Python 數據分析三劍客之 Matplotlib(十一):最常用最有價值的 50 個圖表

娛樂小視頻:小黃人番外短片合集 — 第17集【Yellow is the New Black 小黃人越獄計劃】


Matplotlib 系列文章:


翻譯丨TRHX
作者丨Selva Prabhakaran
原文丨《Top 50 matplotlib Visualizations – The Master Plots (with full python code)》


★ 本文中的示例原作者使用的編輯器爲 Jupyter Notebook;

★ 譯者使用 PyCharm 測試原文中有部分代碼不太準確,部分已進行修改,對應有註釋說明;

★ 運行本文代碼,需要安裝 Matplotlib 和 Seaborn 等可視化庫,其他的一些輔助可視化庫已在代碼部分作標註;

★ 示例中用到的數據均儲存在作者的 GitHub:https://github.com/selva86/datasets,因此運行程序可能需要FQ;

★ 譯者英文水平有限,若遇到翻譯模糊的詞建議參考原文來理解。

★ 本文50個示例代碼已打包爲 .py 文件,可直接下載:https://download.csdn.net/download/qq_36759224/12507219


文章目錄


這裏是一段防爬蟲文本,請讀者忽略。
本譯文首發於 CSDN,作者 Selva Prabhakaran,譯者 TRHX。
本文鏈接:https://itrhx.blog.csdn.net/article/details/106558131
原文鏈接:https://www.machinelearningplus.com/plots/top-50-matplotlib-visualizations-the-master-plots-python/

【1x00】介紹(Introduction)

在數據分析和可視化中最常用的、最有價值的前 50 個 Matplotlib 圖表。這些圖表會讓你懂得在不同情況下合理使用 Python 的 Matplotlib 和 Seaborn 庫來達到數據可視化效果。

這些圖表根據可視化目標的 7 個不同情景進行分組。 例如,如果要想象兩個變量之間的關係,請查看“關聯”部分下的圖表。 或者,如果您想要顯示值如何隨時間變化,請查看“變化”部分,依此類推。

有效圖表的重要特徵:

  • 在不歪曲事實的情況下傳達正確和必要的信息;
  • 設計簡單,不必太費力就能理解它;
  • 從審美角度支持信息而不是掩蓋信息;
  • 信息沒有超負荷。

【2x00】準備工作(Setup)

在代碼運行前先引入下面的基本設置,當然,個別圖表可能會重新定義顯示要素。

# !pip install brewer2mpl
import numpy as np
import pandas as pd
import matplotlib as mpl
import matplotlib.pyplot as plt
import seaborn as sns
import warnings; warnings.filterwarnings(action='once')

large = 22; med = 16; small = 12
params = {'axes.titlesize': large,
          'legend.fontsize': med,
          'figure.figsize': (16, 10),
          'axes.labelsize': med,
          'axes.titlesize': med,
          'xtick.labelsize': med,
          'ytick.labelsize': med,
          'figure.titlesize': large}
plt.rcParams.update(params)
plt.style.use('seaborn-whitegrid')
sns.set_style("white")
%matplotlib inline

# Version
print(mpl.__version__)  #> 3.0.0
print(sns.__version__)  #> 0.9.0

【3x00】關聯(Correlation)

關聯圖用於可視化兩個或多個變量之間的關係。也就是說,一個變量相對於另一個變量如何變化。

【01】散點圖(Scatter plot)

散點圖是研究兩個變量之間關係的經典和基本的繪圖。如果數據中有多個組,則可能需要以不同的顏色顯示每個組。在 Matplotlib 中,您可以使用 plt.scatterplot() 方便地執行此操作。

# Import dataset 
midwest = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/midwest_filter.csv")

# Prepare Data 
# Create as many colors as there are unique midwest['category']
categories = np.unique(midwest['category'])
colors = [plt.cm.tab10(i/float(len(categories)-1)) for i in range(len(categories))]

# Draw Plot for Each Category
plt.figure(figsize=(16, 10), dpi= 80, facecolor='w', edgecolor='k')

for i, category in enumerate(categories):
    plt.scatter('area', 'poptotal', 
                data=midwest.loc[midwest.category==category, :], 
                s=20, cmap=colors[i], label=str(category))
# 原文 c=colors[i] 已修改爲 cmap=colors[i]

# Decorations
plt.gca().set(xlim=(0.0, 0.1), ylim=(0, 90000),
              xlabel='Area', ylabel='Population')

plt.xticks(fontsize=12); plt.yticks(fontsize=12)
plt.title("Scatterplot of Midwest Area vs Population", fontsize=22)
plt.legend(fontsize=12)    
plt.show()    

01

【02】帶邊界的氣泡圖(Bubble plot with Encircling)

有時候您想在一個邊界內顯示一組點來強調它們的重要性。在本例中,您將從被包圍的數據中獲取記錄,並將其傳遞給下面的代碼中描述的 encircle()

from matplotlib import patches
from scipy.spatial import ConvexHull
import warnings; warnings.simplefilter('ignore')
sns.set_style("white")

# Step 1: Prepare Data
midwest = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/midwest_filter.csv")

# As many colors as there are unique midwest['category']
categories = np.unique(midwest['category'])
colors = [plt.cm.tab10(i/float(len(categories)-1)) for i in range(len(categories))]

# Step 2: Draw Scatterplot with unique color for each category
fig = plt.figure(figsize=(16, 10), dpi=80, facecolor='w', edgecolor='k')

for i, category in enumerate(categories):
    plt.scatter('area', 'poptotal', data=midwest.loc[midwest.category == category, :], s='dot_size', cmap=colors[i], label=str(category), edgecolors='black', linewidths=.5)
# 原文 c=colors[i] 已修改爲 cmap=colors[i]

# Step 3: Encircling
# https://stackoverflow.com/questions/44575681/how-do-i-encircle-different-data-sets-in-scatter-plot
def encircle(x,y, ax=None, **kw):
    if not ax: ax = plt.gca()
    p = np.c_[x, y]
    hull = ConvexHull(p)
    poly = plt.Polygon(p[hull.vertices, :], **kw)
    ax.add_patch(poly)

# Select data to be encircled
midwest_encircle_data = midwest.loc[midwest.state=='IN', :]

# Draw polygon surrounding vertices
encircle(midwest_encircle_data.area, midwest_encircle_data.poptotal, ec="k", fc="gold", alpha=0.1)
encircle(midwest_encircle_data.area, midwest_encircle_data.poptotal, ec="firebrick", fc="none", linewidth=1.5)

# Step 4: Decorations
plt.gca().set(xlim=(0.0, 0.1), ylim=(0, 90000),
              xlabel='Area', ylabel='Population')

plt.xticks(fontsize=12); plt.yticks(fontsize=12)
plt.title("Bubble Plot with Encircling", fontsize=22)
plt.legend(fontsize=12)
plt.show()

02

【03】帶線性迴歸最佳擬合線的散點圖(Scatter plot with linear regression line of best fit)

如果你想了解兩個變量之間是如何變化的,那麼最佳擬合線就是常用的方法。下圖顯示了數據中不同組之間的最佳擬合線的差異。若要禁用分組並只爲整個數據集繪製一條最佳擬合線,請從 sns.lmplot() 方法中刪除 hue ='cyl' 參數。

# Import Data
df = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/mpg_ggplot2.csv")
df_select = df.loc[df.cyl.isin([4, 8]), :]

# Plot
sns.set_style("white")
gridobj = sns.lmplot(x="displ", y="hwy", hue="cyl", data=df_select,
                     height=7, aspect=1.6, robust=True, palette='tab10',
                     scatter_kws=dict(s=60, linewidths=.7, edgecolors='black'))

# Decorations
gridobj.set(xlim=(0.5, 7.5), ylim=(0, 50))
plt.title("Scatterplot with line of best fit grouped by number of cylinders", fontsize=20)
plt.show()

03

針對每一組數據繪製線性迴歸線(Each regression line in its own column),可以通過在 sns.lmplot() 中設置 col=groupingcolumn 參數來實現,如下:

# Import Data
df = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/mpg_ggplot2.csv")
df_select = df.loc[df.cyl.isin([4, 8]), :]

# Each line in its own column
sns.set_style("white")
gridobj = sns.lmplot(x="displ", y="hwy",
                     data=df_select,
                     height=7,
                     robust=True,
                     palette='Set1',
                     col="cyl",
                     scatter_kws=dict(s=60, linewidths=.7, edgecolors='black'))

# Decorations
gridobj.set(xlim=(0.5, 7.5), ylim=(0, 50))
plt.show()

04

【04】抖動圖(Jittering with stripplot)

通常,多個數據點具有完全相同的 X 和 Y 值。 此時多個點繪製會重疊並隱藏。爲避免這種情況,可以將數據點稍微抖動,以便可以直觀地看到它們。 使用 seaborn 庫的 stripplot() 方法可以很方便的實現這個功能。

# Import Data
df = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/mpg_ggplot2.csv")

# Draw Stripplot
fig, ax = plt.subplots(figsize=(16,10), dpi= 80)
sns.stripplot(df.cty, df.hwy, jitter=0.25, size=8, ax=ax, linewidth=.5)

# Decorations
plt.title('Use jittered plots to avoid overlapping of points', fontsize=22)
plt.show()

05

【05】計數圖(Counts Plot)

避免點重疊問題的另一個選擇是根據點的位置增加點的大小。所以,點的大小越大,它周圍的點就越集中。

# Import Data
df = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/mpg_ggplot2.csv")
df_counts = df.groupby(['hwy', 'cty']).size().reset_index(name='counts')

# Draw Stripplot
fig, ax = plt.subplots(figsize=(16,10), dpi= 80)    
sns.stripplot(df_counts.cty, df_counts.hwy, size=df_counts.counts*2, ax=ax)

