Matplotlib 简单绘直方图、饼图、极坐标图、气泡图

1 直方图：效果图和代码如下：

import numpy as np
import matplotlib.mlab as mlab
import matplotlib.pyplot as plt

# example data
mu = 100
sigma = 15
x = mu + sigma*np.random.randn(1000)

#直方图的条数
num_bins = 50
n, bins, patches = plt.hist(x, num_bins, normed=1, facecolor = "b", alpha=0.5)
#添加一个拟合曲线,返回概率密度函数
y = mlab.normpdf(bins, mu, sigma)
plt.plot(bins,y,"r--")
#fontproperties显示中文simHei Lishu STSong Kaiti FangSong YouYuan 
plt.xlabel("横轴",fontproperties = "simHei",fontsize = 14)
plt.ylabel("纵轴",fontproperties = "simHei",fontsize = 14)
plt.title("simple histogram")
#text(x,y,str)指定图像位置输入文字；latex语法$$添加公式
plt.text(100,0.033,"$\mu=100$,$\sigma=15$")
#调整图像的间距，防止y轴数值与label重合
plt.subplots_adjust(left=0.15)
plt.show()

主要代码 hist函数：

n, bins, patches = plt.hist(arr,bins=10,normed=0,facecolor="black",edgecolor="black",alpha=1,histtype="bar")

参数：arr 直方图的一维数组，bins：直方图的柱数，默认为10；normed 归一化，默认为0,facecolor直方图颜色；edgecolor边框颜色 alpha：透明度；histtype：类型“bar”“barstacked”“step”“stepfilled”

返回值：n直方图向量，bins各个bin区间范围，patches：list类型，每个bin里包含的数据

2 饼图

import matplotlib.pyplot as plt

labels = "Fogs","Hogs","Dogs","Logs"
sizes = [15,30,45,10]
colors = ["y","r","c","b"]
explode = (0,0.1,0,0)#分离 突出显示第二块
#绘图 设置数据，突出，颜色，标签，数据显示格式，阴影等
plt.pie(sizes,explode=explode,labels=labels,colors=colors,autopct="%1.1f%%",
        shadow=False,startangle=90)
plt.axis("equal")#正圆效果，轴长度相同
plt.show()

3 极坐标图：这个实际中不常用，效果很好看所以学学。

#面向对象绘制极坐标图:
import numpy as np
import matplotlib.pyplot as plt

N = 20 #数据个数
theta = np.linspace(0.0,2*np.pi,N,endpoint=False)#0-360度，按个数等分
radii = 10*np.random.rand(N)
width = np.pi/4*np.random.rand(N)

ax = plt.subplot(111,projection="polar")#一个绘图区域，绘制极坐标
#绘制起始位置，中心点向边缘绘制的长度，每个绘图区域面积
bars = ax.bar(theta,radii,width,bottom=0.0)
#修改每个绘图区的颜色
for r,bar in zip(radii,bars):
    bar.set_facecolor(plt.cm.viridis(r/10.))
    bar.set_alpha(0.5)

plt.show()

4 气泡图：

气泡图是散点图的一种变体，通过每个点的面积大小，反映第三维数据。

import numpy as np
import matplotlib.pyplot as plt

a = 100*np.random.randn(33).reshape(3,11)

fig, ax = plt.subplots()
colors = ["#99cc01","#ffff01","#0000fe","#a6a6a6","#d91021","#fff161","#0d8ecf"
          ,"#fa4d3d","#d2d2d2","#ffde45","#9b59b6"]
#分别设置X轴值，Y轴值，以及第三个参数值大小来显示气泡大小
ax.scatter(a[0,:],a[1,:],s=100*a[2,:],color=colors,alpha=0.6)
#ax.plot(10*np.random.randn(100),10*np.random.randn(100),"o")
ax.set_title("随机气泡图",fontproperties = "simHei",fontsize = 16)
ax.set_xlabel("随机X值",fontproperties = "simHei",fontsize = 14)
ax.set_ylabel("随机y值",fontproperties = "simHei",fontsize = 14)
ax.grid(True)
fig.tight_layout()
plt.show()

python路漫漫，学习无止尽。