Circosplot: Add legend indicating the label and color of each group of nodes

• nxviz version:
• Python version:
• Operating System:

Description

I worked with this library for a project that I had. One of the things that I used and that may be of benefit for other users of the library is to add to a circosplot the legend with labels and color for each group of the nodes. Attached the code below of how to do this and that you @ericmjl may like to incorporate to the library.

What I Did

import matplotlib.pyplot as plt
import matplotlib.patches as mpatches
from matplotlib.colors import to_hex

# Get the label and color for each group used by nxviz
seen = set()
colors_group = [x for x in c.node_colors if not (x in seen or seen.add(x))] #Gets colors in RGBA
labels_group = sorted(list(set([c.graph.node[n][c.node_color] for n in c.nodes]))) #Gets group labels

# Create patchList to use as handle for plt.legend()
patchList = []
for color, label in zip(colors_group, labels_group):
    color = to_hex(color, keep_alpha=True) #Convert RGBA to HEX value
    data_key = mpatches.Patch(color=color, label=label)
    patchList.append(data_key)

# Set the labels with the custom patchList
plt.legend(handles=patchList,
           loc="lower center",
           title="Enterprise size",
           ncol=4, # 4 columns to spread the legends
           borderpad=1,
           bbox_to_anchor =(0.5, -0.05), # To move the legend box lower than the graph
           shadow=True,
           fancybox=True)

[walter-hernandez]

Since the feature has been added, I am going to close this issue

[walter-hernandez]

Hello @ericmjl

Code added:

• Added the argument “group_legend” for the user to indicate if it wants the graph to include the legend or not.
• Exposed the legend_handles in the case that the user wants to customized the legend

Included dummy examples in the directory "examples\circos"for:

• The default legend:

• How to customize the legend using the CircosPlot().legend_handles