Table of Contents

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1 官方Demo

2 將實際數據應用於官方Demo

3 一些改善措施

3.1 重新設置字體大小

3.2 設置顯示顏色，Method 1：

3.3 設置顯示顏色， Method 2：

3.4 設置圖例（legend）

3.5 重新設置圖例（legend）

3.6 將某些類別突出顯示

前言

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matplotlib， 官方提供的餅圖Demo，功能比較比較簡單，在實際應用過程中，往往會有許多個性化的繪製需求，在這裡跟大家一起了解下餅圖（pie chart）的一些特色的功能的實現。

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from matplotlib import font_manager as fmnimport matplotlib as mplnimport pandas as pdnimport numpy as npnimport matplotlib.pyplot as pltn% matplotlib inlinenplt.style.use(ggplot)n

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1. 官方Demo

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import matplotlib.pyplot as pltnn# Pie chart, where the slices will be ordered and plotted counter-clockwise:nlabels = Frogs, Hogs, Dogs, Logsnsizes = [15, 30, 45, 10]nexplode = (0, 0.1, 0, 0) # only "explode" the 2nd slice (i.e. Hogs)nnfig1, ax1 = plt.subplots()nax1.pie(sizes, explode=explode, labels=labels, autopct=%1.1f%%,n shadow=True, startangle=90)nax1.axis(equal) # Equal aspect ratio ensures that pie is drawn as a circle.nnplt.savefig(Demo_official.jpg)nplt.show()n

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2. 將實際數據應用於官方Demo

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# 原始數據nshapes = [Cross, Cone, Egg, Teardrop, Chevron, Diamond, Cylinder,n Rectangle, Flash, Cigar, Changing, Formation, Oval, Disk,n Sphere, Fireball, Triangle, Circle, Light]nvalues = [ 287, 383, 842, 866, 1187, 1405, 1495, 1620, 1717,n 2313, 2378, 3070, 4332, 5841, 6482, 7785, 9358, 9818, 20254]nns = pd.Series(values, index=shapes)nsn

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from matplotlib import font_manager as fmnimport matplotlib as mplnn# Pie chart, where the slices will be ordered and plotted counter-clockwise:nlabels = s.indexnsizes = s.valuesnexplode = (0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0) # only "explode" the 1st slicennfig1, ax1 = plt.subplots()npatches, texts, autotexts = ax1.pie(sizes, explode=explode, labels=labels, autopct=%1.0f%%,n shadow=False, startangle=170)nax1.axis(equal) # Equal aspect ratio ensures that pie is drawn as a circle.nnplt.savefig(Demo_project.jpg)nplt.show()n

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上圖的一些問題：

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1. 顏色比較生硬

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2. 部分文字擁擠在一起，繪圖顯示不齊整

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3. 一些改善措施

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• 重新設置字體大小

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• 設置自選顏色

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• 設置圖例

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• 將某些類別突出顯示

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3.1 重新設置字體大小

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from matplotlib import font_manager as fmnimport matplotlib as mplnnlabels = s.indexnsizes = s.valuesnexplode = (0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0) # only "explode" the 1st slicennfig1, ax1 = plt.subplots()nnpatches, texts, autotexts = ax1.pie(sizes, explode=explode, labels=labels, autopct=%1.0f%%,n shadow=False, startangle=170)nax1.axis(equal) # Equal aspect ratio ensures that pie is drawn as a circle.nn# 重新設置字體大小nproptease = fm.FontProperties()nproptease.set_size(xx-small)n# font size include: 『xx-small』,x-small』,small』,medium』,『large』,『x-large』,『xx-large』 or number, e.g. 12nplt.setp(autotexts, fontproperties=proptease)nplt.setp(texts, fontproperties=proptease)nnplt.savefig(Demo_project_set_font.jpg)nplt.show()n

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3.2 設置顯示顏色，Method 1：

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from matplotlib import font_manager as fmnimport matplotlib as mplnn# Pie chart, where the slices will be ordered and plotted counter-clockwise:nlabels = s.indexnsizes = s.valuesnexplode = (0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0) # only "explode" the 1st slicennfig1, ax1 = plt.subplots(figsize=(6,6)) # 設置繪圖區域大小nna = np.random.rand(1,19)ncolor_vals = list(a[0])nmy_norm = mpl.colors.Normalize(-1, 1) # 將顏色數據的範圍設置為 [0, 1]nmy_cmap = mpl.cm.get_cmap(rainbow, len(color_vals)) # 可選擇合適的colormap，如：rainbownnpatches, texts, autotexts = ax1.pie(sizes, explode=explode, labels=labels, autopct=%1.0f%%,n shadow=False, startangle=170, colors=my_cmap(my_norm(color_vals)))nnax1.axis(equal) nn# 重新設置字體大小nproptease = fm.FontProperties()nproptease.set_size(xx-small)n# font size include: 『xx-small』,x-small』,small』,medium』,『large』,『x-large』,『xx-large』 or number, e.g. 12nplt.setp(autotexts, fontproperties=proptease)nplt.setp(texts, fontproperties=proptease)nnplt.savefig(Demo_project_set_color_1.jpg)nplt.show()n

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上面這種方法設置顏色時，但類別比較多時，部分顏色的填充會重複。

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有時候，我們可能想設置成連續的顏色，可以有另外一種方法來實現。