# Decorations
plt.title('Counts Plot - Size of circle is bigger as more points overlap', fontsize=22)
plt.show()

06

【06】邊緣直方圖(Marginal Histogram)

邊緣直方圖是具有沿 X 和 Y 軸變量的直方圖。 這用於可視化 X 和 Y 之間的關係以及單獨的 X 和 Y 的單變量分佈。 這種圖經常用於探索性數據分析(EDA)。

# Import Data
df = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/mpg_ggplot2.csv")

# Create Fig and gridspec
fig = plt.figure(figsize=(16, 10), dpi= 80)
grid = plt.GridSpec(4, 4, hspace=0.5, wspace=0.2)

# Define the axes
ax_main = fig.add_subplot(grid[:-1, :-1])
ax_right = fig.add_subplot(grid[:-1, -1], xticklabels=[], yticklabels=[])
ax_bottom = fig.add_subplot(grid[-1, 0:-1], xticklabels=[], yticklabels=[])

# Scatterplot on main ax
ax_main.scatter('displ', 'hwy', s=df.cty*4, c=df.manufacturer.astype('category').cat.codes, alpha=.9, data=df, cmap="tab10", edgecolors='gray', linewidths=.5)

# histogram on the right
ax_bottom.hist(df.displ, 40, histtype='stepfilled', orientation='vertical', color='deeppink')
ax_bottom.invert_yaxis()

# histogram in the bottom
ax_right.hist(df.hwy, 40, histtype='stepfilled', orientation='horizontal', color='deeppink')

# Decorations
ax_main.set(title='Scatterplot with Histograms \n displ vs hwy', xlabel='displ', ylabel='hwy')
ax_main.title.set_fontsize(20)
for item in ([ax_main.xaxis.label, ax_main.yaxis.label] + ax_main.get_xticklabels() + ax_main.get_yticklabels()):
    item.set_fontsize(14)

xlabels = ax_main.get_xticks().tolist()
ax_main.set_xticklabels(xlabels)
plt.show()

07

【07】邊緣箱形圖(Marginal Boxplot)

邊緣箱形圖與邊緣直方圖具有相似的用途。 然而,箱線圖有助於精確定位 X 和 Y 的中位數、第25和第75百分位數。

# Import Data
df = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/mpg_ggplot2.csv")

# Create Fig and gridspec
fig = plt.figure(figsize=(16, 10), dpi= 80)
grid = plt.GridSpec(4, 4, hspace=0.5, wspace=0.2)

# Define the axes
ax_main = fig.add_subplot(grid[:-1, :-1])
ax_right = fig.add_subplot(grid[:-1, -1], xticklabels=[], yticklabels=[])
ax_bottom = fig.add_subplot(grid[-1, 0:-1], xticklabels=[], yticklabels=[])

# Scatterplot on main ax
ax_main.scatter('displ', 'hwy', s=df.cty*5, c=df.manufacturer.astype('category').cat.codes, alpha=.9, data=df, cmap="Set1", edgecolors='black', linewidths=.5)

# Add a graph in each part
sns.boxplot(df.hwy, ax=ax_right, orient="v")
sns.boxplot(df.displ, ax=ax_bottom, orient="h")

# Decorations ------------------
# Remove x axis name for the boxplot
ax_bottom.set(xlabel='')
ax_right.set(ylabel='')

# Main Title, Xlabel and YLabel
ax_main.set(title='Scatterplot with Histograms \n displ vs hwy', xlabel='displ', ylabel='hwy')

# Set font size of different components
ax_main.title.set_fontsize(20)
for item in ([ax_main.xaxis.label, ax_main.yaxis.label] + ax_main.get_xticklabels() + ax_main.get_yticklabels()):
    item.set_fontsize(14)

plt.show()

08

【08】相關圖(Correllogram)

相關圖用於直觀地查看給定數據幀(或二維數組)中所有可能的數值變量對之間的相關性度量。

# Import Dataset
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/mtcars.csv")

# Plot
plt.figure(figsize=(12, 10), dpi=80)
sns.heatmap(df.corr(), xticklabels=df.corr().columns, yticklabels=df.corr().columns, cmap='RdYlGn', center=0, annot=True)

# Decorations
plt.title('Correlogram of mtcars', fontsize=22)
plt.xticks(fontsize=12)
plt.yticks(fontsize=12)
plt.show()

09

【09】成對圖(Pairwise Plot)

成對圖是探索性分析中最受歡迎的一種方法,用來理解所有可能的數值變量對之間的關係。它是二元分析的必備工具。

# Load Dataset
df = sns.load_dataset('iris')

# Plot
plt.figure(figsize=(10, 8), dpi=80)
sns.pairplot(df, kind="scatter", hue="species", plot_kws=dict(s=80, edgecolor="white", linewidth=2.5))
plt.show()

10

# Load Dataset
df = sns.load_dataset('iris')

# Plot
plt.figure(figsize=(10, 8), dpi=80)
sns.pairplot(df, kind="reg", hue="species")
plt.show()

11

【4x00】偏差(Deviation)

【10】發散型條形圖(Diverging Bars)

如果您想根據單個指標查看項目的變化情況,並可視化此差異的順序和數量,那麼散型條形圖是一個很好的工具。 它有助於快速區分數據組的性能,並且非常直觀,並且可以立即傳達這一點。

# Prepare Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/mtcars.csv")
x = df.loc[:, ['mpg']]
df['mpg_z'] = (x - x.mean())/x.std()
df['colors'] = ['red' if x < 0 else 'green' for x in df['mpg_z']]
df.sort_values('mpg_z', inplace=True)
df.reset_index(inplace=True)

# Draw plot
plt.figure(figsize=(14,10), dpi= 80)
plt.hlines(y=df.index, xmin=0, xmax=df.mpg_z, color=df.colors, alpha=0.4, linewidth=5)

# Decorations
plt.gca().set(ylabel='$Model$', xlabel='$Mileage$')
plt.yticks(df.index, df.cars, fontsize=12)
plt.title('Diverging Bars of Car Mileage', fontdict={'size':20})
plt.grid(linestyle='--', alpha=0.5)
plt.show()

12

【11】發散型文本圖(Diverging Texts)

發散型文本圖與發散型條形圖相似,如果你希望以一種美觀的方式顯示圖表中每個項目的值,就可以使用這種方法。

# Prepare Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/mtcars.csv")
x = df.loc[:, ['mpg']]
df['mpg_z'] = (x - x.mean())/x.std()
df['colors'] = ['red' if x < 0 else 'green' for x in df['mpg_z']]
df.sort_values('mpg_z', inplace=True)
df.reset_index(inplace=True)

# Draw plot
plt.figure(figsize=(14, 14), dpi=80)
plt.hlines(y=df.index, xmin=0, xmax=df.mpg_z)
for x, y, tex in zip(df.mpg_z, df.index, df.mpg_z):
    t = plt.text(x, y, round(tex, 2), horizontalalignment='right' if x < 0 else 'left',
                 verticalalignment='center', fontdict={'color':'red' if x < 0 else 'green', 'size':14})

# Decorations
plt.yticks(df.index, df.cars, fontsize=12)
plt.title('Diverging Text Bars of Car Mileage', fontdict={'size':20})
plt.grid(linestyle='--', alpha=0.5)
plt.xlim(-2.5, 2.5)
plt.show()

13

【12】發散型散點圖(Diverging Dot Plot)

發散型散點圖類似於發散型條形圖。 但是,與發散型條形圖相比,沒有條形會減少組之間的對比度和差異。

# Prepare Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/mtcars.csv")
x = df.loc[:, ['mpg']]
df['mpg_z'] = (x - x.mean())/x.std()
df['colors'] = ['red' if x < 0 else 'darkgreen' for x in df['mpg_z']]
df.sort_values('mpg_z', inplace=True)
df.reset_index(inplace=True)

# Draw plot
plt.figure(figsize=(14, 16), dpi=80)
plt.scatter(df.mpg_z, df.index, s=450, alpha=.6, color=df.colors)
for x, y, tex in zip(df.mpg_z, df.index, df.mpg_z):
    t = plt.text(x, y, round(tex, 1), horizontalalignment='center',
                 verticalalignment='center', fontdict={'color': 'white'})

# Decorations
# Lighten borders
plt.gca().spines["top"].set_alpha(.3)
plt.gca().spines["bottom"].set_alpha(.3)
plt.gca().spines["right"].set_alpha(.3)
plt.gca().spines["left"].set_alpha(.3)

plt.yticks(df.index, df.cars)
plt.title('Diverging Dotplot of Car Mileage', fontdict={'size': 20})
plt.xlabel('$Mileage$')
plt.grid(linestyle='--', alpha=0.5)
plt.xlim(-2.5, 2.5)
plt.show()

14

【13】帶標記的發散型棒棒糖圖(Diverging Lollipop Chart with Markers)

帶有標記的棒棒糖提供了一種靈活的方式,強調您想要引起注意的任何重要數據點並在圖表中適當地給出推理。

# Prepare Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/mtcars.csv")
x = df.loc[:, ['mpg']]
df['mpg_z'] = (x - x.mean())/x.std()
df['colors'] = 'black'

# color fiat differently
df.loc[df.cars == 'Fiat X1-9', 'colors'] = 'darkorange'
df.sort_values('mpg_z', inplace=True)
df.reset_index(inplace=True)


# Draw plot
import matplotlib.patches as patches

plt.figure(figsize=(14, 16), dpi=80)
plt.hlines(y=df.index, xmin=0, xmax=df.mpg_z, color=df.colors, alpha=0.4, linewidth=1)
plt.scatter(df.mpg_z, df.index, color=df.colors, s=[600 if x == 'Fiat X1-9' else 300 for x in df.cars], alpha=0.6)
plt.yticks(df.index, df.cars)
plt.xticks(fontsize=12)

