Mention label in matplotlib plot based on categorical class

Question

I want to put label on plot. my code is like

import matplotlib.pyplot as plt
x1 = [1,2,3,4,5,6,7,8,9,10]
x2 = [7,3,2,4,1,4,3,5,8,4]
y  = [0,1,1,0,1,0,0,1,0,1]
plt.scatter(x1,x2,c=y)
plt.show()

Output:

I want to put legend label 0 and 1 on graph. its good if label is False or true ?

It is appreciated if answer is without any iterations

It is not clear what kind of labels you want to put and where. — DYZ, Jul 02 '17 at 07:02
Do you mean you want to put a 1 by each of the yellow dots and a 0 by each of the dark dots? — OldGeeksGuide, Jul 02 '17 at 07:05
Try checking these links - https://matplotlib.org/users/annotations_intro.html and https://matplotlib.org/api/text_api.html#module-matplotlib.text — OldGeeksGuide, Jul 02 '17 at 07:15
I want plot legend showing o-true and o-false where o filled with respected color — GIRISH kuniyal, Jul 02 '17 at 16:08

score 1 · Accepted Answer · answered Jul 02 '17 at 22:15

In principle questions like matplotlib scatterplot with legend or Matplotlib scatter plot with legend show how to get a legend for a scatter plot.

Since you explicitely ask not to have iterations, you may of course replace iterations by mappings.

import matplotlib.pyplot as plt
import numpy as np

x1 = [1,2,3,4,5,6,7,8,9,10]
x2 = [7,3,2,4,1,4,3,5,8,4]
y  = [0,1,1,0,1,0,0,1,0,1]
plt.scatter(x1,x2,c=y, cmap="viridis")

yunique = np.unique(y).astype(float)
handles = list(map(lambda i: plt.plot([], 
                color=plt.cm.viridis(i),marker="o", ls="")[0], yunique))
labels = list(map(str, yunique.astype(bool)))
plt.legend(handles=handles, labels=labels)

plt.show()

Note that this is a purely academic example and it is much easier to use a for-loop.

Mention label in matplotlib plot based on categorical class

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