56

Is it possible, with Matplotlib, to print the values of each point on the graph?

For example, if I have:

x = numpy.range(0,10)
y = numpy.array([5,3,4,2,7,5,4,6,3,2])
pyplot.plot(x,y)

How can I display y values on the plot (e.g. print a 5 near the (0,5) point, print a 3 near the (1,3) point, etc.)?

Charles Brunet
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2 Answers2

87

You can use the annotate command to place text annotations at any x and y values you want. To place them exactly at the data points you could do this

import numpy
from matplotlib import pyplot

x = numpy.arange(10)
y = numpy.array([5,3,4,2,7,5,4,6,3,2])

fig = pyplot.figure()
ax = fig.add_subplot(111)
ax.set_ylim(0,10)
pyplot.plot(x,y)
for i,j in zip(x,y):
    ax.annotate(str(j),xy=(i,j))

pyplot.show()

If you want the annotations offset a little, you could change the annotate line to something like

ax.annotate(str(j),xy=(i,j+0.5))
Stephen Terry
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    +1 Just as a side note, annotate has "offseting the annotations a little" built-in. Just do `ax.annotate(str(j), xy=(i,j), xytext=(10,10), textcoords='offset points')` to offset the annotations by 10 _points_ in the x and y directions. This is often more useful than offsetting in data coordinates (though that's also an option). – Joe Kington Jun 14 '11 at 05:51
28

Use pyplot.text() (import matplotlib.pyplot as plt)

import matplotlib.pyplot as plt

x=[1,2,3]
y=[9,8,7]

plt.plot(x,y)
for a,b in zip(x, y): 
    plt.text(a, b, str(b))
plt.show()
François B.
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Marvin W
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