# Annotate
plt.annotate('Mercedes Models', xy=(0.0, 11.0), xytext=(1.0, 11), xycoords='data',
            fontsize=15, ha='center', va='center',
            bbox=dict(boxstyle='square', fc='firebrick'),
            arrowprops=dict(arrowstyle='-[, widthB=2.0, lengthB=1.5', lw=2.0, color='steelblue'), color='white')

# Add Patches
p1 = patches.Rectangle((-2.0, -1), width=.3, height=3, alpha=.2, facecolor='red')
p2 = patches.Rectangle((1.5, 27), width=.8, height=5, alpha=.2, facecolor='green')
plt.gca().add_patch(p1)
plt.gca().add_patch(p2)

# Decorate
plt.title('Diverging Bars of Car Mileage', fontdict={'size': 20})
plt.grid(linestyle='--', alpha=0.5)
plt.show()

15

【14】面積圖(Area Chart)

通過對軸和線之間的區域進行着色,面積圖不僅強調波峯和波谷,還強調波峯和波谷的持續時間。 高點持續時間越長,線下面積越大。

import numpy as np
import pandas as pd

# Prepare Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/economics.csv", parse_dates=['date']).head(100)
x = np.arange(df.shape[0])
y_returns = (df.psavert.diff().fillna(0)/df.psavert.shift(1)).fillna(0) * 100

# Plot
plt.figure(figsize=(16, 10), dpi=80)
plt.fill_between(x[1:], y_returns[1:], 0, where=y_returns[1:] >= 0, facecolor='green', interpolate=True, alpha=0.7)
plt.fill_between(x[1:], y_returns[1:], 0, where=y_returns[1:] <= 0, facecolor='red', interpolate=True, alpha=0.7)

# Annotate
plt.annotate('Peak \n1975', xy=(94.0, 21.0), xytext=(88.0, 28),
             bbox=dict(boxstyle='square', fc='firebrick'),
             arrowprops=dict(facecolor='steelblue', shrink=0.05), fontsize=15, color='white')


# Decorations
xtickvals = [str(m)[:3].upper()+"-"+str(y) for y, m in zip(df.date.dt.year, df.date.dt.month_name())]
plt.gca().set_xticks(x[::6])
plt.gca().set_xticklabels(xtickvals[::6], rotation=90, fontdict={'horizontalalignment': 'center', 'verticalalignment': 'center_baseline'})
plt.ylim(-35, 35)
plt.xlim(1, 100)
plt.title("Month Economics Return %", fontsize=22)
plt.ylabel('Monthly returns %')
plt.grid(alpha=0.5)
plt.show()

16

【5x00】排序(Ranking)

【15】有序條形圖(Ordered Bar Chart)

有序條形圖有效地傳達了項目的排序順序。在圖表上方添加度量標準的值,用戶就可以從圖表本身獲得精確的信息。

# Prepare Data
df_raw = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")
df = df_raw[['cty', 'manufacturer']].groupby('manufacturer').apply(lambda x: x.mean())
df.sort_values('cty', inplace=True)
df.reset_index(inplace=True)

# Draw plot
import matplotlib.patches as patches

fig, ax = plt.subplots(figsize=(16,10), facecolor='white', dpi= 80)
ax.vlines(x=df.index, ymin=0, ymax=df.cty, color='firebrick', alpha=0.7, linewidth=20)

# Annotate Text
for i, cty in enumerate(df.cty):
    ax.text(i, cty+0.5, round(cty, 1), horizontalalignment='center')


# Title, Label, Ticks and Ylim
ax.set_title('Bar Chart for Highway Mileage', fontdict={'size':22})
ax.set(ylabel='Miles Per Gallon', ylim=(0, 30))
plt.xticks(df.index, df.manufacturer.str.upper(), rotation=60, horizontalalignment='right', fontsize=12)

# Add patches to color the X axis labels
p1 = patches.Rectangle((.57, -0.005), width=.33, height=.13, alpha=.1, facecolor='green', transform=fig.transFigure)
p2 = patches.Rectangle((.124, -0.005), width=.446, height=.13, alpha=.1, facecolor='red', transform=fig.transFigure)
fig.add_artist(p1)
fig.add_artist(p2)
plt.show()

17

【16】棒棒糖圖(Lollipop Chart)

棒棒糖圖表以一種視覺上令人愉悅的方式提供與有序條形圖類似的目的。

# Prepare Data
df_raw = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")
df = df_raw[['cty', 'manufacturer']].groupby('manufacturer').apply(lambda x: x.mean())
df.sort_values('cty', inplace=True)
df.reset_index(inplace=True)

# Draw plot
fig, ax = plt.subplots(figsize=(16, 10), dpi=80)
ax.vlines(x=df.index, ymin=0, ymax=df.cty, color='firebrick', alpha=0.7, linewidth=2)
ax.scatter(x=df.index, y=df.cty, s=75, color='firebrick', alpha=0.7)

# Title, Label, Ticks and Ylim
ax.set_title('Lollipop Chart for Highway Mileage', fontdict={'size': 22})
ax.set_ylabel('Miles Per Gallon')
ax.set_xticks(df.index)
ax.set_xticklabels(df.manufacturer.str.upper(), rotation=60, fontdict={'horizontalalignment': 'right', 'size': 12})
ax.set_ylim(0, 30)

# Annotate
for row in df.itertuples():
    ax.text(row.Index, row.cty+.5, s=round(row.cty, 2), horizontalalignment='center', verticalalignment='bottom', fontsize=14)

plt.show()

18

【17】點圖(Dot Plot)

點圖可以表示項目的排名順序。由於它是沿水平軸對齊的,所以可以更容易地看到點之間的距離。

# Prepare Data
df_raw = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")
df = df_raw[['cty', 'manufacturer']].groupby('manufacturer').apply(lambda x: x.mean())
df.sort_values('cty', inplace=True)
df.reset_index(inplace=True)

# Draw plot
fig, ax = plt.subplots(figsize=(16, 10), dpi=80)
ax.hlines(y=df.index, xmin=11, xmax=26, color='gray', alpha=0.7, linewidth=1, linestyles='dashdot')
ax.scatter(y=df.index, x=df.cty, s=75, color='firebrick', alpha=0.7)

# Title, Label, Ticks and Ylim
ax.set_title('Dot Plot for Highway Mileage', fontdict={'size': 22})
ax.set_xlabel('Miles Per Gallon')
ax.set_yticks(df.index)
ax.set_yticklabels(df.manufacturer.str.title(), fontdict={'horizontalalignment': 'right'})
ax.set_xlim(10, 27)
plt.show()

19

【18】坡度圖(Slope Chart)

坡度圖最適合比較給定人員/項目的“前”和“後”位置。

import matplotlib.lines as mlines

# Import Data
df = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/gdppercap.csv")

left_label = [str(c) + ', ' + str(round(y)) for c, y in zip(df.continent, df['1952'])]
right_label = [str(c) + ', ' + str(round(y)) for c, y in zip(df.continent, df['1957'])]
klass = ['red' if (y1 - y2) < 0 else 'green' for y1, y2 in zip(df['1952'], df['1957'])]


# draw line
# https://stackoverflow.com/questions/36470343/how-to-draw-a-line-with-matplotlib/36479941
def newline(p1, p2, color='black'):
    ax = plt.gca()
    l = mlines.Line2D([p1[0], p2[0]], [p1[1], p2[1]], color='red' if p1[1] - p2[1] > 0 else 'green', marker='o',
                      markersize=6)
    ax.add_line(l)
    return l


fig, ax = plt.subplots(1, 1, figsize=(14, 14), dpi=80)

# Vertical Lines
ax.vlines(x=1, ymin=500, ymax=13000, color='black', alpha=0.7, linewidth=1, linestyles='dotted')
ax.vlines(x=3, ymin=500, ymax=13000, color='black', alpha=0.7, linewidth=1, linestyles='dotted')

# Points
ax.scatter(y=df['1952'], x=np.repeat(1, df.shape[0]), s=10, color='black', alpha=0.7)
ax.scatter(y=df['1957'], x=np.repeat(3, df.shape[0]), s=10, color='black', alpha=0.7)

# Line Segmentsand Annotation
for p1, p2, c in zip(df['1952'], df['1957'], df['continent']):
    newline([1, p1], [3, p2])
    ax.text(1 - 0.05, p1, c + ', ' + str(round(p1)), horizontalalignment='right', verticalalignment='center',
            fontdict={'size': 14})
    ax.text(3 + 0.05, p2, c + ', ' + str(round(p2)), horizontalalignment='left', verticalalignment='center',
            fontdict={'size': 14})

# 'Before' and 'After' Annotations
ax.text(1 - 0.05, 13000, 'BEFORE', horizontalalignment='right', verticalalignment='center',
        fontdict={'size': 18, 'weight': 700})
ax.text(3 + 0.05, 13000, 'AFTER', horizontalalignment='left', verticalalignment='center',
        fontdict={'size': 18, 'weight': 700})

# Decoration
ax.set_title("Slopechart: Comparing GDP Per Capita between 1952 vs 1957", fontdict={'size': 22})
ax.set(xlim=(0, 4), ylim=(0, 14000), ylabel='Mean GDP Per Capita')
ax.set_xticks([1, 3])
ax.set_xticklabels(["1952", "1957"])
plt.yticks(np.arange(500, 13000, 2000), fontsize=12)

# Lighten borders
plt.gca().spines["top"].set_alpha(.0)
plt.gca().spines["bottom"].set_alpha(.0)
plt.gca().spines["right"].set_alpha(.0)
plt.gca().spines["left"].set_alpha(.0)
plt.show()

20

【19】啞鈴圖(Dumbbell Plot)

啞鈴圖傳達了各種項目的“前”和“後”位置以及項目的等級順序。如果您希望可視化特定項目/計劃對不同對象的影響,那麼它非常有用。

import matplotlib.lines as mlines

# Import Data
df = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/health.csv")
df.sort_values('pct_2014', inplace=True)
df.reset_index(inplace=True)


