Python数据分析之Matplotlib-II

6 基本图表绘制 plt.plot()

函数 说明
plt.plot(x, y, fmt,...) 绘制一个坐标图
plt.boxplot(data, notch, position) 绘制一个箱型图
plt.bar(left, height, width, bottom) 绘制一个条形图
plt.barh(width, bottom, left, height) 绘制一个横向条形图
plt.polar(theta, r) 绘制极坐标图
plt.pie(data, explode) 绘制饼图
plt.psd(x, NFFT=256, pad_to, Fs) 绘制功率谱密度图
plt.specgram(x, NFFT=256, pad_to, F) 绘制谱图
plt.cohere(x, y, NFFT=256, Fs) 绘制X-Y的相关性函数
plt.scatter(x, y) 绘制散点图,其中,x和y长度相同
plt.step(x, y, where) 绘制步阶图
plt.hist(x, bins, normed) 绘制直方图
plt.contour(X, Y, Z, N) 绘制等值图
plt.vlines() 绘制垂直图
plt.stem(x, y, linefmt, markerfmt) 绘制柴火图
plt.plot_date() 绘制数据日期
  • 图表类别:线形图、柱状图、密度图,以横纵坐标两个维度为主
plt.plot(kind = 'line', ax = None, figsize = None, use_index = True, title = None, grid = None, legend = False, style = None, logx = False, logy = False, loglog = False, xticks = None, yticks = None, xlim = None, ylim = None, rot = None, fontsize = None, colormap = None, table = False, yerr = None, xerr = None, label = None, secondary_y = False, **kwds)

6.1 Series直接生成图表

ts = pd.Series(np.random.randn(1000), index=pd.date_range('1/1/2000', periods = 1000))
ts = ts.cumsum()
ts.plot(kind='line',
       label = 'hehe',
       style = '--g.',
       color = 'red',
       alpha = 0.4,
       use_index = True,
       rot = 45,
       grid = True,
       ylim = [-50, 50],
       yticks = list(range(-50, 50, 10)),
       figsize = (8, 4),
       title = 'test',
       legend = True)
plt.grid(True, linestyle = "--", color = "gray", linewidth = "0.5", axis = 'x')  # 网格
plt.legend()
# Series.plot():series的index为横坐标,value为纵坐标
# kind → line,bar,barh...(折线图,柱状图,柱状图-横...)
# label → 图例标签,Dataframe格式以列名为label
# style → 风格字符串,这里包括了linestyle(-),marker(.),color(g)
# color → 颜色,有color指定时候,以color颜色为准
# alpha → 透明度,0-1
# use_index → 将索引用为刻度标签,默认为True
# rot → 旋转刻度标签,0-360
# grid → 显示网格,一般直接用plt.grid
# xlim,ylim → x,y轴界限
# xticks,yticks → x,y轴刻度值
# figsize → 图像大小
# title → 图名
# legend → 是否显示图例,一般直接用plt.legend()

Python数据分析之Matplotlib-II

6.2 DataFrame直接生成图表

df = pd.DataFrame(np.random.randn(1000, 4), index=ts.index, columns=list('ABCD'))
df = df.cumsum()
df.plot(kind='line',
       style = '--.',
       alpha = 0.4,
       use_index = True,
       rot = 45,
       grid = True,
       figsize = (8, 4),
       title = 'test',
       legend = True,
       subplots = False,
       colormap = 'Greens')
# subplots → 是否将各个列绘制到不同图表,默认False

Python数据分析之Matplotlib-II

7 柱状图与堆叠图

fig,axes = plt.subplots(4,1,figsize = (10, 10))
s = pd.Series(np.random.randint(0, 10, 16),index = list('abcdefghijklmnop'))  
df = pd.DataFrame(np.random.rand(10, 3), columns=['a', 'b', 'c'])

# 单系列柱状图:plt.plot(kind = 'bat/barh')
s.plot(kind = 'bar', color = 'k', grid = True, alpha = 0.5, ax = axes[0])# ax参数:选择第几个子图

