Many a times, I needed multiple plots in the same view as it helps in analyzing data in proper way. Also, if you want to present this data somewhere, it helps to plot two graphs together.
One alternative to subplots is using multiple axis and plotting 2 data points on the same graph but this might distort the view. Each has its own applications. In this article, we will look at how to plot subplots.
Sytax is as below
subplot(nrows ncols index)
Here, nrows and ncols need not be same for all plots. Its only specific to current plot. Please refer to third example in this article
- Plotting three graphs using matplotlib
| ################################################################################################ | |
| # name: subplot-01.py | |
| # desc: Fsubplot using matplotlib | |
| # date: 2018-07-1 | |
| # Author: conquistadorjd | |
| ################################################################################################ | |
| import matplotlib.pyplot as plt | |
| import numpy as np | |
| print('*** Program Started ***') | |
| t= np.arange(1,17,1) | |
| y1= np.random.randint(1, 16,size=16) | |
| y2= np.random.randint(1, 32,size=16) | |
| y3= np.random.randint(1, 48,size=16) | |
| ax1 = plt.subplot(311) | |
| plt.plot(t, y1,label="Jagur") | |
| plt.xlabel('Sample x Axis') | |
| plt.ylabel('Sample y Axis') | |
| plt.legend(loc=2) | |
| plt.title('subplot') | |
| # plt.grid(True) | |
| # plt.yscale('log') | |
| # make these tick labels invisible | |
| # plt.setp(ax1.get_xticklabels(), visible=False , fontsize=10) | |
| # share x only | |
| ax2 = plt.subplot(312, sharex=ax1) | |
| plt.plot(t, y2,label="Range Rover") | |
| plt.xlabel('Sample x Axis') | |
| plt.ylabel('Sample y Axis') | |
| plt.legend(loc=2) | |
| # plt.title('linear') | |
| # make these tick labels invisible | |
| # plt.setp(ax2.get_xticklabels(), visible=False, fontsize=10) | |
| # share x and y | |
| ax3 = plt.subplot(313, sharex=ax1) | |
| plt.plot(t, y3, label="Land Rover") | |
| plt.xlabel('Sample x Axis') | |
| plt.ylabel('Sample y Axis') | |
| plt.legend(loc=2) | |
| # make these tick labels visible with required font size | |
| # plt.setp(ax3.get_xticklabels(), visible=True, fontsize=10) | |
| # Saving image | |
| plt.savefig('subplot-01.png') | |
| # In case you dont want to save image but just displya it | |
| plt.show() | |
| print('*** Program ended ***') |
Output is as below
- Plotting 4 graphs in 2*2 grid using matplotlibb
| ################################################################################################ | |
| # name: subplot-02.py | |
| # desc: Subplot using matplotlib grid 2*2 | |
| # date: 2018-07-1 | |
| # Author: conquistadorjd | |
| ################################################################################################ | |
| import matplotlib.pyplot as plt | |
| import numpy as np | |
| print('*** Program Started ***') | |
| t= np.arange(1,17,1) | |
| y1= np.random.randint(1, 16,size=16) | |
| y2= np.random.randint(1, 32,size=16) | |
| y3= np.random.randint(1, 48,size=16) | |
| y4= np.random.randint(1, 48,size=16) | |
| ax1 = plt.subplot(221) | |
| plt.plot(t, y1,label="Jagur") | |
| plt.xlabel('Sample x Axis') | |
| plt.ylabel('Sample y Axis') | |
| plt.legend(loc=2) | |
| plt.title('subplot') | |
| # make these tick labels invisible | |
| # plt.setp(ax1.get_xticklabels(), visible=False , fontsize=10) | |
| # share x only | |
| ax2 = plt.subplot(222, sharex=ax1, sharey=ax1) | |
| plt.plot(t, y2,label="Range Rover") | |
| plt.xlabel('Sample x Axis') | |
| plt.ylabel('Sample y Axis') | |
| plt.legend(loc=2) | |
| plt.title('subplot') | |
| # make these tick labels invisible | |
| # plt.setp(ax2.get_xticklabels(), visible=False, fontsize=10) | |
| # share x and y | |
| ax3 = plt.subplot(223,sharex=ax1, sharey=ax1) | |
| plt.plot(t, y3,label="Land Rover") | |
| plt.xlabel('Sample x Axis') | |
| plt.ylabel('Sample y Axis') | |
| plt.legend(loc=2) | |
| # plt.title('subplot') | |
| # make these tick labels visible with required font size | |
| # plt.setp(ax3.get_xticklabels(), visible=True, fontsize=10) | |
| # share x and y | |
| ax4 = plt.subplot(224,sharex=ax1, sharey=ax1) | |
| plt.plot(t, y4,label="Tata Motors") | |
| plt.xlabel('Sample x Axis') | |
| plt.ylabel('Sample y Axis') | |
| plt.legend(loc=2) | |
| # plt.title('subplot') | |
| # make these tick labels visible with required font size | |
| # plt.setp(ax3.get_xticklabels(), visible=True, fontsize=10) | |
| # Saving image | |
| plt.savefig('subplot-02.png') | |
| # In case you dont want to save image but just displya it | |
| plt.show() | |
| print('*** Program ended ***') |
Output is as below
- Plotting 3 graphs using matplotlib
| ##################################################################################################################### | |
| # name: subplot-03.py | |
| # desc: First row having two columns and second row having only 1 column | |
| # date: 2018-07-1 | |
| # Author: conquistadorjd | |
| ###################################################################################################################### | |
| import matplotlib.pyplot as plt | |
| import numpy as np | |
| print('*** Program Started ***') | |
| t= np.arange(1,17,1) | |
| y1= np.random.randint(1, 16,size=16) | |
| y2= np.random.randint(1, 32,size=16) | |
| y3= np.random.randint(1, 48,size=16) | |
| y4= np.random.randint(1, 48,size=16) | |
| ax1 = plt.subplot(221) | |
| plt.plot(t, y1,label="Jagur") | |
| plt.xlabel('Sample x Axis') | |
| plt.ylabel('Sample y Axis') | |
| plt.legend(loc=2) | |
| plt.title('subplot') | |
| # make these tick labels invisible | |
| # plt.setp(ax1.get_xticklabels(), visible=False , fontsize=10) | |
| # share x only | |
| ax2 = plt.subplot(222, sharex=ax1, sharey=ax1) | |
| plt.plot(t, y2,label="Range Rover") | |
| plt.xlabel('Sample x Axis') | |
| plt.ylabel('Sample y Axis') | |
| plt.legend(loc=2) | |
| plt.title('subplot') | |
| # make these tick labels invisible | |
| # plt.setp(ax2.get_xticklabels(), visible=False, fontsize=10) | |
| # share x and y | |
| ax3 = plt.subplot(212,sharex=ax1, sharey=ax1) | |
| plt.plot(t, y3,label="Land Rover") | |
| plt.xlabel('Sample x Axis') | |
| plt.ylabel('Sample y Axis') | |
| plt.legend(loc=2) | |
| # plt.title('subplot') | |
| # make these tick labels visible with required font size | |
| # plt.setp(ax3.get_xticklabels(), visible=True, fontsize=10) | |
| # Saving image | |
| plt.savefig('subplot-03.png') | |
| # In case you dont want to save image but just displya it | |
| plt.show() | |
| print('*** Program ended ***') |
Output is as below
If you have noticed, in third example, subplot columns are different as compared to first one. This is because, we wanted to plot a single graph in second row.
Also note that we have used sharex=ax1, sharey=ax1 to maintain same scale on all columns. If scales are different, it does not gives us relative analysis.