# Func to draw line segment
def newline(p1, p2, color='black'):
    ax = plt.gca()
    l = mlines.Line2D([p1[0], p2[0]], [p1[1], p2[1]], color='skyblue')
    ax.add_line(l)
    return l


# Figure and Axes
fig, ax = plt.subplots(1, 1, figsize=(14, 14), facecolor='#f7f7f7', dpi=80)

# Vertical Lines
ax.vlines(x=.05, ymin=0, ymax=26, color='black', alpha=1, linewidth=1, linestyles='dotted')
ax.vlines(x=.10, ymin=0, ymax=26, color='black', alpha=1, linewidth=1, linestyles='dotted')
ax.vlines(x=.15, ymin=0, ymax=26, color='black', alpha=1, linewidth=1, linestyles='dotted')
ax.vlines(x=.20, ymin=0, ymax=26, color='black', alpha=1, linewidth=1, linestyles='dotted')

# Points
ax.scatter(y=df['index'], x=df['pct_2013'], s=50, color='#0e668b', alpha=0.7)
ax.scatter(y=df['index'], x=df['pct_2014'], s=50, color='#a3c4dc', alpha=0.7)

# Line Segments
for i, p1, p2 in zip(df['index'], df['pct_2013'], df['pct_2014']):
    newline([p1, i], [p2, i])

# Decoration
ax.set_facecolor('#f7f7f7')
ax.set_title("Dumbell Chart: Pct Change - 2013 vs 2014", fontdict={'size': 22})
ax.set(xlim=(0, .25), ylim=(-1, 27), ylabel='Mean GDP Per Capita')
ax.set_xticks([.05, .1, .15, .20])
ax.set_xticklabels(['5%', '15%', '20%', '25%'])
ax.set_xticklabels(['5%', '15%', '20%', '25%'])
plt.show()

21

【6x00】分佈(Distribution)

【20】連續變量的直方圖(Histogram for Continuous Variable)

連續變量的直方圖顯示給定變量的頻率分佈。下面的圖表基於分類變量對頻率條進行分組,從而更深入地瞭解連續變量和分類變量。

# Import Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Prepare data
x_var = 'displ'
groupby_var = 'class'
df_agg = df.loc[:, [x_var, groupby_var]].groupby(groupby_var)
vals = [df[x_var].values.tolist() for i, df in df_agg]

# Draw
plt.figure(figsize=(16, 9), dpi=80)
colors = [plt.cm.Spectral(i / float(len(vals) - 1)) for i in range(len(vals))]
n, bins, patches = plt.hist(vals, 30, stacked=True, density=False, color=colors[:len(vals)])

# Decoration
plt.legend({group: col for group, col in zip(np.unique(df[groupby_var]).tolist(), colors[:len(vals)])})
plt.title(f"Stacked Histogram of ${x_var}$ colored by ${groupby_var}$", fontsize=22)
plt.xlabel(x_var)
plt.ylabel("Frequency")
plt.ylim(0, 25)
plt.xticks(ticks=bins[::3], labels=[round(b, 1) for b in bins[::3]])
plt.show()

22

【21】分類變量的直方圖(Histogram for Categorical Variable)

分類變量的直方圖顯示該變量的頻率分佈。通過給條形圖上色,您可以將分佈與表示顏色的另一個類型變量相關聯。

# Import Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Prepare data
x_var = 'manufacturer'
groupby_var = 'class'
df_agg = df.loc[:, [x_var, groupby_var]].groupby(groupby_var)
vals = [df[x_var].values.tolist() for i, df in df_agg]

# Draw
plt.figure(figsize=(16, 9), dpi=80)
colors = [plt.cm.Spectral(i / float(len(vals) - 1)) for i in range(len(vals))]
n, bins, patches = plt.hist(vals, df[x_var].unique().__len__(), stacked=True, density=False, color=colors[:len(vals)])

# Decoration
plt.legend({group: col for group, col in zip(np.unique(df[groupby_var]).tolist(), colors[:len(vals)])})
plt.title(f"Stacked Histogram of ${x_var}$ colored by ${groupby_var}$", fontsize=22)
plt.xlabel(x_var)
plt.ylabel("Frequency")
plt.ylim(0, 40)
plt.xticks(ticks=bins, labels=np.unique(df[x_var]).tolist(), rotation=90, horizontalalignment='left')
plt.show()

23

【22】密度圖(Density Plot)

密度圖是連續變量分佈可視化的常用工具。通過按“response”變量對它們進行分組,您可以檢查 X 和 Y 之間的關係。如果出於代表性目的來描述城市裏程分佈如何隨氣缸數而變化,請參見下面的情況。

# Import Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Draw Plot
plt.figure(figsize=(16, 10), dpi=80)
sns.kdeplot(df.loc[df['cyl'] == 4, "cty"], shade=True, color="g", label="Cyl=4", alpha=.7)
sns.kdeplot(df.loc[df['cyl'] == 5, "cty"], shade=True, color="deeppink", label="Cyl=5", alpha=.7)
sns.kdeplot(df.loc[df['cyl'] == 6, "cty"], shade=True, color="dodgerblue", label="Cyl=6", alpha=.7)
sns.kdeplot(df.loc[df['cyl'] == 8, "cty"], shade=True, color="orange", label="Cyl=8", alpha=.7)

# Decoration
plt.title('Density Plot of City Mileage by n_Cylinders', fontsize=22)
plt.legend()
plt.show()

24

【23】直方圖密度曲線(Density Curves with Histogram)

具有直方圖的密度曲線將兩個圖所傳達的信息集合在一起,因此您可以將它們都放在一個圖形中,而不是放在兩個圖形中。

# Import Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Draw Plot
plt.figure(figsize=(13, 10), dpi=80)
sns.distplot(df.loc[df['class'] == 'compact', "cty"], color="dodgerblue", label="Compact", hist_kws={'alpha': .7},
             kde_kws={'linewidth': 3})
sns.distplot(df.loc[df['class'] == 'suv', "cty"], color="orange", label="SUV", hist_kws={'alpha': .7},
             kde_kws={'linewidth': 3})
sns.distplot(df.loc[df['class'] == 'minivan', "cty"], color="g", label="minivan", hist_kws={'alpha': .7},
             kde_kws={'linewidth': 3})
plt.ylim(0, 0.35)

# Decoration
plt.title('Density Plot of City Mileage by Vehicle Type', fontsize=22)
plt.legend()
plt.show()

25

【24】山峯疊巒圖 / 歡樂圖(Joy Plot)

Joy Plot 允許不同組的密度曲線重疊,這是一種很好的可視化方法,可以直觀地顯示大量分組之間的關係。它看起來賞心悅目,清楚地傳達了正確的信息。它可以使用基於 matplotlibjoypy 包輕鬆構建。

【譯者 TRHX 注:Joy Plot 看起來就像是山峯疊巒,山巒起伏,層次分明,但取名爲 Joy,歡樂的意思,所以不太好翻譯,在使用該方法時要先安裝 joypy 庫】

# !pip install joypy
# Import Data
import joypy
# 原文沒有 import joypy,譯者 TRHX 添加

mpg = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Draw Plot
plt.figure(figsize=(16, 10), dpi=80)
fig, axes = joypy.joyplot(mpg, column=['hwy', 'cty'], by="class", ylim='own', figsize=(14, 10))

# Decoration
plt.title('Joy Plot of City and Highway Mileage by Class', fontsize=22)
plt.show()

26

【25】分佈式點圖(Distributed Dot Plot)

分佈點圖顯示按組分割的點的單變量分佈。點越暗,數據點在該區域的集中程度就越高。通過對中值進行不同的着色,這些組的真實位置立即變得明顯。

import matplotlib.patches as mpatches

# Prepare Data
df_raw = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")
cyl_colors = {4: 'tab:red', 5: 'tab:green', 6: 'tab:blue', 8: 'tab:orange'}
df_raw['cyl_color'] = df_raw.cyl.map(cyl_colors)

# Mean and Median city mileage by make
df = df_raw[['cty', 'manufacturer']].groupby('manufacturer').apply(lambda x: x.mean())
df.sort_values('cty', ascending=False, inplace=True)
df.reset_index(inplace=True)
df_median = df_raw[['cty', 'manufacturer']].groupby('manufacturer').apply(lambda x: x.median())

# Draw horizontal lines
fig, ax = plt.subplots(figsize=(16, 10), dpi=80)
ax.hlines(y=df.index, xmin=0, xmax=40, color='gray', alpha=0.5, linewidth=.5, linestyles='dashdot')

# Draw the Dots
for i, make in enumerate(df.manufacturer):
    df_make = df_raw.loc[df_raw.manufacturer == make, :]
    ax.scatter(y=np.repeat(i, df_make.shape[0]), x='cty', data=df_make, s=75, edgecolors='gray', c='w', alpha=0.5)
    ax.scatter(y=i, x='cty', data=df_median.loc[df_median.index == make, :], s=75, c='firebrick')

# Annotate
ax.text(33, 13, "$red \; dots \; are \; the \: median$", fontdict={'size': 12}, color='firebrick')

# Decorations
red_patch = plt.plot([], [], marker="o", ms=10, ls="", mec=None, color='firebrick', label="Median")
plt.legend(handles=red_patch)
ax.set_title('Distribution of City Mileage by Make', fontdict={'size': 22})
ax.set_xlabel('Miles Per Gallon (City)', alpha=0.7)
ax.set_yticks(df.index)
ax.set_yticklabels(df.manufacturer.str.title(), fontdict={'horizontalalignment': 'right'}, alpha=0.7)
ax.set_xlim(1, 40)
plt.xticks(alpha=0.7)
plt.gca().spines["top"].set_visible(False)
plt.gca().spines["bottom"].set_visible(False)
plt.gca().spines["right"].set_visible(False)
plt.gca().spines["left"].set_visible(False)
plt.grid(axis='both', alpha=.4, linewidth=.1)
plt.show()

