loc="upper left",prop=my_font)

plt.xlabel("时间",fontproperties=my_font)
plt.ylabel("温度",fontproperties=my_font)
plt.title("标题",fontproperties=my_font)

plt.show()

3.柱状图

matplotlib.bar(x,y) matplotlib.barh(x,y)

from matplotlib import pyplot as plt
from matplotlib import font_manager
my_font=font_manager.FontProperties(fname=r"c:\windows\fonts\simsun.ttc",size=14)

x=["战狼2","速度与激情8","功夫瑜伽","西游伏妖篇","变形金刚5:最后的骑士","摔跤吧！爸爸","加勒比海盗5:死无对证","金刚：骷髅岛","极限特工：终极回归","生化危机6：终章","乘风破浪","神偷奶爸3","智取威虎山","大脑天竺","金刚狼3：殊死一战","蜘蛛侠：英雄归来","悟空传","银河护卫队2","情圣","新木乃伊"]
y=[56.01,26.94,17.53,16.49,15.45,12.96,11.8,11.61,11.28,11.12,10.49,10.3,8.75,7.55,7.32,6.99,6.88,8.86,6.58,6.23]

plt.figure(figsize=(20,8),dpi=80)

plt.barh(range(len(x)),y,height=0.3,color="orange")

plt.yticks(range(len(x)),x,fontproperties=my_font)

plt.grid(alpha=0.3)

plt.show()

from matplotlib import pyplot as plt
from matplotlib import font_manager
my_font=font_manager.FontProperties(fname=r"c:\windows\fonts\simsun.ttc")

a=["猩球觉醒3：终极之战","敦刻尔克","蜘蛛侠：英雄归来","战狼2"]
b_16=[15746,312,4497,319]
b_15=[12357,156,2045,168]
b_14=[2358,399,2358,362]

bar_width=0.2

x_14=list(range(len(a)))
x_15=[i+bar_width for i in x_14]
x_16=[i+bar_width+0.2 for i in x_14]

plt.figure(figsize=(20,8),dpi=80)

plt.bar(x_14,b_14,width=bar_width,label="9月14日")
plt.bar(x_15,b_15,width=bar_width,label="9月15日")
plt.bar(x_16,b_16,width=bar_width,label="9月16日")

plt.legend(prop=my_font)

plt.xticks(x_15,a,fontproperties=my_font)


plt.show()

4.直方图

matplotlib.hist(data,bins,normed)

from matplotlib import pyplot as plt
from matplotlib import font_manager

a=[131,98,125,131,121,79,139,94,143,124,152,120,83,74,92,102]

d=3
num_bins=(max(a)-min(a))//d

plt.figure(figsize=(20,8),dpi=80)

plt.hist(a,num_bins,normed=True)

plt.xticks(range(min(a),max(a)+d,d))

plt.grid()

plt.show()

from matplotlib import pyplot as plt
from matplotlib import font_manager

interval=[0,5,10,15,20,25,30,35,40,45,60,90]
width=[5,5,5,5,5,5,5,5,5,15,30,60]
quantity=[835,2737,3723,3926,3596,1438,3273,642,824,613,215,47]

plt.figure(figsize=(20,8),dpi=80)

plt.bar(range(len(quantity)),quantity,width=1)

_x=[i-0.5 for i in range(13)]
_xtick_labels=interval+[150]
plt.xticks(_x,_xtick_labels)

plt.grid(alpha=0.4)

plt.show()