python matplotlib

背景：

1）数据可视化

目前还处于python入门阶段，主要想通过numpy、matplotlib进行数据可视化。

安装：

操作系统：windows7

1）python2.7 安装numpy、matplotlib

pip安装numpy没有问题

pip通过tar安装matplotlib不成功，提示缺少freetype、png，反正挺麻烦的。

2）python3.5安装numpy、matplotlib

pip直接搞定，安装matplotlib的时候会安装关联的模块。

安装numpy和matplotlib后，pip list展示安装了哪些模块。

使用：

网上随便找了个例子，如下：

import numpy as np
import matplotlib.pyplot as plt

N = 5
menMeans = (20, 35, 30, 35, 27)
menStd =   (2, 3, 4, 1, 2)

ind = np.arange(N)  # the x locations for the groups
width = 0.35       # the width of the bars

fig, ax = plt.subplots()
rects1 = ax.bar(ind, menMeans, width, color='r', yerr=menStd)

womenMeans = (25, 32, 34, 20, 25)
womenStd =   (3, 5, 2, 3, 3)
rects2 = ax.bar(ind+width, womenMeans, width, color='y', yerr=womenStd)

# add some
ax.set_ylabel('Scores')
ax.set_title('Scores by group and gender')
ax.set_xticks(ind+width)
ax.set_xticklabels( ('G1', 'G2', 'G3', 'G4', 'G5') )

ax.legend( (rects1[0], rects2[0]), ('Men', 'Women') )

def autolabel(rects):
    # attach some text labels
    for rect in rects:
        height = rect.get_height()
        ax.text(rect.get_x()+rect.get_width()/2., 1.05*height, '%d'%int(height),
                ha='center', va='bottom')

autolabel(rects1)
autolabel(rects2)

plt.show()

　　

运行图：

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