畫餅圖

from matplotlib import pyplot as plt 

#調節圖形大小，寬，高
plt.figure(figsize=(6,9))
#定義餅狀圖的標籤，標籤是列表
labels = [u'第一部分',u'第二部分',u'第三部分']
#每一個標籤佔多大，會自動去算百分比
sizes = [60,30,10]
colors = ['red','yellowgreen','lightskyblue']
#將某部分爆炸出來， 使用括號，將第一塊分割出來，數值的大小是分割出來的與其餘兩塊的間隙
explode = (0.05,0,0)

patches,l_text,p_text = plt.pie(sizes,explode=explode,labels=labels,colors=colors,
                                labeldistance = 1.1,autopct = '%3.1f%%',shadow = False,
                                startangle = 90,pctdistance = 0.6)

#labeldistance，文本的位置離遠點有多遠，1.1指1.1倍半徑的位置
#autopct，圓裏面的文本格式，%3.1f%%表示小數有三位，整數有一位的浮點數
#shadow，餅是否有陰影
#startangle，起始角度，0，表示從0開始逆時針轉，爲第一塊。通常選擇從90度開始比較好看
#pctdistance，百分比的text離圓心的距離
#patches, l_texts, p_texts，爲了獲得餅圖的返回值，p_texts餅圖內部文本的，l_texts餅圖外label的文本

#改變文本的大小
#方法是把每個text遍歷。調用set_size方法設置它的屬性
for t in l_text:
    t.set_size=(30)
for t in p_text:
    t.set_size=(20)
# 設置x，y軸刻度一致，這樣餅圖才能是圓的
plt.axis('equal')
plt.legend()
plt.show()

做者：Kedi
連接：http://www.jianshu.com/p/0a76c94e9db7
來源：簡書
著做權歸做者全部。商業轉載請聯繫做者得到受權，非商業轉載請註明出處。

　　

 

python 畫圖--餅圖

這是python畫圖系列第三篇--餅圖

畫餅圖用到的方法爲：

matplotlib.pyplot.pie()

 

參數爲：

 

pie(x, explode=None, labels=None,
    colors=('b', 'g', 'r', 'c', 'm', 'y', 'k', 'w'),
    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 )

參數說明：

 

 

x       (每一塊)的比例，若是sum(x) > 1會使用sum(x)歸一化

labels  (每一塊)餅圖外側顯示的說明文字

explode (每一塊)離開中心距離

startangle  起始繪製角度,默認圖是從x軸正方向逆時針畫起,如設定=90則從y軸正方向畫起

shadow  是否陰影

labeldistance label繪製位置,相對於半徑的比例, 如<1則繪製在餅圖內側

autopct 控制餅圖內百分比設置,能夠使用format字符串或者format function

        '%1.1f'指小數點先後位數(沒有用空格補齊)

pctdistance 相似於labeldistance,指定autopct的位置刻度

radius  控制餅圖半徑

返回值:
若是沒有設置autopct,返回(patches, texts)
若是設置autopct,返回(patches, texts, autotexts)

patches -- list --matplotlib.patches.Wedge對象

texts autotexts -- matplotlib.text.Text對象

 

 

下面是一個簡單的示例：

 

# -*- coding: utf-8 -*-
import numpy as np
import matplotlib.mlab as mlab
import matplotlib.pyplot as plt
labels=['China','Swiss','USA','UK','Laos','Spain']
X=[222,42,455,664,454,334]

fig = plt.figure()
plt.pie(X,labels=labels,autopct='%1.2f%%') #畫餅圖（數據，數據對應的標籤，百分數保留兩位小數點）
plt.title("Pie chart")


plt.show()
plt.savefig("PieChart.jpg")

下面是結果：

 

 

下面是另外一個示例：

 

