CODEWITHSUNDEEP
pythonmatplotlib
Simd
Simd

Reputation: 21254

Can you add a number to a plotted line in matplotlib?

I am using matplotlib.pyplot to plot different lines. I can add a legend with a label to tell which line is which by color. Unfortunately I am color blind. Is it possible to write a number embedded in each line instead? The numbers could look like this.

enter image description here

These could then identify each line.

Upvotes: 2

Views: 4018

Answers (2)

warped
warped

Reputation: 9482

My answer is based on this question.

You can use latex math symbols in matplotlib. Since $1$ counts as latex math symbol, you can use it as marker.

Example with 0,1,2: 

x, y, = np.arange(10), np.arange(10)

for a in range(3):

    plt.plot(x, a*y, alpha=0.5, marker='${}$'.format(a), markersize=10, label=a)

plt.legend()
plt.show()

enter image description here

edit

Plotting number only once on the curve

x, y, = np.arange(10), np.arange(10)

colors = ['teal', 'darkslateblue', 'orange']

for a in range(3):

    plt.plot(x, a*y, c=colors[a])
    plt.plot(x[a+3], a*y[a+3], alpha=0.5, marker='${}$'.format(a), markersize=10, label=a, c=colors[a])

plt.legend()
plt.show()

enter image description here

Upvotes: 1

alexpiers
alexpiers

Reputation: 726

There is a nice little package matplotlib-label-lines that accomplishes this (the code is here on github).

After installing this package, your code could look something like this:

import numpy as np
import matplotlib.pyplot as plt
import labellines

x = np.linspace(0, 5, 100)

fig, ax = plt.subplots(1, 1)
ax.plot(x, x**2, linewidth=2, label="line example")
labellines.labelLines(ax.get_lines())

plt.show()

Which would give you something like this.

You could also you different line style, instead of color, in your legend. enter image description here

Upvotes: 2

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