27

【26】箱形圖(Box Plot)

箱形圖是可視化分佈的一種好方法,同時牢記中位數,第 25 個第 75 個四分位數和離羣值。 但是,在解釋方框的大小時需要小心,這可能會扭曲該組中包含的點數。 因此,手動提供每個框中的觀察次數可以幫助克服此缺點。

例如,左側的前兩個框,儘管它們分別具有 5 和 47 個 obs,但是卻具有相同大小, 因此,有必要寫下該組中的觀察數。

# Import Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Draw Plot
plt.figure(figsize=(13, 10), dpi=80)
sns.boxplot(x='class', y='hwy', data=df, notch=False)


# Add N Obs inside boxplot (optional)
def add_n_obs(df, group_col, y):
    medians_dict = {grp[0]: grp[1][y].median() for grp in df.groupby(group_col)}
    xticklabels = [x.get_text() for x in plt.gca().get_xticklabels()]
    n_obs = df.groupby(group_col)[y].size().values
    for (x, xticklabel), n_ob in zip(enumerate(xticklabels), n_obs):
        plt.text(x, medians_dict[xticklabel] * 1.01, "#obs : " + str(n_ob), horizontalalignment='center',
                 fontdict={'size': 14}, color='white')


add_n_obs(df, group_col='class', y='hwy')

# Decoration
plt.title('Box Plot of Highway Mileage by Vehicle Class', fontsize=22)
plt.ylim(10, 40)
plt.show()

28

【27】點 + 箱形圖(Dot + Box Plot)

點 + 箱形圖傳達類似於分組的箱形圖信息。此外,這些點還提供了每組中有多少數據點的含義。

# Import Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Draw Plot
plt.figure(figsize=(13,10), dpi= 80)
sns.boxplot(x='class', y='hwy', data=df, hue='cyl')
sns.stripplot(x='class', y='hwy', data=df, color='black', size=3, jitter=1)

for i in range(len(df['class'].unique())-1):
    plt.vlines(i+.5, 10, 45, linestyles='solid', colors='gray', alpha=0.2)

# Decoration
plt.title('Box Plot of Highway Mileage by Vehicle Class', fontsize=22)
plt.legend(title='Cylinders')
plt.show()

29

【28】小提琴圖(Violin Plot)

小提琴圖是箱形圖在視覺上令人愉悅的替代品。 小提琴的形狀或面積取決於它所持有的觀察次數。 但是,小提琴圖可能更難以閱讀,並且在專業設置中不常用。

# Import Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Draw Plot
plt.figure(figsize=(13, 10), dpi=80)
sns.violinplot(x='class', y='hwy', data=df, scale='width', inner='quartile')

# Decoration
plt.title('Violin Plot of Highway Mileage by Vehicle Class', fontsize=22)
plt.show()

30

【29】人口金字塔圖(Population Pyramid)

人口金字塔可用於顯示按體積排序的組的分佈。或者它也可以用於顯示人口的逐級過濾,因爲它是用來顯示有多少人通過一個營銷漏斗(Marketing Funnel)的每個階段。

# Read data
df = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/email_campaign_funnel.csv")

# Draw Plot
plt.figure(figsize=(13, 10), dpi=80)
group_col = 'Gender'
order_of_bars = df.Stage.unique()[::-1]
colors = [plt.cm.Spectral(i / float(len(df[group_col].unique()) - 1)) for i in range(len(df[group_col].unique()))]

for c, group in zip(colors, df[group_col].unique()):
    sns.barplot(x='Users', y='Stage', data=df.loc[df[group_col] == group, :], order=order_of_bars, color=c, label=group)

# Decorations
plt.xlabel("$Users$")
plt.ylabel("Stage of Purchase")
plt.yticks(fontsize=12)
plt.title("Population Pyramid of the Marketing Funnel", fontsize=22)
plt.legend()
plt.show()

31

【30】分類圖(Categorical Plots)

seaborn 庫提供的分類圖可用於可視化彼此相關的兩個或更多分類變量的計數分佈。

# Load Dataset
titanic = sns.load_dataset("titanic")

# Plot
g = sns.catplot("alive", col="deck", col_wrap=4,
                data=titanic[titanic.deck.notnull()],
                kind="count", height=3.5, aspect=.8,
                palette='tab20')

# 譯者 TRHX 註釋掉了這一行代碼
# fig.suptitle('sf')
plt.show()

32

# Load Dataset
titanic = sns.load_dataset("titanic")

# Plot
sns.catplot(x="age", y="embark_town",
            hue="sex", col="class",
            data=titanic[titanic.embark_town.notnull()],
            orient="h", height=5, aspect=1, palette="tab10",
            kind="violin", dodge=True, cut=0, bw=.2)

# 譯者 TRHX 添加了這行代碼
plt.show()

33

【7x00】組成(Composition)

【31】華夫餅圖(Waffle Chart)

華夫餅圖可以使用 pywaffle 包創建,用於顯示較大羣體中的組的組成。

【譯者 TRHX 注:在使用該方法時要先安裝 pywaffle 庫】

# ! pip install pywaffle
# Reference: https://stackoverflow.com/questions/41400136/how-to-do-waffle-charts-in-python-square-piechart
from pywaffle import Waffle

# Import
df_raw = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Prepare Data
df = df_raw.groupby('class').size().reset_index(name='counts')
n_categories = df.shape[0]
colors = [plt.cm.inferno_r(i / float(n_categories)) for i in range(n_categories)]

# Draw Plot and Decorate
fig = plt.figure(
    FigureClass=Waffle,
    plots={
        '111': {
            'values': df['counts'],
            'labels': ["{0} ({1})".format(n[0], n[1]) for n in df[['class', 'counts']].itertuples()],
            'legend': {'loc': 'upper left', 'bbox_to_anchor': (1.05, 1), 'fontsize': 12},
            'title': {'label': '# Vehicles by Class', 'loc': 'center', 'fontsize': 18}
        },
    },
    rows=7,
    colors=colors,
    figsize=(16, 9)
)

# 譯者 TRHX 添加了這行代碼
plt.show()

34

# ! pip install pywaffle
from pywaffle import Waffle

# Import
# 譯者 TRHX 取消註釋了這行代碼
df_raw = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Prepare Data
# By Class Data
df_class = df_raw.groupby('class').size().reset_index(name='counts_class')
n_categories = df_class.shape[0]
colors_class = [plt.cm.Set3(i / float(n_categories)) for i in range(n_categories)]

# By Cylinders Data
df_cyl = df_raw.groupby('cyl').size().reset_index(name='counts_cyl')
n_categories = df_cyl.shape[0]
colors_cyl = [plt.cm.Spectral(i / float(n_categories)) for i in range(n_categories)]

# By Make Data
df_make = df_raw.groupby('manufacturer').size().reset_index(name='counts_make')
n_categories = df_make.shape[0]
colors_make = [plt.cm.tab20b(i / float(n_categories)) for i in range(n_categories)]

# Draw Plot and Decorate
fig = plt.figure(
    FigureClass=Waffle,
    plots={
        '311': {
            'values': df_class['counts_class'],
            'labels': ["{1}".format(n[0], n[1]) for n in df_class[['class', 'counts_class']].itertuples()],
            'legend': {'loc': 'upper left', 'bbox_to_anchor': (1.05, 1), 'fontsize': 12, 'title': 'Class'},
            'title': {'label': '# Vehicles by Class', 'loc': 'center', 'fontsize': 18},
            'colors': colors_class
        },
        '312': {
            'values': df_cyl['counts_cyl'],
            'labels': ["{1}".format(n[0], n[1]) for n in df_cyl[['cyl', 'counts_cyl']].itertuples()],
            'legend': {'loc': 'upper left', 'bbox_to_anchor': (1.05, 1), 'fontsize': 12, 'title': 'Cyl'},
            'title': {'label': '# Vehicles by Cyl', 'loc': 'center', 'fontsize': 18},
            'colors': colors_cyl
        },
        '313': {
            'values': df_make['counts_make'],
            'labels': ["{1}".format(n[0], n[1]) for n in df_make[['manufacturer', 'counts_make']].itertuples()],
            'legend': {'loc': 'upper left', 'bbox_to_anchor': (1.05, 1), 'fontsize': 12, 'title': 'Manufacturer'},
            'title': {'label': '# Vehicles by Make', 'loc': 'center', 'fontsize': 18},
            'colors': colors_make
        }
    },
    rows=9,
    figsize=(16, 14)
)

# 譯者 TRHX 添加了這行代碼
plt.show()

35

【32】餅圖(Pie Chart)

餅圖是顯示組成的經典方法。然而,現在一般不宜使用,因爲餡餅部分的面積有時會產生誤導。因此,如果要使用餅圖,強烈建議您顯式地記下餅圖每個部分的百分比或數字。

# Import
df_raw = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Prepare Data
df = df_raw.groupby('class').size()

# Make the plot with pandas
'''
原代碼:df.plot(kind='pie', subplots=True, figsize=(8, 8), dpi=80)
譯者 TRHX 刪除了 dpi= 80
'''
df.plot(kind='pie', subplots=True, figsize=(8, 8))
plt.title("Pie Chart of Vehicle Class - Bad")
plt.ylabel("")
plt.show()

36

# Import
df_raw = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Prepare Data
df = df_raw.groupby('class').size().reset_index(name='counts')

# Draw Plot
fig, ax = plt.subplots(figsize=(12, 7), subplot_kw=dict(aspect="equal"), dpi=80)

data = df['counts']
categories = df['class']
explode = [0, 0, 0, 0, 0, 0.1, 0]


def func(pct, allvals):
    absolute = int(pct / 100. * np.sum(allvals))
    return "{:.1f}% ({:d} )".format(pct, absolute)


wedges, texts, autotexts = ax.pie(data,
                                  autopct=lambda pct: func(pct, data),
                                  textprops=dict(color="w"),
                                  colors=plt.cm.Dark2.colors,
                                  startangle=140,
                                  explode=explode)