# 多系列柱状图
df = pd.DataFrame(np.random.rand(10, 3), columns = ['a', 'b', 'c'])
df.plot(kind = 'bar', ax = axes[1], grid = True, colormap = 'Reds_r')

# 多系列堆叠图
df.plot(kind = 'bar', ax = axes[2], grid = True, colormap = 'Blues_r', stacked = True)

# 水平向
df.plot.barh(ax = axes[3], grid = True, stacked = True, colormap = 'BuGn_r')

Python数据分析之Matplotlib-II

7.1 柱状图 plt.bar()

plt.figure(figsize = (10, 4))
x = np.arange(10)
y1 = np.random.rand(10)
y2 = -np.random.rand(10)

plt.bar(x, y1, width = 1, facecolor = 'yellowgreen', edgecolor = 'white', yerr = y1 * 0.1)
plt.bar(x, y2, width = 1, facecolor = 'lightskyblue', edgecolor = 'white', yerr = y2 * 0.1)
# x,y参数:x,y值
# width:宽度比例
# facecolor柱状图里填充的颜色、edgecolor是边框的颜色
# left-每个柱x轴左边界,bottom-每个柱y轴下边界 → bottom扩展即可化为甘特图 Gantt Chart
# align:决定整个bar图分布,默认left表示默认从左边界开始绘制,center会将图绘制在中间位置
# xerr/yerr :x/y方向error bar
# 给图添加text
for i, j in zip(x, y1):
    plt.text(i + 0.3, j-0.15,'%.2f' % j, color = 'white')
for i, j in zip(x, y2):
    plt.text(i + 0.3, j+0.05,'%.2f' % -j, color = 'white')
# zip() 函数用于将可迭代的对象作为参数,将对象中对应的元素打包成一个个元组,然后返回由这些元组组成的列表。

Python数据分析之Matplotlib-II

7.2 堆叠图

# 外嵌图表plt.table()
# table(cellText=None, cellColours=None,cellLoc='right', colWidths=None,rowLabels=None, rowColours=None, rowLoc='left',
# colLabels=None, colColours=None, colLoc='center',loc='bottom', bbox=None)

data = [[ 66386, 174296,  75131, 577908,  32015],
        [ 58230, 381139,  78045,  99308, 160454],
        [ 89135,  80552, 152558, 497981, 603535],
        [ 78415,  81858, 150656, 193263,  69638],
        [139361, 331509, 343164, 781380,  52269]]
columns = ('Freeze', 'Wind', 'Flood', 'Quake', 'Hail')
rows = ['%d year' % x for x in (100, 50, 20, 10, 5)]
df = pd.DataFrame(data, columns = ('Freeze', 'Wind', 'Flood', 'Quake', 'Hail'),
                 index = ['%d year' % x for x in (100, 50, 20, 10, 5)])
print(df)

# 创建堆叠图
df.plot(kind = 'bar', grid = True,colormap = 'Blues_r', stacked = True, figsize = (8, 3))

plt.table(cellText = data,
          cellLoc = 'center',
          cellColours = None,
          rowLabels = rows,
          rowColours = plt.cm.BuPu(np.linspace(0, 0.5, 5))[::-1],  # BuPu可替换成其他colormap
          colLabels = columns,
          colColours = plt.cm.Reds(np.linspace(0, 0.5, 5))[::-1], 
          rowLoc='right',
          loc='bottom')
# cellText:表格文本
# cellLoc:cell内文本对齐位置
# rowLabels:行标签
# colLabels:列标签
# rowLoc:行标签对齐位置
# loc:表格位置 → left,right,top,bottom

plt.xticks([])# 不显示x轴标注

Python数据分析之Matplotlib-II

8 面积图、填图

8.1 面积图

fig, axes = plt.subplots(2, 1, figsize = (8,6))
df1 = pd.DataFrame(np.random.rand(10, 4), columns=['a', 'b', 'c', 'd'])
df2 = pd.DataFrame(np.random.randn(10, 4), columns=['a', 'b', 'c', 'd'])

df1.plot.area(colormap = 'Greens_r',alpha = 0.5, ax = axes[0])
df2.plot.area(stacked=False, colormap = 'Set2',alpha = 0.5, ax = axes[1])
# 使用Series.plot.area()和DataFrame.plot.area()创建面积图
# stacked:是否堆叠,默认情况下,区域图被堆叠
# 为了产生堆积面积图,每列必须是正值或全部负值!
# 当数据有NaN时候,自动填充0,所以图标签需要清洗掉缺失值