# -*- coding: utf-8 -*-
import numpy as np
import matplotlib.pyplot as plt
import matplotlib as mpl

def draw_pie(labels,quants):
    # make a square figure
    plt.figure(1, figsize=(6,6))
    # For China, make the piece explode a bit
    expl = [0,0.1,0,0,0,0,0,0,0,0]   #第二塊即China離開圓心0.1
    # Colors used. Recycle if not enough.
    colors  = ["blue","red","coral","green","yellow","orange"]  #設置顏色（循環顯示）
    # Pie Plot
    # autopct: format of "percent" string;百分數格式
    plt.pie(quants, explode=expl, colors=colors, labels=labels, autopct='%1.1f%%',pctdistance=0.8, shadow=True)
    plt.title('Top 10 GDP Countries', bbox={'facecolor':'0.8', 'pad':5})
    plt.show()
    plt.savefig("pie.jpg")
    plt.close()

# quants: GDP

# labels: country name

labels   = ['USA', 'China', 'India', 'Japan', 'Germany', 'Russia', 'Brazil', 'UK', 'France', 'Italy']

quants   = [15094025.0, 11299967.0, 4457784.0, 4440376.0, 3099080.0, 2383402.0, 2293954.0, 2260803.0, 2217900.0, 1846950.0]

draw_pie(labels,quants)

 

 

官方文檔：

連接：http://matplotlib.org/api/pyplot_api.html

 

 

matplotlib.pyplot.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)

Plot a pie chart.

Call signature:

pie(x, explode=None, labels=None, colors=('b', 'g', 'r', 'c', 'm', 'y', 'k', 'w'), 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 ) 

Make a pie chart of array x. The fractional area of each wedge is given by x/sum(x). If sum(x) <= 1, then the values of x give the fractional area directly and the array will not be normalized. The wedges are plotted counterclockwise, by default starting from the x-axis.

Keyword arguments:

explode: [ None | len(x) sequence ]

If not None, is a  len(x) array which specifies the fraction of the radius with which to offset each wedge.

colors: [ None | color sequence ]

A sequence of matplotlib color args through which the pie chart will cycle.

labels: [ None | len(x) sequence of strings ]

A sequence of strings providing the labels for each wedge

autopct: [ None | format string | format function ]

If not None, is a string or function used to label the wedges with their numeric value. The label will be placed inside the wedge. If it is a format string, the label will be  fmt%pct. If it is a function, it will be called.

pctdistance: scalar

The ratio between the center of each pie slice and the start of the text generated by autopct. Ignored if autopct is None; default is 0.6.

labeldistance: scalar

The radial distance at which the pie labels are drawn

shadow: [ False | True ]

Draw a shadow beneath the pie.

startangle: [ None | Offset angle ]

If not None, rotates the start of the pie chart by angle degrees counterclockwise from the x-axis.

radius: [ None | scalar ] The radius of the pie, if radius is None it will be set to 1.

counterclock: [ False | True ]

Specify fractions direction, clockwise or counterclockwise.

wedgeprops: [ None | dict of key value pairs ]

Dict of arguments passed to the wedge objects making the pie. For example, you can pass in wedgeprops = { ‘linewidth’ : 3 } to set the width of the wedge border lines equal to 3. For more details, look at the doc/arguments of the wedge object. By default  clip_on=False.

textprops: [ None | dict of key value pairs ]

Dict of arguments to pass to the text objects.

center: [ (0,0) | sequence of 2 scalars ] Center position of the chart.

frame: [ False | True ]

Plot axes frame with the chart.

The pie chart will probably look best if the figure and axes are square, or the Axes aspect is equal. e.g.:

figure(figsize=(8,8)) ax = axes([0.1, 0.1, 0.8, 0.8]) 

or:

axes(aspect=1) 

Return value:

If autopct is None, return the tuple (patches, texts):

• patches is a sequence of matplotlib.patches.Wedge instances
• texts is a list of the label matplotlib.text.Text instances.

If autopct is not None, return the tuple (patches, texts, autotexts), where patches and texts are as above, and autotexts is a list of Textinstances for the numeric labels.

Notes

In addition to the above described arguments, this function can take a data keyword argument. If such a data argument is given, the following arguments are replaced by data[<arg>]:

• All arguments with the following names: ‘colors’, ‘x’, ‘explode’, ‘labels’.

Additional kwargs: hold = [True|False] overrides default hold state