# Decoration
ax.legend(wedges, categories, title="Vehicle Class", loc="center left", bbox_to_anchor=(1, 0, 0.5, 1))
plt.setp(autotexts, size=10, weight=700)
ax.set_title("Class of Vehicles: Pie Chart")
plt.show()

37

【33】矩陣樹形圖(Treemap)

矩陣樹形圖類似於餅圖,它可以更好地完成工作而不會誤導每個組的貢獻。

【譯者 TRHX 注:在使用該方法時要先安裝 squarify 庫】

# pip install squarify
import squarify

# Import Data
df_raw = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Prepare Data
df = df_raw.groupby('class').size().reset_index(name='counts')
labels = df.apply(lambda x: str(x[0]) + "\n (" + str(x[1]) + ")", axis=1)
sizes = df['counts'].values.tolist()
colors = [plt.cm.Spectral(i / float(len(labels))) for i in range(len(labels))]

# Draw Plot
plt.figure(figsize=(12, 8), dpi=80)
squarify.plot(sizes=sizes, label=labels, color=colors, alpha=.8)

# Decorate
plt.title('Treemap of Vechile Class')
plt.axis('off')
plt.show()

38

【34】條形圖(Bar Chart)

條形圖是一種基於計數或任何給定度量的可視化項的經典方法。在下面的圖表中,我爲每個項目使用了不同的顏色,但您通常可能希望爲所有項目選擇一種顏色,除非您按組對它們進行着色。顏色名稱存儲在下面代碼中的 all_colors 中。您可以通過在 plt.plot() 中設置 color 參數來更改條形的顏色。

import random

# Import Data
df_raw = pd.read_csv("https://github.com/selva86/datasets/raw/master/mpg_ggplot2.csv")

# Prepare Data
df = df_raw.groupby('manufacturer').size().reset_index(name='counts')
n = df['manufacturer'].unique().__len__()+1
all_colors = list(plt.cm.colors.cnames.keys())
random.seed(100)
c = random.choices(all_colors, k=n)

# Plot Bars
plt.figure(figsize=(16,10), dpi= 80)
plt.bar(df['manufacturer'], df['counts'], color=c, width=.5)
for i, val in enumerate(df['counts'].values):
    plt.text(i, val, float(val), horizontalalignment='center', verticalalignment='bottom', fontdict={'fontweight':500, 'size':12})

# Decoration
plt.gca().set_xticklabels(df['manufacturer'], rotation=60, horizontalalignment= 'right')
plt.title("Number of Vehicles by Manaufacturers", fontsize=22)
plt.ylabel('# Vehicles')
plt.ylim(0, 45)
plt.show()

39

【8x00】變化(Change)

【35】時間序列圖(Time Series Plot)

時間序列圖用於可視化給定指標隨時間的變化。在這裏你可以看到 1949 年到 1969 年間的航空客運量是如何變化的。

# Import Data
df = pd.read_csv('https://github.com/selva86/datasets/raw/master/AirPassengers.csv')

# Draw Plot
plt.figure(figsize=(16, 10), dpi=80)
plt.plot('date', 'traffic', data=df, color='tab:red')

# Decoration
plt.ylim(50, 750)
xtick_location = df.index.tolist()[::12]
xtick_labels = [x[-4:] for x in df.date.tolist()[::12]]
plt.xticks(ticks=xtick_location, labels=xtick_labels, rotation=0, fontsize=12, horizontalalignment='center', alpha=.7)
plt.yticks(fontsize=12, alpha=.7)
plt.title("Air Passengers Traffic (1949 - 1969)", fontsize=22)
plt.grid(axis='both', alpha=.3)

# Remove borders
plt.gca().spines["top"].set_alpha(0.0)
plt.gca().spines["bottom"].set_alpha(0.3)
plt.gca().spines["right"].set_alpha(0.0)
plt.gca().spines["left"].set_alpha(0.3)
plt.show()

40

【36】帶波峯和波谷註釋的時間序列圖(Time Series with Peaks and Troughs Annotated)

下面的時間序列繪製了所有的波峯和波谷,並註釋了所選特殊事件的發生。

# Import Data
df = pd.read_csv('https://github.com/selva86/datasets/raw/master/AirPassengers.csv')

# Get the Peaks and Troughs
data = df['traffic'].values
doublediff = np.diff(np.sign(np.diff(data)))
peak_locations = np.where(doublediff == -2)[0] + 1

doublediff2 = np.diff(np.sign(np.diff(-1 * data)))
trough_locations = np.where(doublediff2 == -2)[0] + 1

# Draw Plot
plt.figure(figsize=(16, 10), dpi=80)
plt.plot('date', 'traffic', data=df, color='tab:blue', label='Air Traffic')
plt.scatter(df.date[peak_locations], df.traffic[peak_locations], marker=mpl.markers.CARETUPBASE, color='tab:green',
            s=100, label='Peaks')
plt.scatter(df.date[trough_locations], df.traffic[trough_locations], marker=mpl.markers.CARETDOWNBASE, color='tab:red',
            s=100, label='Troughs')

# Annotate
for t, p in zip(trough_locations[1::5], peak_locations[::3]):
    plt.text(df.date[p], df.traffic[p] + 15, df.date[p], horizontalalignment='center', color='darkgreen')
    plt.text(df.date[t], df.traffic[t] - 35, df.date[t], horizontalalignment='center', color='darkred')

# Decoration
plt.ylim(50, 750)
xtick_location = df.index.tolist()[::6]
xtick_labels = df.date.tolist()[::6]
plt.xticks(ticks=xtick_location, labels=xtick_labels, rotation=90, fontsize=12, alpha=.7)
plt.title("Peak and Troughs of Air Passengers Traffic (1949 - 1969)", fontsize=22)
plt.yticks(fontsize=12, alpha=.7)

# Lighten borders
plt.gca().spines["top"].set_alpha(.0)
plt.gca().spines["bottom"].set_alpha(.3)
plt.gca().spines["right"].set_alpha(.0)
plt.gca().spines["left"].set_alpha(.3)

plt.legend(loc='upper left')
plt.grid(axis='y', alpha=.3)
plt.show()

41

【37】自相關 (ACF) 和部分自相關 (PACF) 圖(Autocorrelation (ACF) and Partial Autocorrelation (PACF) Plot)

自相關圖(ACF圖)顯示了時間序列與其自身滯後的相關性。 每條垂直線(在自相關圖上)表示系列與滯後 0 之間的滯後的相關性。圖中的藍色陰影區域是顯著性級別。 那些位於藍線之上的滯後是顯著的滯後。

那麼如何解釋呢?

對於航空乘客來說,我們看到超過 14 個滯後已經越過藍線,因此意義重大。這意味着,14 年前的航空客運量對今天的交通量產生了影響。

另一方面,部分自相關圖(PACF)顯示了任何給定滯後(時間序列)相對於當前序列的自相關,但消除了中間滯後的貢獻。

from statsmodels.graphics.tsaplots import plot_acf, plot_pacf

# Import Data
df = pd.read_csv('https://github.com/selva86/datasets/raw/master/AirPassengers.csv')

# Draw Plot
fig, (ax1, ax2) = plt.subplots(1, 2, figsize=(16, 6), dpi=80)
plot_acf(df.traffic.tolist(), ax=ax1, lags=50)
plot_pacf(df.traffic.tolist(), ax=ax2, lags=20)

# Decorate
# lighten the borders
ax1.spines["top"].set_alpha(.3); ax2.spines["top"].set_alpha(.3)
ax1.spines["bottom"].set_alpha(.3); ax2.spines["bottom"].set_alpha(.3)
ax1.spines["right"].set_alpha(.3); ax2.spines["right"].set_alpha(.3)
ax1.spines["left"].set_alpha(.3); ax2.spines["left"].set_alpha(.3)

# font size of tick labels
ax1.tick_params(axis='both', labelsize=12)
ax2.tick_params(axis='both', labelsize=12)
plt.show()

42

【38】交叉相關圖(Cross Correlation plot)

交叉相關圖顯示了兩個時間序列相互之間的滯後。

import statsmodels.tsa.stattools as stattools

# Import Data
df = pd.read_csv('https://github.com/selva86/datasets/raw/master/mortality.csv')
x = df['mdeaths']
y = df['fdeaths']

# Compute Cross Correlations
ccs = stattools.ccf(x, y)[:100]
nlags = len(ccs)

# Compute the Significance level
# ref: https://stats.stackexchange.com/questions/3115/cross-correlation-significance-in-r/3128#3128
conf_level = 2 / np.sqrt(nlags)

# Draw Plot
plt.figure(figsize=(12, 7), dpi=80)

plt.hlines(0, xmin=0, xmax=100, color='gray')  # 0 axis
plt.hlines(conf_level, xmin=0, xmax=100, color='gray')
plt.hlines(-conf_level, xmin=0, xmax=100, color='gray')

plt.bar(x=np.arange(len(ccs)), height=ccs, width=.3)

# Decoration
plt.title('$Cross\; Correlation\; Plot:\; mdeaths\; vs\; fdeaths$', fontsize=22)
plt.xlim(0, len(ccs))
plt.show()

43

【39】時間序列分解圖(Time Series Decomposition Plot)

時間序列分解圖將時間序列分解爲趨勢、季節和殘差分量。

from statsmodels.tsa.seasonal import seasonal_decompose
from dateutil.parser import parse

# Import Data
df = pd.read_csv('https://github.com/selva86/datasets/raw/master/AirPassengers.csv')
dates = pd.DatetimeIndex([parse(d).strftime('%Y-%m-01') for d in df['date']])
df.set_index(dates, inplace=True)