Python数据分析之Matplotlib-II

8.2 填图

fig,axes = plt.subplots(2, 1, figsize = (8, 6))

x = np.linspace(0, 1, 500)
y1 = np.sin(4 * np.pi * x) * np.exp(-5 * x)
y2 = -np.sin(4 * np.pi * x) * np.exp(-5 * x)
axes[0].fill(x, y1, 'r', alpha = 0.5, label = 'y1')
axes[0].fill(x, y2, 'g', alpha = 0.5, label = 'y2')
# 对函数与坐标轴之间的区域进行填充,使用fill函数
# 也可写成:plt.fill(x, y1, 'r',x, y2, 'g',alpha=0.5)

x = np.linspace(0, 5 * np.pi, 1000) 
y1 = np.sin(x)  
y2 = np.sin(2 * x)  
# 填充两个函数之间的区域,使用fill_between函数
axes[1].fill_between(x, y1, y2, color = 'b', alpha=0.5, label = 'area')  

# 添加图例、格网
for i in range(2):
    axes[i].legend()
    axes[i].grid()

Python数据分析之Matplotlib-II

8.3 饼图 plt.pie()

plt.pie(x, explode=None, labels=None, colors=None, autopct=None, pctdistance=0.6, shadow=False, labeldistance=1.1, startangle=None, radius=None, counterclock=True, wedgeprops=None, textprops=None, center=(0, 0), frame=False, hold=None, data=None)
  • explode:指定每部分的偏移量
  • labels:标签
  • colors:颜色
  • autopct:饼图上的数据标签显示方式
  • pctdistance:每个饼切片的中心和通过autopct生成的文本开始之间的比例
  • labeldistance:被画饼标记的直径,默认值:1.1
  • shadow:阴影
  • startangle:开始角度
  • radius:半径
  • frame:图框
  • counterclock:指定指针方向,顺时针或者逆时针
s = pd.Series(3 * np.random.rand(4), index=['a', 'b', 'c', 'd'], name='series')
plt.axis('equal')  # 保证长宽相等
plt.pie(s,
       explode = [0.1,0,0,0],
       labels = s.index,
       colors = ['r', 'g', 'b', 'c'],
       autopct = '%.2f%%',
       pctdistance = 0.6,
       labeldistance = 1.2,
       shadow = True,
       startangle = 0,
       radius = 1.5,
       frame = False)
print(s)

Python数据分析之Matplotlib-II

9 直方图、密度图

9.1 直方图

# 直方图
s = pd.Series(np.random.randn(1000))
s.hist(bins = 20,
       histtype = 'bar',
       align = 'mid',
       orientation = 'vertical',
       alpha = 0.5,
       density = True)
# bin:箱子的宽度
# normed 标准化
# histtype 风格,bar,barstacked,step,stepfilled
# orientation 水平还是垂直{‘horizontal’, ‘vertical’}
# align : {‘left’, ‘mid’, ‘right’}, optional(对齐方式)

# 密度图
s.plot(kind = 'kde', style = 'k--')

9.2 堆叠直方图

  • 使用DataFrame.plot.hist()Series.plot.hist()方法绘制
  • stacked:是否堆叠
plt.figure(num = 1)
df = pd.DataFrame({'a': np.random.randn(1000) + 1, 'b': np.random.randn(1000),
                    'c': np.random.randn(1000) - 1, 'd': np.random.randn(1000) - 2},
                   columns = ['a', 'b', 'c', 'd'])
df.plot.hist(stacked = True,
             bins = 20,
             colormap = 'Greens_r',
             alpha = 0.5,
             grid = True)

