CODEWITHSUNDEEP
pythonmatplotlib
Leo Liao
Leo Liao

Reputation: 35

Multi-lines(with different markers) in legend

I want to show multi-lines with the same label but different markers in legend.

The graph I want to plot is similar to this:

plot

But there's no marker setting in LineCollection, I expect each line has different marker.

Any idea? Thank you.

Upvotes: 2

Views: 902

Answers (1)

ImportanceOfBeingErnest
ImportanceOfBeingErnest

Reputation: 339102

The picture you show stems from the legend demo. Similar to what is done there you may subclass a legend handler to create a legend of choice.

Here one may use a HandlerTuple such that one can directly supply the complete list of lines in the legend.

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.legend_handler import HandlerTuple


class HandlerLinesVertical(HandlerTuple):
    def create_artists(self, legend, orig_handle,
                   xdescent, ydescent, width, height, fontsize,
                   trans):
        ndivide = len(orig_handle)
        a_list = []
        for i, handle in enumerate(orig_handle):
            y = (height / float(ndivide)) * i -ydescent
            line = plt.Line2D(np.array([0,1])*width, [-y,-y])
            line.update_from(handle)
            line.set_marker(None)
            point = plt.Line2D(np.array([.5])*width, [-y])
            point.update_from(handle)
            for artist in [line, point]:
                artist.set_transform(trans)
            a_list.extend([line,point])
        return a_list

x = np.linspace(0, 5, 15)

fig, ax = plt.subplots()

markers = ["o", "s", "d", "+", "*"]
lines = []
for i, marker in zip(range(5),markers):
    line, = ax.plot(x, np.sin(x) - .1 * i, marker=marker)
    lines.append(line)

ax.legend([tuple(lines)], ["legend entry"], handler_map={tuple:HandlerLinesVertical()},
           handleheight=8 )
plt.show()

enter image description here

Upvotes: 2

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