Javier Javier - 4 months ago 38
Python Question

Matplotlib: How to put individual tags for a scatter plot

I am trying to do a scatter plot in matplotlib and I couldn't find a way to add tags to the points. For example:

scatter1=plt.scatter(data1["x"], data1["y"], marker="o",
c="blue",
facecolors="white",
edgecolors="blue")


I want for the points in "y" to have labels as "point 1", "point 2", etc. I couldn't figure it out.

Answer

Perhaps use plt.annotate:

import numpy as np
import matplotlib.pyplot as plt

N = 10
data = np.random.random((N, 4))
labels = ['point{0}'.format(i) for i in range(N)]
plt.subplots_adjust(bottom = 0.1)
plt.scatter(
    data[:, 0], data[:, 1], marker = 'o', c = data[:, 2], s = data[:, 3]*1500,
    cmap = plt.get_cmap('Spectral'))
for label, x, y in zip(labels, data[:, 0], data[:, 1]):
    plt.annotate(
        label, 
        xy = (x, y), xytext = (-20, 20),
        textcoords = 'offset points', ha = 'right', va = 'bottom',
        bbox = dict(boxstyle = 'round,pad=0.5', fc = 'yellow', alpha = 0.5),
        arrowprops = dict(arrowstyle = '->', connectionstyle = 'arc3,rad=0'))

plt.show()

enter image description here