# 生成多个直方图
df.hist(bins = 50)

Python数据分析之Matplotlib-II

10 散点图、矩阵散点图

  • plt.scatter(),pd.scatter_matrix()
fig, ax = plt.subplots()
ax.plot(10 * np.random.randn(100), 10 * np.random.randn(100), 'o')
ax.set_title('Simple Scatter')

Python数据分析之Matplotlib-II

10.1 散点图plt.scatter()

plt.scatter(x, y, s = 20, c = None, marker = 'o', cmap = None, norm = None, vmin = None, vmax = None, alpha = None, linewidths = None, verts = None, edgecolors = None, hold = None, data = None, **kwargs)

plt.figure(figsize = (8, 6))
x = np.random.randn(1000)
y = np.random.randn(1000)
plt.scatter(x,y,marker = '.',
           s = np.random.randn(1000) * 100,
           cmap = 'Reds',
           c = y,
           alpha = 0.8)
plt.grid()
# s:散点的大小
# c:散点的颜色
# vmin, vmax:亮度设置,标量
# cmap:colormap

Python数据分析之Matplotlib-II

10.2 散点矩阵

pd.plotting.scatter_matrix(frame, alpha = 0.5, figsize = None, ax = None, grid = False, diagonal = 'hist', marker = '.', density_kwds = None, hist_kwds = None, range_padding = 0.05, **kwds)

df = pd.DataFrame(np.random.randn(100,4),columns = ['a','b','c','d'])
pd.plotting.scatter_matrix(df, figsize=(10,6),
                 marker = 'o',
                 diagonal = 'kde',
                 alpha = 0.5,
                 range_padding = 0.1)
# diagonal:({‘hist’, ‘kde’}),必须且只能在{‘hist’, ‘kde’}中选择1个 → 每个指标的频率图
# range_padding:(float, 可选),图像在x轴、y轴原点附近的留白(padding),该值越大,留白距离越大,图像远离坐标原点

Python数据分析之Matplotlib-II

11 极坐标图

  • 调用subplot()创建子图时通过设置projection='polar',便可创建一个极坐标子图,然后调用plot()在极坐标子图中绘图
N = 20
theta = np.linspace(0.0, 2 * np.pi, N, endpoint = False)
radii = 10 * np.random.rand(N)
width = np.pi / 4 * np.random.rand(N)

ax = plt.subplot(111, projection = 'polar')
bars = ax.bar(theta, radii, width = width, bottom = 0.0)

for r, bar in zip(radii, bars):
    bar.set_facecolor(plt.cm.viridis(r / 10.))
    bar.set_alpha(0.5)
plt.show()

Python数据分析之Matplotlib-II

# 创建数据
s = pd.Series(np.arange(20))
theta=np.arange(0, 2 * np.pi, 0.02)
print(s.head())
print(theta[:10])

# 创建极坐标子图
fig = plt.figure(figsize = (8, 4))
ax1 = plt.subplot(121, projection = 'polar')
ax2 = plt.subplot(122)
# 还可以写:ax = fig.add_subplot(111, polar = True)

# 创建极坐标图,参数1为角度(弧度制),参数2为value
ax1.plot(theta, theta * 3, linestyle = '--', lw = 1)  
ax1.plot(s, linestyle = '--', marker = '.', lw = 2)
ax2.plot(theta, theta * 3, inestyle = '--', lw = 1)
ax2.plot(s)
plt.grid()
# lw → 线宽

Python数据分析之Matplotlib-II

11.1 极坐标参数设置

# 创建极坐标子图ax
theta=np.arange(0, 2*np.pi, 0.02)
plt.figure(figsize = (8, 4))
ax1= plt.subplot(121, projection = 'polar')
ax2= plt.subplot(122, projection = 'polar')
ax1.plot(theta, theta / 6, '--', lw = 2)
ax2.plot(theta, theta / 6, '--', lw = 2)

# set_theta_direction():坐标轴正方向,默认逆时针

ax2.set_theta_direction(-1)

# set_thetagrids():设置极坐标角度网格线显示及标签 → 网格和标签数量一致
# set_rgrids():设置极径网格线显示,其中参数必须是正数
ax2.set_thetagrids(np.arange(0.0, 360.0, 90),['a', 'b', 'c', 'd'])
ax2.set_rgrids(np.arange(0.2, 2, 0.4))

