setting a legend matching the colours in pyplot.scatter

user_1878788 0
Viewed 3489

Suppose my data is organized in the following way:

x_values = [6.2, 3.6, 7.3, 3.2, 2.7]
y_values = [1.5, 3.2, 5.4, 3.1, 2.8]
colours = [1, 1, 0, 1, -1]
labels = ["a", "a", "b", "a", "c"]

I want to make a scatterplot with this:

axis = plt.gca()
axis.scatter(x_values, y_values, c=colours)

I want a legend with 3 categories: "a", "b" and "c".

Can I use the labels list to make this legend, given that the categories in this list match the order of the points in the colours list?

Do I need to run the scatter command separately for each category?

matplotlib python
3 Answers

Just a remark, not exactly answering the question:

If use "seaborn" it would be EXACTLY ONE LINE:

import seaborn as sns 
x_values = [6.2, 3.6, 7.3, 3.2, 2.7]
y_values = [1.5, 3.2, 5.4, 3.1, 2.8]
#colors = [1, 1, 0, 1, -1]
labels = ["a", "a", "b", "a", "c"]
ax = sns.scatterplot(x=x_values, y=y_values, hue=labels)

enter image description here

PS

But the question is about matplotlib, so. We have answers above, also one might look at: https://matplotlib.org/3.1.1/gallery/lines_bars_and_markers/scatter_with_legend.html Subsection: "Automated legend creation".

However I feel not easy to modify those examples to what you need.

user_6253960
Related