数据分析——matplotlib

基础

 # coding=utf-8
 import matplotlib.pyplot as pt
 import numpy as np
 from matplotlib import font_manager  # 字体管理

 # pt.figure(num='ljb',facecolor='y',figsize=(8,6))  #num画框名，facecolor画框颜色，figsize画框大小(宽，高)
 # pt.subplot(1,2,1)     #子画框，1行1列1号位置
 # X = np.linspace(-np.pi,np.pi,100)
 # Y = np.sin(X)
 # B = np.cos(X)
 # pt.plot(X,Y,c='b',lw=4,ls='--')   #c图形颜色，lw图形粗细，ls图形样式
 # pt.subplot(1,2,2)
 # pt.plot(X,B,c='g',lw=4,ls='--')
 # pt.savefig('./sinx.png')      #保存图形

 # pt.figure(num='haha',facecolor='g')
 # X = np.linspace(0,np.pi,100)
 # Y = np.cos(X)/np.sin(X)
 # Y = np.sin(X)/np.cos(X)
 # pt.plot(X,Y,'b+')

 # 行，列，位置
 # 画哪个就把哪个作为主体
 # pt.figure(facecolor='r')
 # X = np.linspace(-100, 100, 20)
 # Y = X ** 2
 # pt.xlabel(u'X数值')     #X轴名字
 # pt.ylabel(u'Y数值')     #Y轴名字
 # pt.subplot(3,1,1,facecolor='y')   #子图形颜色
 # pt.plot(X,Y,'bo')     #b蓝色blue ，形状：o圆点
 #
 # A = np.linspace(-np.pi,np.pi,10)
 # B = np.sin(A)
 # C = np.cos(A)
 # pt.subplot(3,3,4)
 # pt.plot(A,B,'g+')     #g绿色green，形状：+
 # pt.subplot(3,3,5)
 # pt.plot(A,C,'r*')     #r红色red，形状：*
 #
 # M = np.linspace(2, 10, 20)
 # N = np.log(M)
 # pt.subplot(3,3,6,facecolor='g')
 # pt.plot(M,N,'md')     #m紫色，形状d：钻石
 #
 # a = np.linspace(-100, 100, 20)
 # b = a ** 2
 # pt.subplot(3,2,5,facecolor='m')
 # pt.plot(a,b,'bo')
 # x = np.linspace(-100, 100, 20)
 # y = x ** 2
 # pt.subplot(3,2,6,facecolor='y')
 # pt.plot(x,y,'b>')
 # pt.show()
 # subplot(3,2,6)可以简写为subplot(326)

 pt.figure()
 # pt.rcParams['font.sans-serif'] = ['字体名']
 myfont = font_manager.FontProperties(fname=u'C:\Windows\Fonts\时尚中黑简体.ttf')
 X = np.linspace(-np.pi, np.pi, 50)
 Y = X ** 2
 Y1 = X ** 3
 Y2 = np.sin(X)
 # 设置xy轴上下限
 pt.xlim(-np.pi, np.pi)
 pt.ylim(-1, 1)
 # 设置x轴每个显示刻度
 pt.xticks([-np.pi, -np.pi / 2, 0, np.pi / 2, np.pi])
 # 设置某点坐标的文字:x坐标，y坐标以数据刻度为基准，显示的内容，字体配置
 pt.text(0.0, 0.5, 'ljb', fontdict={'size': '', 'color': 'm'})
 # 添加标注：xy:标注箭头想要指示的点，xytext：描述信息所在的坐标，arrowprops：设置箭头样式，shrink：箭头长度
 pt.annotate('note!', xy=(np.pi / 2, 1), xytext=(np.pi / 2, 0.25), fontsize=16,
             arrowprops=dict(facecolor='y', shrink=0.01))

 pt.xlabel(u'X数值', fontproperties=myfont, fontsize=12)  # X轴名字及字体设置
 pt.ylabel(u'Y数值', fontproperties=myfont, fontsize=12)  # Y轴名字及字体设置
 pt.title(u'函数图像', fontproperties=myfont, fontsize=16)  # 图形标题及字体设置
 # pt.plot(X,Y,label=u'X2函数')
 # pt.plot(X,Y1,label=u'X3函数')
 pt.plot(X, Y2, 'bo', label=u'sinx函数')  # label设置图例
 pt.legend(prop=myfont)  # 显示图例并设置字体
 pt.show()

柱状图

 # coding=utf-8
 import numpy as np
 import matplotlib.pyplot as pt

 # 柱状图--------------------------------------
 k = 10
 x = np.arange(k)    #生成序列数组
 y = np.random.rand(k)   #生成对应的随机数
 for t in x:     #text设置某点坐标的文字，ha，va设置文字位置，
     pt.text(t,y[t]+0.01,'%.2f' % y[t],ha='center',va='bottom',fontdict={'size':'','color':'r'})
 pt.annotate('%.2f' % y[4],xy=(4,y[4]+0.05),xytext=(4.3,y[4]+0.15),fontsize=16,arrowprops=dict(facecolor='y',arrowstyle='fancy'),bbox = dict(boxstyle="sawtooth",fc="0.8"))
 pt.bar(x,y)
 # pt.barh(x,y)      #横向柱状图
 pt.show()