# set_theta_offset():设置角度偏移,逆时针,弧度制
ax2.set_theta_offset(np.pi / 2)

# set_rlim():设置显示的极径范围
# set_rmax():设置显示的极径最大值
# set_rticks():设置极径网格线的显示范围
ax2.set_rlim(0.2, 1.2)
ax2.set_rmax(2)
ax2.set_rticks(np.arange(0.1, 1.5, 0.2))

Python数据分析之Matplotlib-II

11.2 雷达图1

  • 极坐标的折线图/填图 - plt.plot()
plt.figure(figsize=(8, 4))

ax1= plt.subplot(111, projection='polar')
ax1.set_title('radar map\n')  # 创建标题
ax1.set_rlim(0,12)

# 创建数据
data1 = np.random.randint(1, 10, 10)
data2 = np.random.randint(1, 10, 10)
data3 = np.random.randint(1, 10, 10)
theta=np.arange(0, 2 * np.pi, 2 * np.pi / 10)

# 绘制雷达线
ax1.plot(theta, data1, '.--', label = 'data1')
ax1.fill(theta, data1, alpha = 0.2)
ax1.plot(theta, data2,'.--', label = 'data2')
ax1.fill(theta, data2, alpha=0.2)
ax1.plot(theta, data3,'.--', label = 'data3')
ax1.fill(theta, data3, alpha = 0.2)

Python数据分析之Matplotlib-II

11.3 雷达图2

11.3.1 极坐标的折线图/填图 - plt.polar()

  • 首尾闭合
labels = np.array(['a', 'b', 'c', 'd', 'e', 'f']) # 标签
dataLenth = 6 # 数据长度
data1 = np.random.randint(0, 10, 6) 
data2 = np.random.randint(0, 10, 6) # 数据

angles = np.linspace(0, 2 * np.pi, dataLenth, endpoint = False) # 分割圆周长
data1 = np.concatenate((data1, [data1[0]])) # 闭合
data2 = np.concatenate((data2, [data2[0]])) # 闭合
angles = np.concatenate((angles, [angles[0]])) # 闭合

plt.polar(angles, data1, 'o-', linewidth = 1) #做极坐标系
plt.fill(angles, data1, alpha = 0.25) # 填充
plt.polar(angles, data2, 'o-', linewidth = 1) #做极坐标系
plt.fill(angles, data2, alpha = 0.25)# 填充

plt.thetagrids(angles * 180 / np.pi, labels) # 设置网格、标签
plt.ylim(0, 10)  # polar的极值设置为ylim

Python数据分析之Matplotlib-II

11.3.2 极轴图 - 极坐标的柱状图

plt.figure(figsize = (8, 4))

ax1= plt.subplot(111, projection = 'polar')
ax1.set_title('radar map\n')
ax1.set_rlim(0, 12)

# 创建数据
data = np.random.randint(1, 10, 10)
theta=np.arange(0, 2 * np.pi, 2 * np.pi / 10)


bar = ax1.bar(theta, data, alpha = 0.5)
for r, bar in zip(data, bar):
    bar.set_facecolor(plt.cm.jet(r / 10.))  # 设置颜色
plt.thetagrids(np.arange(0.0, 360.0, 90), []) # 设置网格、标签(这里是空标签,则不显示内容)

