matplotlib画图基本设置

1.matplotlib画出的图中的各个组成部分

2.程序与解说

• 解说

  plt.figure(figsize=(9.6,4.1),facecolor='gray',edgecolor='black')

  设置图片大小9.6x4.1英寸($1in\approx8.13cm$),facecolor背景颜色，edgecolor边框线颜色。

  plt.subplot(1,2,1)
  plt.title('(a)')
  plt.xlim((-11,11))
  plt.ylim((-200000,200000))
  plt.xlabel(r'$\alpha$')
  plt.ylabel(r'$\beta$')
  plt.yscale('linear')
  plt.minorticks_on()
  plt.tick_params(which='minor',direction='in',width=2,length=4)
  plt.tick_params(which='major',direction='out',width=4,length=6)
  plt.tick_params(top='off',bottom='on',left='on',right='off')
  plt.tick_params(labeltop='off',labelbottom='on',labelleft='on',labelright='off')
  
  plt.subplot(1,2,2)
  plt.title('(b)')
  plt.xlim((-15,15))
  plt.ylim((-300000,300000))
  plt.xlabel('this is x',fontsize=12)
  plt.ylabel('this is y')

  见下图,xlim，ylim指定坐标轴的取值范围，title指定图的名称，xlabel,ylabel设置坐标轴名字及其字体大小，支持Latex语法。yscale对坐标轴刻度值的函数，有log等选项。 minorticks_on打开最小刻度线，tick_params(which='minor',direction='in',width=2,length=4)控制主次刻度线的长度，宽度和朝向，(top='off',bottom='on',left='on',right='off')设置主刻度线在上下左右四条边上是否显示，tick_params(labeltop='off',labelbottom='on',labelleft='on',labelright='off')设置刻度值(ticklabel)在上下左右四条边上是否显示。

  

  plt.xticks([])
  plt.yticks([-200000,-100000,0,100000,200000],
         [r'$big$', r'$zero$',r'small',r'$really small$',r'fine'])

  如下图，xtick([])关闭x轴坐标刻度,yticks([...1],[...2])设置刻度值名称，支持Latex语法。
  

  

  plt.axis('off')

  如下图，axis('off')关闭坐标轴显示。
  

  

     plt.grid(True,color='gray',linestyle='--',linewidth=0.8,alpha=0.9)
     ax=plt.gca()
     ax.xaxis.grid(True,color='r',linestyle='--',linewidth=1.2,alpha=0.3)#alpha is transparencys

  如下图，grid打开网格线，ax.xaxis.grid()打开x轴的网格线，并设置格式。alpha是透明度，值越大透明度越，越不透明。
  

  

   ax.xaxis.set_ticks_position('top')
   ax.spines['left'].set_linewidth(1.6)
   ax.spines['right'].set_visible(False)
   ax.spines['bottom'].set_visible(False)
   ax.spines['top'].set_linestyle('--')
   ax.spines['top'].set_color('blue')
   ax.spines['left'].set_position(('data',0))
   ax.spines['top'].set_position(('data',0))
  
   xMajorLocator=MultipleLocator(4)
   xMinorLocator=MultipleLocator(1.0)
   yMajorLocator=MultipleLocator(100000)
   yMinorLocator=MultipleLocator(10000)
   ax.xaxis.set_major_locator(xMajorLocator)
   ax.xaxis.set_minor_locator(xMinorLocator)
   ax.yaxis.set_major_locator(yMajorLocator)
   ax.yaxis.set_minor_locator(yMinorLocator)

  for tick in ax.xaxis.get_major_ticks():
      tick.label1.set_fontsize(15)

  如下图,ax.xaxis.set_ticks_position('top')设置x轴的刻度是位于哪一条边上，一般选top或者bottom,ax.spines设置上下左右四条边的颜色、线型、位置等，ax.xaxis.set_major_locator等，设置坐标轴主次刻度值的分辨率。tick.label1.set_fontsize(15)设置刻度值字体大小。
  

  

   ax.spines['left'].set_linewidth(2.6) 
   ax.axes.get_yaxis().set_visible(False)

  如下图,ax.axes.get_yaxis().set_visible(False)设置坐标轴是上的刻度不可见，但轴仍在。
  

  
  

  plt.plot(x,y1,color='r',linewidth=0.6,label='oddpower')
  plt.plot(x,y3,color='g',linewidth=1.3,linestyle='--',label='evenpower')
  plt.legend(loc='down left')