 # 子图配置-----------------------------------------
 # pt.figure(figsize=(10, 6))
 # X = np.linspace(-np.pi, np.pi, 30)
 # Y_sin = np.sin(X)
 # Y_cos = np.cos(X)
 #
 # # 获取子图的配置
 # ax_sin = pt.subplot(121)      #需要把子图存起来
 # ax_sin.set_title('Sin(X)')    #单独设置某个子图标题
 # ax_sin.set_xlabel('X')        #单独设置某个子图x轴名字
 # ax_sin.set_ylabel('Y')        #单独设置某个子图y轴名字
 # pt.plot(Y_sin, 'bo')
 #
 # ax_cos = pt.subplot(122)
 # ax_cos.set_title('Cos(X)')
 # ax_cos.set_xlabel('X')
 # ax_cos.set_ylabel('Y')
 # pt.plot(Y_cos, 'r-')
 #
 # pt.show()

 # 分类柱状图-----------------------------------------------
 # from matplotlib import font_manager
 #
 # myfont = font_manager.FontProperties(fname=u'C:\Windows\Fonts\时尚中黑简体.ttf')
 #
 # b_16 = [15746, 312, 4497, 319]
 # b_15 = [12357, 156, 2045, 168]
 # b_14 = [2358, 399, 2358, 362]
 # a = [u'猩球崛起3', u'敦刻尔克', u'蜘蛛侠', u'战狼2']
 #
 # bar_width = 0.2 #设置一个条状图的宽度
 #
 # x_14 = list(range(len(a)))
 # x_15 = [i + bar_width for i in x_14]
 # x_16 = [i + bar_width * 2 for i in x_14]
 #
 # # 设置图形大小，分辨率
 # pt.figure(figsize=(12, 6), dpi=80)
 #
 # ax = pt.subplot(211)
 #
 # ax.set_title('Counter')
 # ax.set_xlabel('X')
 #参数1：位置列表，参数2：数据列表，参数3：柱宽，参数4：图例
 # pt.bar(range(len(a)), b_14, width=bar_width, label=u'9月14日')
 # pt.bar(x_15, b_15, width=bar_width, label=u'9月15日')
 # pt.bar(x_16, b_16, width=bar_width, label=u'9月16日')
 #
 # # 设置图例
 # pt.legend(prop=myfont)
 #
 # # 设置x轴的刻度
 # pt.xticks(x_15, a, fontproperties=myfont)
 # pt.show()

小案例

学生成绩

导入类库

 from matplotlib import font_manager
 import numpy as np
 import matplotlib.pyplot as pt

数据准备

 score_array = np.genfromtxt('score.csv', delimiter=',', dtype=int)
 courses = [u'数学', u'语文', u'化学', u'地理', u'音乐', u'体育']
 students = [u'小数', u'小语', u'小化', u'小地', u'小音', u'小体']

 myfont = font_manager.FontProperties(fname=u'C:\Windows\Fonts\时尚中黑简体.ttf')

数据提取

 student_0 = score_array[:,0]
 student_1 = score_array[:,1]
 student_2 = score_array[:,2]
 student_3 = score_array[:,3]
 student_4 = score_array[:,4]
 student_5 = score_array[:,5]

 bar_width = 0.1
 x_0 = list(range(len(students)))
 x_1 = [i + bar_width for i in x_0]
 x_2 = [i + bar_width * 2 for i in x_0]
 x_3 = [i + bar_width * 3 for i in x_0]
 x_4 = [i + bar_width * 4 for i in x_0]
 x_5 = [i + bar_width * 5 for i in x_0]

作图

 pt.figure(figsize=(12, 5),dpi=80)
 ax = pt.subplot(111)

 ax.set_title('Score')
 ax.set_xlabel('Students')
 ax.set_ylabel('y')

 pt.bar(range(len(students)), student_0, width=bar_width, label=courses[0])
 pt.bar(x_1, student_1, width=bar_width, label=courses[1])
 pt.bar(x_2, student_2, width=bar_width, label=courses[2])
 pt.bar(x_3, student_3, width=bar_width, label=courses[3])
 pt.bar(x_4, student_4, width=bar_width, label=courses[4])
 pt.bar(x_5, student_5, width=bar_width, label=courses[5])

 pt.legend(prop=myfont)
 pt.xticks([i + bar_width * 2.5 for i in x_0], students, fontproperties=myfont)
 pt.show()