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3.3 設置顯示顏色， Method 2：

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from matplotlib import font_manager as fmnfrom matplotlib import cmnnlabels = s.indexnsizes = s.valuesn# explode = (0.2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0) # only "explode" the 1st slicennfig, ax = plt.subplots(figsize=(6,6)) # 設置繪圖區域大小nncolors = cm.rainbow(np.arange(len(sizes))/len(sizes)) # colormaps: Paired, autumn, rainbow, gray,spring,Darksnpatches, texts, autotexts = ax.pie(sizes, labels=labels, autopct=%1.0f%%,n shadow=False, startangle=170, colors=colors)nnax.axis(equal) nax.set_title(Shapes -------------------, loc=left)nn# 重新設置字體大小nproptease = fm.FontProperties()nproptease.set_size(xx-small)n# font size include: 『xx-small』,x-small』,small』,medium』,『large』,『x-large』,『xx-large』 or number, e.g. 12nplt.setp(autotexts, fontproperties=proptease)nplt.setp(texts, fontproperties=proptease)nnplt.savefig(Demo_project_set_color_2.jpg)nplt.show()n

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從上圖可以看出，顏色顯示是連續的，實現了我們想要的效果

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3.4 設置圖例（legend）

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from matplotlib import font_manager as fmnfrom matplotlib import cmnnlabels = s.indexnsizes = s.valuesn# explode = (0.2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0) # only "explode" the 1st slicennfig, ax = plt.subplots(figsize=(6,6)) # 設置繪圖區域大小nncolors = cm.rainbow(np.arange(len(sizes))/len(sizes)) # colormaps: Paired, autumn, rainbow, gray,spring,Darksnpatches, texts, autotexts = ax.pie(sizes, labels=labels, autopct=%1.0f%%,n shadow=False, startangle=170, colors=colors)nnax.axis(equal) nn# 重新設置字體大小nproptease = fm.FontProperties()nproptease.set_size(xx-small)n# font size include: 『xx-small』,x-small』,small』,medium』,『large』,『x-large』,『xx-large』 or number, e.g. 12nplt.setp(autotexts, fontproperties=proptease)nplt.setp(texts, fontproperties=proptease)nnax.legend(labels, loc=2)nnplt.savefig(Demo_project_set_legend_error.jpg)nplt.show()n

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從上面可看出，當類別較多時，圖例（legend）的位置擺放顯示有重疊，顯示有些問題，需要進行調整。

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3.5 重新設置圖例（legend）

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from matplotlib import font_manager as fmnfrom matplotlib import cmnnlabels = s.indexnsizes = s.valuesn# explode = (0.2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0) # only "explode" the 1st slicennfig, axes = plt.subplots(figsize=(10,5),ncols=2) # 設置繪圖區域大小nax1, ax2 = axes.ravel()nncolors = cm.rainbow(np.arange(len(sizes))/len(sizes)) # colormaps: Paired, autumn, rainbow, gray,spring,Darksnpatches, texts, autotexts = ax1.pie(sizes, labels=labels, autopct=%1.0f%%,n shadow=False, startangle=170, colors=colors)nnax1.axis(equal) nn# 重新設置字體大小nproptease = fm.FontProperties()nproptease.set_size(xx-small)n# font size include: 『xx-small』,x-small』,small』,medium』,『large』,『x-large』,『xx-large』 or number, e.g. 12nplt.setp(autotexts, fontproperties=proptease)nplt.setp(texts, fontproperties=proptease)nnax1.set_title(Shapes, loc=center)nn# ax2 只顯示圖例（legend）nax2.axis(off)nax2.legend(patches, labels, loc=center left)nnplt.tight_layout()nplt.savefig(Demo_project_set_legend_good.jpg)nplt.show()n

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3.6 將某些類別突出顯示

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• 將某些類別突出顯示

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• 控制label的顯示位置

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• 控制百分比的顯示位置

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• 控制突出位置的大小

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from matplotlib import font_manager as fmnfrom matplotlib import cmnnlabels = s.indexnsizes = s.valuesnexplode = (0.1,0,0,0,0,0,0,0,0,0,0,0,0,0.2,0,0,0,0.1,0) # "explode" ， show the selected slicennfig, axes = plt.subplots(figsize=(8,5),ncols=2) # 設置繪圖區域大小nax1, ax2 = axes.ravel()nncolors = cm.rainbow(np.arange(len(sizes))/len(sizes)) # colormaps: Paired, autumn, rainbow, gray,spring,Darksnpatches, texts, autotexts = ax1.pie(sizes, labels=labels, autopct=%1.0f%%,explode=explode,n shadow=False, startangle=170, colors=colors, labeldistance=1.2,pctdistance=1.03, radius=0.4)n# labeldistance: 控制labels顯示的位置n# pctdistance: 控制百分比顯示的位置n# radius: 控制切片突出的距離nnax1.axis(equal) nn# 重新設置字體大小nproptease = fm.FontProperties()nproptease.set_size(xx-small)n# font size include: 『xx-small』,x-small』,small』,medium』,『large』,『x-large』,『xx-large』 or number, e.g. 12nplt.setp(autotexts, fontproperties=proptease)nplt.setp(texts, fontproperties=proptease)nnax1.set_title(Shapes, loc=center)nn# ax2 只顯示圖例（legend）nax2.axis(off)nax2.legend(patches, labels, loc=center left)nnplt.tight_layout()n# plt.savefig("pie_shape_ufo.png", bbox_inches=tight)nplt.savefig(Demo_project_final.jpg)nplt.show()n

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