Python編程深度學習繪圖庫之matplotlib

2020-01-04 13:40:40

字體：大中小

來源：轉載

供稿：網友

matplotlib是python的一個開源的2D繪圖庫，它的原作者是John D. Hunter，因為在設計上借鑒了matlab，所以成為matplotlib。和Pillow一樣是被廣泛使用的繪圖功能，而在深度學習相關的部分，matplotlib得寵的多。這篇文章將簡單介紹一下如何安裝以及使用它來畫一些非常常見的統計圖形。

概要信息

Python編程,繪圖庫,matplotlib

注意事項：由于Python2支持到2020年，很多python庫都開始主要支持python3了，matplotlib的主分支也已經是python3了。而這篇文章中為了簡單，安裝和demo代碼依然是在python2.7上進行驗證的。

安裝

使用pip install即可直接安裝。安裝日志如下：

liumiaocn:tmp liumiao$ python -mpip install -U pipRequirement already up-to-date: pip in /usr/local/lib/python2.7/site-packages (10.0.1)liumiaocn:tmp liumiao$ liumiaocn:tmp liumiao$ python -mpip install -U matplotlibCollecting matplotlib Downloading https://files.pythonhosted.org/packages/61/38/d70e8bf77d5cb27d5f3595edd0b3978825063feadd023786d2591e393e6e/matplotlib-2.2.2-cp27-cp27m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl (13.7MB)  100% |████████████████████████████████| 13.7MB 2.1MB/s Collecting pyparsing!=2.0.4,!=2.1.2,!=2.1.6,>=2.0.1 (from matplotlib) Downloading https://files.pythonhosted.org/packages/6a/8a/718fd7d3458f9fab8e67186b00abdd345b639976bc7fb3ae722e1b026a50/pyparsing-2.2.0-py2.py3-none-any.whl (56kB)  100% |████████████████████████████████| 61kB 5.8MB/s Collecting backports.functools-lru-cache (from matplotlib) Downloading https://files.pythonhosted.org/packages/03/8e/2424c0e65c4a066e28f539364deee49b6451f8fcd4f718fefa50cc3dcf48/backports.functools_lru_cache-1.5-py2.py3-none-any.whlCollecting subprocess32 (from matplotlib) Downloading https://files.pythonhosted.org/packages/fa/60/b50459f291cae6bc1d0ff711b75e5130684fd3949370fdba78f6c57c1903/subprocess32-3.5.2-cp27-cp27m-macosx_10_6_intel.whlCollecting pytz (from matplotlib) Downloading https://files.pythonhosted.org/packages/dc/83/15f7833b70d3e067ca91467ca245bae0f6fe56ddc7451aa0dc5606b120f2/pytz-2018.4-py2.py3-none-any.whl (510kB)  100% |████████████████████████████████| 512kB 8.9MB/s Requirement not upgraded as not directly required: six>=1.10 in /usr/local/lib/python2.7/site-packages (from matplotlib) (1.11.0)Collecting python-dateutil>=2.1 (from matplotlib) Downloading https://files.pythonhosted.org/packages/cf/f5/af2b09c957ace60dcfac112b669c45c8c97e32f94aa8b56da4c6d1682825/python_dateutil-2.7.3-py2.py3-none-any.whl (211kB)  100% |████████████████████████████████| 215kB 7.2MB/s Collecting kiwisolver>=1.0.1 (from matplotlib) Downloading https://files.pythonhosted.org/packages/79/d8/94633718f3f77dcb638687a77ba199325a1cb158d2d4b00c9dc17f2b5c72/kiwisolver-1.0.1-cp27-cp27m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl (110kB)  100% |████████████████████████████████| 112kB 5.9MB/s Collecting cycler>=0.10 (from matplotlib) Downloading https://files.pythonhosted.org/packages/f7/d2/e07d3ebb2bd7af696440ce7e754c59dd546ffe1bbe732c8ab68b9c834e61/cycler-0.10.0-py2.py3-none-any.whlRequirement not upgraded as not directly required: numpy>=1.7.1 in /usr/local/lib/python2.7/site-packages (from matplotlib) (1.14.5)Requirement not upgraded as not directly required: setuptools in /usr/local/lib/python2.7/site-packages (from kiwisolver>=1.0.1->matplotlib) (39.2.0)Installing collected packages: pyparsing, backports.functools-lru-cache, subprocess32, pytz, python-dateutil, kiwisolver, cycler, matplotlibSuccessfully installed backports.functools-lru-cache-1.5 cycler-0.10.0 kiwisolver-1.0.1 matplotlib-2.2.2 pyparsing-2.2.0 python-dateutil-2.7.3 pytz-2018.4 subprocess32-3.5.2liumiaocn:tmp liumiao$

確認

liumiaocn:~ liumiao$ pip show matplotlibName: matplotlibVersion: 2.2.2Summary: Python plotting packageHome-page: http://matplotlib.orgAuthor: John D. Hunter, Michael DroettboomAuthor-email: matplotlib-users@python.orgLicense: BSDLocation: /usr/local/lib/python2.7/site-packagesRequires: pyparsing, backports.functools-lru-cache, subprocess32, pytz, six, python-dateutil, kiwisolver, cycler, numpyRequired-by: liumiaocn:~ liumiao$

使用

正弦函數

我們使用numpy和matplotlib可以非常簡單地就能夠畫出正弦的波形圖，具體代碼如下：

liumiaocn:plot liumiao$ cat plot-1.py #!/usr/local/bin/pythonimport numpy as npimport matplotlib.pyplot as plotprint("y=sin(x): x with range fo -4pi to 4pi")x=np.arange(-4*np.pi, 4*np.pi, 0.1)y=np.sin(x)#print sinplot.plot(x,y)plot.show()liumiaocn:plot liumiao$

執行&結果確認

liumiaocn:plot liumiao$ python plot-1.py y=sin(x): x with range fo -4pi to 4pi

Python編程,繪圖庫,matplotlib

直方圖

最簡單的直方圖的做法，可以通過bar或者hist來創建

liumiaocn:plot liumiao$ cat plot-2.py import numpy as npimport matplotlib.pyplot as pltx = np.arange(7)y = (10,15,24,7,14,30,20)plt.bar(x,y)plt.show()liumiaocn:plot liumiao$

Python編程,繪圖庫,matplotlib

餅圖

使用pie函數創建餅圖

liumiaocn:plot liumiao$ cat plot-3.py #!/usr/local/bin/pythonimport matplotlib.pyplot as pltdateinf = '06/01', '06/02', '06/03', '06/04', '06/05', '06/06', '06/07'bugnums = [11,22,7,29,24,15,18]plt.pie(bugnums, labels=dateinf)plt.show()liumiaocn:plot liumiao$

Python編程,繪圖庫,matplotlib