  如下图，画图并指定图示说明的位置。
  

  
  

  plt.subplots_adjust(top=0.92, bottom=0.12, left=0.12, right=0.95, hspace=0.25,wspace=0.35)
  plt.savefig('tutorial0.png',dpi=300)

  调整子图之间的相对位置，并保存图片，指定dpi，dpi越大，图片越清晰。

• 程序

  
  #!/usr/bin/env python2
  
  
  # -*- coding: utf-8 -*-
  
  """
  Created on Tue May 22 16:49:46 2018
  @author: rd
  """
  from __future__ import division
  import numpy as np
  import matplotlib.pyplot as plts
  from matplotlib.ticker import MultipleLocator
  
  x=np.linspace(-11,11,120)
  y1=x+x**3+x**5
  y2=x**2+x**4+x**6
  y3=x**2+x**6
  
  plt.figure(figsize=(9.6,4.1),facecolor='gray',edgecolor='black')
  plt.subplot(1,2,1)
  plt.xlim((-14,14))
  plt.ylim((-200000,200000))
  plt.xlabel('this is x',fontsize=12)
  plt.ylabel('this is y')
  plt.minorticks_on()
  plt.tick_params(which='minor',direction='in',width=2,length=4)
  plt.tick_params(which='major',direction='out',width=4,length=6)
  plt.tick_params(top='off',bottom='on',left='on',right='off')
  plt.tick_params(labeltop='off',labelbottom='on',labelleft='on',labelright='off')
  
  #plt.xticks([])
  
  
  #plt.yticks([])
  
  
  #plt.xticks([-10,-5,0,5,10],[])
  
  
  #plt.xticks([-9,-6,-3,0,3,6,9],[])
  
  plt.grid(True,color='gray',linestyle='--',linewidth=0.8,alpha=0.8)#open the grid
  plt.yscale('linear')
  plt.plot(x,y1,color='r')
  plt.plot(x,y3,color='g',linewidth=1.3,linestyle='--')
  
  #plt.axis('off')
  
  ax=plt.gca()
  ax.xaxis.grid(color='r',linestyle='--',linewidth=1.2,alpha=0.3)#alpha is transparencys
  ax.xaxis.set_ticks_position('bottom')
  
  #ax.patch.set_facecolor('gray')
  
  for tick in ax.xaxis.get_major_ticks():
      tick.label1.set_fontsize(10)
  ax.spines['left'].set_linewidth(1.6)#line of the axes
  ax.spines['right'].set_visible(False)
  ax.spines['top'].set_linestyle('--')
  ax.spines['top'].set_color('blue')
  ax.spines['bottom'].set_linewidth(1.6)
  
  #ax.spines['left'].set_position(('data',0))#the position of the
  
  
  #ax.spines['bottom'].set_position(('data',0))# axis
  
  xMajorLocator=MultipleLocator(4)
  xMinorLocator=MultipleLocator(1.0)
  yMajorLocator=MultipleLocator(100000)
  yMinorLocator=MultipleLocator(10000)
  ax.xaxis.set_major_locator(xMajorLocator)
  ax.xaxis.set_minor_locator(xMinorLocator)
  ax.yaxis.set_major_locator(yMajorLocator)
  ax.yaxis.set_minor_locator(yMinorLocator)
  plt.yticks([-200000,-100000,0,100000,200000],
             [r'$big$', r'$zero$',r'small',r'$really small$',r'fine'])
  
  #ax.axes.get_yaxis().set_visible(False) #make the yticks is unvisible
  
  
  #ax.axes.get_yaxis().set_visible(False)
  
  plt.legend('upper right')
  
  plt.subplot(1,2,2)
  plt.minorticks_off()
  
  #plt.xticks([])
  
  plt.tick_params(which='both',direction='out')
  plt.plot(x,y2,color='b')
  plt.show()
  plt.subplots_adjust(top=0.92, bottom=0.12, left=0.12, right=0.95, hspace=0.25,
                      wspace=0.35)
  plt.savefig('tutorial0.png',dpi=600)

---

refer

[1] https://blog.youkuaiyun.com/Fortware/article/details/51934814

[2] http://python.jobbole.com/85106/

[3] https://matplotlib.org/tutorials/introductory/usage.html