CODEWITHSUNDEEP
pythonmatplotlibannotationscursormplcursors
gil
gil

Reputation: 13

Labels for multiple data sets on the same graph using mplcursors

I have two sets of data that I'm graphing on the same plot using matplotlib. I'm using mplcursors to annotate each point using a label array. Unfortunately mplcursors uses the first five labels for both data sets. My question is how do I get the second data set to have it's own custom labels?

I realize for this simple example I could merge the data, but I can't for the project I'm working on.

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

x = np.array([0, 1, 2, 3, 4])
y = np.array([1, 2, 3, 4, 5])
y2 = np.array([2, 3, 4, 5, 6])

fig, ax = plt.subplots()
ax.plot(x, y, "ro")
ax.plot(x, y2, 'bx')

labels = ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j"]

mplcursors.cursor(ax, hover=True).connect(
    "add", lambda sel: sel.annotation.set_text(labels[sel.target.index]))
plt.show()

Upvotes: 1

Views: 1453

Answers (2)

ImportanceOfBeingErnest
ImportanceOfBeingErnest

Reputation: 339250

My comment about using a dictionary would look like this:

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

x = np.array([0, 1, 2, 3, 4])
y = np.array([1, 2, 3, 4, 5])
y2 = np.array([2, 3, 4, 5, 6])

fig, ax = plt.subplots()
line1, = ax.plot(x, y, "ro")
line2, = ax.plot(x, y2, 'bx')

labels1 = ["a", "b", "c", "d", "e"]
labels2 = ["f", "g", "h", "i", "j"]

d = dict(zip([line1, line2], [labels1, labels2]))

mplcursors.cursor(ax, hover=True).connect(
    "add", lambda sel: sel.annotation.set_text(d[sel.artist][sel.target.index]))

plt.show()

Upvotes: 3

gil
gil

Reputation: 13

Thanks to Ernest I was able to get a crude example working. I set the labels for each plot to be "one" and "two" respectively. Then when hovering over a point compare the artist name to the label using:

sel.artist.get_label()

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

x = np.array([0, 1, 2, 3, 4])
y = np.array([1, 2, 3, 4, 5])
y2 = np.array([2, 3, 4, 5, 6])

fig, ax = plt.subplots()
ax.plot(x, y, "ro", label="one")
ax.plot(x, y2, 'bx', label="two")

labels = ["a", "b", "c", "d", "e"]
labels2 = ["f", "g", "h", "i", "j"]

c1 = mplcursors.cursor(ax, hover=True)
@c1.connect("add")
def add(sel):
    if sel.artist.get_label() == "one":
        sel.annotation.set_text(labels[sel.target.index])
    elif sel.artist.get_label() == "two":
        sel.annotation.set_text(labels2[sel.target.index])

plt.show()

Upvotes: 0

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