python-3.xmatplotlibsankey-diagram

Editing Python Matplotlib Sankey (removing values, align texts..)

I'm new to the Sankey diagram function in Matplotlib and I hope someone is able to help me with some things, since I cannot figure it out it seems.

First of all: I used the following example to understand how to create a Sankey diagram: https://flothesof.github.io/sankey-tutorial-matplotlib.html

This is the Sankey diagram:

enter image description here

Now there a few things that I need to change, two of which I don't know how.

Hope someone can help.

Solution

  • The .text field of each diagram contains its central label as a Text object. The .texts is a list of the Text objects for each of the entering/leaving arrows. You can check the string to know which text it is about, and change properties such as bold or the xy-position.

    As a Sankey diagram is quite complex, fine-tuning the positions can happen once the diagram is created. A simple approach can be to add additional newlines in the strings.

    import matplotlib.pyplot as plt
from matplotlib.sankey import Sankey

fig, ax = plt.subplots(figsize=(8, 12))
ax.set_xticks([])
ax.set_yticks([])
ax.set_title("My funnel")
ax.set_axis_off()
number = [round(12345 * 0.6 ** i) for i in range(6)]
labels = ["\n\n\n\n\n\n\nTotal joined", "\n\n\n\nFirst", "\n\nSecond", "\nThird", "\nFourth", "\n\nReached final"]

sankey = Sankey(ax=ax, scale=0.0015, offset=0.3)
for input_number, output_number, label in zip(number[:-1], number[1:], labels):
    this_index = len(sankey.diagrams)
    prior = this_index - 1 if this_index > 0 else None
    pathlengths = [0, 0, 2 if this_index != 4 else 10]
    exitlabel = labels[-1] if this_index == 4 else None
    sankey.add(flows=[input_number, -output_number, output_number - input_number],
               orientations=[0, 0, 1],
               patchlabel=label,
               labels=['', exitlabel, 'quit'],
               prior=prior,
               connect=(1, 0),
               pathlengths=pathlengths,
               trunklength=10.,
               rotation=-90,
               facecolor=plt.cm.spring((this_index + 1) / 5))
diagrams = sankey.finish()
for diagram in diagrams:
    diagram.text.set_fontweight('bold')
    diagram.text.set_fontsize('10')
    for text in diagram.texts:
        text.set_fontsize('10')
        label = text.get_text()  # can be normal label, "quit", a number or empty
        if len(label) > 0:
            if label[0].isdigit():
                text.set_visible(False)
            elif label.startswith('quit'):
                xy = text.get_position()
                text.set_position((xy[0] + 2, xy[1]))
            else:
                text.set_fontweight('bold')
plt.ylim(ymin=plt.ylim()[0] * 1.05)
plt.show()

    example plot