# Decompose
result = seasonal_decompose(df['traffic'], model='multiplicative')

# Plot
plt.rcParams.update({'figure.figsize': (10, 10)})
result.plot().suptitle('Time Series Decomposition of Air Passengers')
plt.show()

44

【40】多重時間序列(Multiple Time Series)

您可以在同一圖表上繪製多個測量相同值的時間序列,如下所示。

# Import Data
df = pd.read_csv('https://github.com/selva86/datasets/raw/master/mortality.csv')

# Define the upper limit, lower limit, interval of Y axis and colors
y_LL = 100
y_UL = int(df.iloc[:, 1:].max().max() * 1.1)
y_interval = 400
mycolors = ['tab:red', 'tab:blue', 'tab:green', 'tab:orange']

# Draw Plot and Annotate
fig, ax = plt.subplots(1, 1, figsize=(16, 9), dpi=80)

columns = df.columns[1:]
for i, column in enumerate(columns):
    plt.plot(df.date.values, df[column].values, lw=1.5, color=mycolors[i])
    plt.text(df.shape[0] + 1, df[column].values[-1], column, fontsize=14, color=mycolors[i])

# Draw Tick lines
for y in range(y_LL, y_UL, y_interval):
    plt.hlines(y, xmin=0, xmax=71, colors='black', alpha=0.3, linestyles="--", lw=0.5)

# Decorations
plt.tick_params(axis="both", which="both", bottom=False, top=False,
                labelbottom=True, left=False, right=False, labelleft=True)

# Lighten borders
plt.gca().spines["top"].set_alpha(.3)
plt.gca().spines["bottom"].set_alpha(.3)
plt.gca().spines["right"].set_alpha(.3)
plt.gca().spines["left"].set_alpha(.3)

plt.title('Number of Deaths from Lung Diseases in the UK (1974-1979)', fontsize=22)
plt.yticks(range(y_LL, y_UL, y_interval), [str(y) for y in range(y_LL, y_UL, y_interval)], fontsize=12)
plt.xticks(range(0, df.shape[0], 12), df.date.values[::12], horizontalalignment='left', fontsize=12)
plt.ylim(y_LL, y_UL)
plt.xlim(-2, 80)
plt.show()

45

【41】使用次要的 Y 軸來繪製不同範圍的圖形(Plotting with different scales using secondary Y axis)

如果要顯示在同一時間點測量兩個不同數量的兩個時間序列,則可以在右側的次要 Y 軸上再繪製第二個系列。

# Import Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/economics.csv")

x = df['date']
y1 = df['psavert']
y2 = df['unemploy']

# Plot Line1 (Left Y Axis)
fig, ax1 = plt.subplots(1, 1, figsize=(16, 9), dpi=80)
ax1.plot(x, y1, color='tab:red')

# Plot Line2 (Right Y Axis)
ax2 = ax1.twinx()  # instantiate a second axes that shares the same x-axis
ax2.plot(x, y2, color='tab:blue')

# Decorations
# ax1 (left Y axis)
ax1.set_xlabel('Year', fontsize=20)
ax1.tick_params(axis='x', rotation=0, labelsize=12)
ax1.set_ylabel('Personal Savings Rate', color='tab:red', fontsize=20)
ax1.tick_params(axis='y', rotation=0, labelcolor='tab:red')
ax1.grid(alpha=.4)

# ax2 (right Y axis)
ax2.set_ylabel("# Unemployed (1000's)", color='tab:blue', fontsize=20)
ax2.tick_params(axis='y', labelcolor='tab:blue')
ax2.set_xticks(np.arange(0, len(x), 60))
ax2.set_xticklabels(x[::60], rotation=90, fontdict={'fontsize': 10})
ax2.set_title("Personal Savings Rate vs Unemployed: Plotting in Secondary Y Axis", fontsize=22)
fig.tight_layout()
plt.show()

46

【42】帶誤差帶的時間序列(Time Series with Error Bands)

如果您有一個時間序列數據集,其中每個時間點(日期/時間戳)有多個觀測值,則可以構造具有誤差帶的時間序列。下面您可以看到一些基於一天中不同時間的訂單的示例。還有一個關於45天內到達的訂單數量的例子。

在這種方法中,訂單數量的平均值用白線表示。並計算95%的置信區間,並圍繞平均值繪製。

from scipy.stats import sem

# Import Data
df = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/user_orders_hourofday.csv")
df_mean = df.groupby('order_hour_of_day').quantity.mean()
df_se = df.groupby('order_hour_of_day').quantity.apply(sem).mul(1.96)

# Plot
plt.figure(figsize=(16, 10), dpi=80)
plt.ylabel("# Orders", fontsize=16)
x = df_mean.index
plt.plot(x, df_mean, color="white", lw=2)
plt.fill_between(x, df_mean - df_se, df_mean + df_se, color="#3F5D7D")

# Decorations
# Lighten borders
plt.gca().spines["top"].set_alpha(0)
plt.gca().spines["bottom"].set_alpha(1)
plt.gca().spines["right"].set_alpha(0)
plt.gca().spines["left"].set_alpha(1)
plt.xticks(x[::2], [str(d) for d in x[::2]], fontsize=12)
plt.title("User Orders by Hour of Day (95% confidence)", fontsize=22)
plt.xlabel("Hour of Day")

s, e = plt.gca().get_xlim()
plt.xlim(s, e)

# Draw Horizontal Tick lines
for y in range(8, 20, 2):
    plt.hlines(y, xmin=s, xmax=e, colors='black', alpha=0.5, linestyles="--", lw=0.5)

plt.show()

47

"Data Source: https://www.kaggle.com/olistbr/brazilian-ecommerce#olist_orders_dataset.csv"
from dateutil.parser import parse
from scipy.stats import sem

# Import Data
df_raw = pd.read_csv('https://raw.githubusercontent.com/selva86/datasets/master/orders_45d.csv',
                     parse_dates=['purchase_time', 'purchase_date'])

# Prepare Data: Daily Mean and SE Bands
df_mean = df_raw.groupby('purchase_date').quantity.mean()
df_se = df_raw.groupby('purchase_date').quantity.apply(sem).mul(1.96)

# Plot
plt.figure(figsize=(16, 10), dpi=80)
plt.ylabel("# Daily Orders", fontsize=16)
x = [d.date().strftime('%Y-%m-%d') for d in df_mean.index]
plt.plot(x, df_mean, color="white", lw=2)
plt.fill_between(x, df_mean - df_se, df_mean + df_se, color="#3F5D7D")

# Decorations
# Lighten borders
plt.gca().spines["top"].set_alpha(0)
plt.gca().spines["bottom"].set_alpha(1)
plt.gca().spines["right"].set_alpha(0)
plt.gca().spines["left"].set_alpha(1)
plt.xticks(x[::6], [str(d) for d in x[::6]], fontsize=12)
plt.title("Daily Order Quantity of Brazilian Retail with Error Bands (95% confidence)", fontsize=20)

# Axis limits
s, e = plt.gca().get_xlim()
plt.xlim(s, e - 2)
plt.ylim(4, 10)

# Draw Horizontal Tick lines
for y in range(5, 10, 1):
    plt.hlines(y, xmin=s, xmax=e, colors='black', alpha=0.5, linestyles="--", lw=0.5)

plt.show()

48

【43】堆積面積圖(Stacked Area Chart)

堆積面積圖提供了多個時間序列的貢獻程度的可視化表示,以便相互比較。

# Import Data
df = pd.read_csv('https://raw.githubusercontent.com/selva86/datasets/master/nightvisitors.csv')

# Decide Colors
mycolors = ['tab:red', 'tab:blue', 'tab:green', 'tab:orange', 'tab:brown', 'tab:grey', 'tab:pink', 'tab:olive']

# Draw Plot and Annotate
fig, ax = plt.subplots(1, 1, figsize=(16, 9), dpi=80)
columns = df.columns[1:]
labs = columns.values.tolist()

# Prepare data
x = df['yearmon'].values.tolist()
y0 = df[columns[0]].values.tolist()
y1 = df[columns[1]].values.tolist()
y2 = df[columns[2]].values.tolist()
y3 = df[columns[3]].values.tolist()
y4 = df[columns[4]].values.tolist()
y5 = df[columns[5]].values.tolist()
y6 = df[columns[6]].values.tolist()
y7 = df[columns[7]].values.tolist()
y = np.vstack([y0, y2, y4, y6, y7, y5, y1, y3])

# Plot for each column
labs = columns.values.tolist()
ax = plt.gca()
ax.stackplot(x, y, labels=labs, colors=mycolors, alpha=0.8)

# Decorations
ax.set_title('Night Visitors in Australian Regions', fontsize=18)
ax.set(ylim=[0, 100000])
ax.legend(fontsize=10, ncol=4)
plt.xticks(x[::5], fontsize=10, horizontalalignment='center')
plt.yticks(np.arange(10000, 100000, 20000), fontsize=10)
plt.xlim(x[0], x[-1])

# Lighten borders
plt.gca().spines["top"].set_alpha(0)
plt.gca().spines["bottom"].set_alpha(.3)
plt.gca().spines["right"].set_alpha(0)
plt.gca().spines["left"].set_alpha(.3)

plt.show()

49

【44】未堆積面積圖(Area Chart UnStacked)

未堆積的面積圖用於可視化兩個或多個序列彼此之間的進度(起伏)。在下面的圖表中,你可以清楚地看到,隨着失業持續時間的中位數增加,個人儲蓄率是如何下降的。未堆積面積圖很好地展示了這一現象。

# Import Data
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/economics.csv")

# Prepare Data
x = df['date'].values.tolist()
y1 = df['psavert'].values.tolist()
y2 = df['uempmed'].values.tolist()
mycolors = ['tab:red', 'tab:blue', 'tab:green', 'tab:orange', 'tab:brown', 'tab:grey', 'tab:pink', 'tab:olive']
columns = ['psavert', 'uempmed']