Python数据分析之Matplotlib-II

12 箱型图

  • 箱型图:又称为盒须图、盒式图、盒状图或箱线图,是一种用作显示一组数据分散情况资料的统计图
  • 包含一组数据的:最大值、最小值、中位数、上四分位数(Q1)、下四分位数(Q3)、异常值
    1. 中位数 → 一组数据平均分成两份,中间的数
    2. 下四分位数Q1 → 是将序列平均分成四份,计算(n+1)/4与(n-1)/4两种,一般使用(n+1)/4
    3. 上四分位数Q3 → 是将序列平均分成四份,计算(1+n)/4*3=6.75
    4. 内限 → T形的盒须就是内限,最大值区间Q3+1.5IQR,最小值区间Q1-1.5IQR (IQR=Q3-Q1)
    5. 外限 → T形的盒须就是内限,最大值区间Q3+3IQR,最小值区间Q1-3IQR (IQR=Q3-Q1)
    6. 异常值 → 内限之外 - 中度异常,外限之外 - 极度异常
  • plt.boxplot()绘制
pltboxplot(x, notch=None, sym=None, vert=None, whis=None, positions=None, widths=None, patch_artist=None, bootstrap=None, 
usermedians=None, conf_intervals=None, meanline=None, showmeans=None, showcaps=None, showbox=None, showfliers=None, boxprops=None, 
labels=None, flierprops=None, medianprops=None, meanprops=None, capprops=None, whiskerprops=None, manage_xticks=True, autorange=False, 
zorder=None, hold=None, data=None)
fig, axes = plt.subplots(2, 1, figsize=(10, 6))
df = pd.DataFrame(np.random.rand(10, 5), columns=['A', 'B', 'C', 'D', 'E'])
color = dict(boxes='DarkGreen', whiskers='DarkOrange', medians='DarkBlue', caps='Gray')
# 箱型图着色
# boxes → 箱线
# whiskers → 分位数与error bar横线之间竖线的颜色
# medians → 中位数线颜色
# caps → error bar横线颜色

df.plot.box(ylim = [0, 1.2],
           grid = True,
           color = color,
           ax = axes[0])
# color:样式填充

df.plot.box(vert = False, 
            positions = [1, 4, 5, 6, 8],
            ax = axes[1],
            grid = True,
            color = color)
# vert:是否垂直,默认True
# position:箱型图占位

Python数据分析之Matplotlib-II

# 创建图表、数据
df = pd.DataFrame(np.random.rand(10, 5), columns=['A', 'B', 'C', 'D', 'E'])
plt.figure(figsize=(10,4))

f = df.boxplot(sym = 'o',  # 异常点形状,参考marker
               vert = True,  # 是否垂直
               whis = 1.5,  # IQR,默认1.5,也可以设置区间比如[5,95],代表强制上下边缘为数据95%和5%位置
               patch_artist = True,  # 上下四分位框内是否填充,True为填充
               meanline = False,showmeans=True,  # 是否有均值线及其形状
               showbox = True,  # 是否显示箱线
               showcaps = True,  # 是否显示边缘线
               showfliers = True,  # 是否显示异常值
               notch = False,  # 中间箱体是否缺口
               return_type='dict'  # 返回类型为字典
              ) 
plt.title('boxplot')
print(f)

for box in f['boxes']:
    box.set( color = 'b', linewidth = 1)        # 箱体边框颜色
    box.set( facecolor = 'b', alpha = 0.5)    # 箱体内部填充颜色
for whisker in f['whiskers']:
    whisker.set(color = 'k', linewidth = 0.5, linestyle = '-')
for cap in f['caps']:
    cap.set(color = 'gray', linewidth = 2)
for median in f['medians']:
    median.set(color = 'DarkBlue', linewidth = 2)
for flier in f['fliers']:
    flier.set(marker = 'o', color = 'y', alpha = 0.5)
# boxes, 箱线
# medians, 中位值的横线,
# whiskers, 从box到error bar之间的竖线.
# fliers, 异常值
# caps, error bar横线
# means, 均值的横线

Python数据分析之Matplotlib-II

# 分组汇总
df = pd.DataFrame(np.random.rand(10, 2), columns = ['Col1', 'Col2'] )
df['X'] = pd.Series(['A', 'A', 'A', 'A', 'A', 'B', 'B', 'B', 'B', 'B'])
df['Y'] = pd.Series(['A', 'B', 'A', 'B', 'A', 'B', 'A', 'B', 'A', 'B'])
print(df.head())
df.boxplot(by = 'X')
df.boxplot(column = ['Col1', 'Col2'], by=['X', 'Y'])
# columns:按照数据的列分子图
# by:按照列分组做箱型图

Python数据分析之Matplotlib-II