Logo Questions Linux Laravel Mysql Ubuntu Git Menu
 

Show the final y-axis value of each line with matplotlib

I'm drawing a graph with some lines using matplotlib and I want to display the final y value next to where each line ends on the right hand side like this: enter image description here

Any solutions or pointers to the relevant parts of the API? I'm quite stumped.

I'm using matplotlib 1.0.0 and the pyplot interface, e.g. pyplot.plot(xs, ys, f, xs_, ys_, f_).

like image 392
PAG Avatar asked Jun 11 '11 23:06

PAG


People also ask

How do I show values in MatPlotLib?

Steps. Create a list of numbers (x) that can be used to tick the axes. Get the axis using subplot() that helps to add a subplot to the current figure. Set the ticks on X and Y axes using set_xticks and set_yticks methods respectively and list x (from step 1).

What is the function of YLIM () in MatPlotLib?

ylim() Function. The ylim() function in pyplot module of matplotlib library is used to get or set the y-limits of the current axes.


1 Answers

While there's nothing wrong with Ofri's answer, annotate is intended especially for this purpose:

import matplotlib.pyplot as plt
import numpy as np

x = np.arange(61).astype(np.float)
y1 = np.exp(0.1 * x)
y2 = np.exp(0.09 * x)

plt.plot(x, y1)
plt.plot(x, y2)

for var in (y1, y2):
    plt.annotate('%0.2f' % var.max(), xy=(1, var.max()), xytext=(8, 0), 
                 xycoords=('axes fraction', 'data'), textcoords='offset points')

plt.show()

enter image description here

This places the text 8 points to the right of the right side of the axis, at the maximum y-value for each plot. You can also add in arrows, etc. See http://matplotlib.sourceforge.net/users/annotations_guide.html (You can also change the vertical alignment, if you want the text vertically centered on the given y-value. Just specify va='center'.)

Also, this doesn't rely on tick locations, so it will work perfectly for log plots, etc. Giving the location of the text in terms of the positions of the axis boundaries and its offset in points has a lot of advantages if you start rescaling the plot, etc.

like image 63
Joe Kington Avatar answered Nov 16 '22 00:11

Joe Kington