# Draw Plot
fig, ax = plt.subplots(1, 1, figsize=(16, 9), dpi=80)
ax.fill_between(x, y1=y1, y2=0, label=columns[1], alpha=0.5, color=mycolors[1], linewidth=2)
ax.fill_between(x, y1=y2, y2=0, label=columns[0], alpha=0.5, color=mycolors[0], linewidth=2)

# Decorations
ax.set_title('Personal Savings Rate vs Median Duration of Unemployment', fontsize=18)
ax.set(ylim=[0, 30])
ax.legend(loc='best', fontsize=12)
plt.xticks(x[::50], fontsize=10, horizontalalignment='center')
plt.yticks(np.arange(2.5, 30.0, 2.5), fontsize=10)
plt.xlim(-10, x[-1])

# Draw Tick lines
for y in np.arange(2.5, 30.0, 2.5):
    plt.hlines(y, xmin=0, xmax=len(x), colors='black', alpha=0.3, linestyles="--", lw=0.5)

# Lighten borders
plt.gca().spines["top"].set_alpha(0)
plt.gca().spines["bottom"].set_alpha(.3)
plt.gca().spines["right"].set_alpha(0)
plt.gca().spines["left"].set_alpha(.3)
plt.show()

50

【45】日曆熱力圖(Calendar Heat Map)

與時間序列相比,日曆地圖是另一種基於時間的數據可視化的不太受歡迎的方法。雖然在視覺上很吸引人,但數值並不十分明顯。然而,它能很好地描繪極端值和假日效果。

【譯者 TRHX 注:在使用該方法時要先安裝 calmap 庫】

import matplotlib as mpl
import calmap

# Import Data
df = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/yahoo.csv", parse_dates=['date'])
df.set_index('date', inplace=True)

# Plot
plt.figure(figsize=(16, 10), dpi=80)
calmap.calendarplot(df['2014']['VIX.Close'], fig_kws={'figsize': (16, 10)},
                    yearlabel_kws={'color': 'black', 'fontsize': 14}, subplot_kws={'title': 'Yahoo Stock Prices'})
plt.show()

51

【46】季節圖(Seasonal Plot)

季節圖可用於比較上一季度同一天(年/月/周等)時間序列的表現。

from dateutil.parser import parse

# Import Data
df = pd.read_csv('https://github.com/selva86/datasets/raw/master/AirPassengers.csv')

# Prepare data
df['year'] = [parse(d).year for d in df.date]
df['month'] = [parse(d).strftime('%b') for d in df.date]
years = df['year'].unique()

# 譯者 TRHX 添加了該行代碼
df.rename(columns={'value': 'traffic'}, inplace=True)

# Draw Plot
mycolors = ['tab:red', 'tab:blue', 'tab:green', 'tab:orange', 'tab:brown', 'tab:grey', 'tab:pink', 'tab:olive',
            'deeppink', 'steelblue', 'firebrick', 'mediumseagreen']
plt.figure(figsize=(16, 10), dpi=80)

for i, y in enumerate(years):
    plt.plot('month', 'traffic', data=df.loc[df.year == y, :], color=mycolors[i], label=y)
    plt.text(df.loc[df.year == y, :].shape[0] - .9, df.loc[df.year == y, 'traffic'][-1:].values[0], y, fontsize=12,
             color=mycolors[i])

# Decoration
plt.ylim(50, 750)
plt.xlim(-0.3, 11)
plt.ylabel('$Air Traffic$')
plt.yticks(fontsize=12, alpha=.7)
plt.title("Monthly Seasonal Plot: Air Passengers Traffic (1949 - 1969)", fontsize=22)
plt.grid(axis='y', alpha=.3)

# Remove borders
plt.gca().spines["top"].set_alpha(0.0)
plt.gca().spines["bottom"].set_alpha(0.5)
plt.gca().spines["right"].set_alpha(0.0)
plt.gca().spines["left"].set_alpha(0.5)
# plt.legend(loc='upper right', ncol=2, fontsize=12)
plt.show()

52

【9x00】分組( Groups)

【47】樹狀圖(Dendrogram)

樹狀圖根據給定的距離度量將相似的點組合在一起,並根據點的相似性將它們組織成樹狀鏈接。

import scipy.cluster.hierarchy as shc

# Import Data
df = pd.read_csv('https://raw.githubusercontent.com/selva86/datasets/master/USArrests.csv')

# Plot
plt.figure(figsize=(16, 10), dpi=80)
plt.title("USArrests Dendograms", fontsize=22)
dend = shc.dendrogram(shc.linkage(df[['Murder', 'Assault', 'UrbanPop', 'Rape']], method='ward'), labels=df.State.values,
                      color_threshold=100)
plt.xticks(fontsize=12)
plt.show()

53

【48】聚類圖(Cluster Plot)

聚類圖可以用來劃分屬於同一個聚類的點。下面是一個基於 USArrests 數據集將美國各州分成 5 組的代表性示例。這個聚類圖使用 ‘murder’ 和 ‘assault’ 作爲 X 軸和 Y 軸。或者,您可以將第一個主元件用作 X 軸和 Y 軸。

【譯者 TRHX 注:在使用該方法時要先安裝 sklearn 庫】

from sklearn.cluster import AgglomerativeClustering
from scipy.spatial import ConvexHull

# Import Data
df = pd.read_csv('https://raw.githubusercontent.com/selva86/datasets/master/USArrests.csv')

# Agglomerative Clustering
cluster = AgglomerativeClustering(n_clusters=5, affinity='euclidean', linkage='ward')
cluster.fit_predict(df[['Murder', 'Assault', 'UrbanPop', 'Rape']])

# Plot
plt.figure(figsize=(14, 10), dpi=80)
plt.scatter(df.iloc[:, 0], df.iloc[:, 1], c=cluster.labels_, cmap='tab10')


# Encircle
def encircle(x, y, ax=None, **kw):
    if not ax: ax = plt.gca()
    p = np.c_[x, y]
    hull = ConvexHull(p)
    poly = plt.Polygon(p[hull.vertices,:], **kw)
    ax.add_patch(poly)

# Draw polygon surrounding vertices
encircle(df.loc[cluster.labels_ == 0, 'Murder'], df.loc[cluster.labels_ == 0, 'Assault'], ec="k", fc="gold", alpha=0.2, linewidth=0)
encircle(df.loc[cluster.labels_ == 1, 'Murder'], df.loc[cluster.labels_ == 1, 'Assault'], ec="k", fc="tab:blue", alpha=0.2, linewidth=0)
encircle(df.loc[cluster.labels_ == 2, 'Murder'], df.loc[cluster.labels_ == 2, 'Assault'], ec="k", fc="tab:red", alpha=0.2, linewidth=0)
encircle(df.loc[cluster.labels_ == 3, 'Murder'], df.loc[cluster.labels_ == 3, 'Assault'], ec="k", fc="tab:green", alpha=0.2, linewidth=0)
encircle(df.loc[cluster.labels_ == 4, 'Murder'], df.loc[cluster.labels_ == 4, 'Assault'], ec="k", fc="tab:orange", alpha=0.2, linewidth=0)

# Decorations
plt.xlabel('Murder'); plt.xticks(fontsize=12)
plt.ylabel('Assault'); plt.yticks(fontsize=12)
plt.title('Agglomerative Clustering of USArrests (5 Groups)', fontsize=22)
plt.show()

54

【49】安德魯斯曲線(Andrews Curve)

安德魯斯曲線有助於可視化是否存在基於給定分組的數值特徵的固有分組。如果特徵(數據集中的列)不能幫助區分組(cyl),則行將不會像下圖所示被很好地分隔開。

from pandas.plotting import andrews_curves

# Import
df = pd.read_csv("https://github.com/selva86/datasets/raw/master/mtcars.csv")
df.drop(['cars', 'carname'], axis=1, inplace=True)

# Plot
plt.figure(figsize=(12, 9), dpi=80)
andrews_curves(df, 'cyl', colormap='Set1')

# Lighten borders
plt.gca().spines["top"].set_alpha(0)
plt.gca().spines["bottom"].set_alpha(.3)
plt.gca().spines["right"].set_alpha(0)
plt.gca().spines["left"].set_alpha(.3)

plt.title('Andrews Curves of mtcars', fontsize=22)
plt.xlim(-3, 3)
plt.grid(alpha=0.3)
plt.xticks(fontsize=12)
plt.yticks(fontsize=12)
plt.show()

55

【50】平行座標圖(Parallel Coordinates)

平行座標有助於可視化功能是否有助於有效地隔離組。如果一個分離受到影響,則該特徵可能在預測該組時非常有用。

from pandas.plotting import parallel_coordinates

# Import Data
df_final = pd.read_csv("https://raw.githubusercontent.com/selva86/datasets/master/diamonds_filter.csv")

# Plot
plt.figure(figsize=(12, 9), dpi=80)
parallel_coordinates(df_final, 'cut', colormap='Dark2')

# Lighten borders
plt.gca().spines["top"].set_alpha(0)
plt.gca().spines["bottom"].set_alpha(.3)
plt.gca().spines["right"].set_alpha(0)
plt.gca().spines["left"].set_alpha(.3)

plt.title('Parallel Coordinated of Diamonds', fontsize=22)
plt.grid(alpha=0.3)
plt.xticks(fontsize=12)
plt.yticks(fontsize=12)
plt.show()

56


這裏是一段防爬蟲文本,請讀者忽略。
本譯文首發於 CSDN,作者 Selva Prabhakaran,譯者 TRHX。
本文鏈接:https://itrhx.blog.csdn.net/article/details/106558131
原文鏈接:https://www.machinelearningplus.com/plots/top-50-matplotlib-visualizations-the-master-plots-python/

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