alluvial_diagram

A python script for generating "alluvial" styled bipartite diagrams, using matplotlib and numpy

Getting Started

Copy alluvial.py to a directory on the path, and import alluvial as shown below.

Prerequisites

pip install -r requirements.txt

Setup

Place alluvial.py on path.

Example 1:

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

input_data = {'a': {'aa': 0.3, 'cc': 0.7,},
              'b': {'aa': 2, 'bb': 0.5,},
              'c': {'aa': 0.5, 'bb': 0.5, 'cc': 1.5,}}

ax = alluvial.plot(input_data)
fig = ax.get_figure()
fig.set_size_inches(5,5)
plt.show()

Example 2:

import alluvial
import matplotlib.pyplot as plt
from matplotlib import colormaps 
import numpy as np

# Generating the input_data:
seed=7
np.random.seed(seed)
def rand_letter(num): return chr(ord('A')+int(num*np.random.rand()))

input_data = [[rand_letter(15), rand_letter(5)*2] for _ in range(50)]

# Plotting:
cmap = colormaps['jet']
ax = alluvial.plot(
    input_data,  alpha=0.4, color_side=1, rand_seed=seed, figsize=(7,5),
    disp_width=True, wdisp_sep=' '*2, cmap=cmap, fontname='Monospace',
    labels=('Capitals', 'Double Capitals'), label_shift=2)
ax.set_title('Utility display', fontsize=14, fontname='Monospace')
plt.show()

Parameter overview

• Alternative input format - a list of tuples of structure:
  • input_data = [('a_item0', 'b_item0'), ('a_item0', 'b_item1') , ('a_item1', 'b_item0')]
• Parameters and default values:
  • alpha=0.5 - defines facecolor alpha for all veins
  • color_side=0 - vein colors determined by left side items (0) or right side items (1)
  • x_range=(0, 1) - changes the horizontal plot coordinates
  • res=20 - determines the number of points constituting the alluvial vein spline
  • h_gap_frac=0.03 - changes the horizontal gap between the labels, vein base rectangles, and veins
  • v_gap_frac=0.03 - changes the vertical gap between veins
  • colors=None - an optional list of matplotlib spec colors, len(colors) must be equal to the number of items on color_side
  • cmap=None - a matplotlib.colormaps specification for choosing random colors. if None, 'hsv' is used
  • rand_seed=1 - a seed for the random color generator, if None colors are chosen at random
  • a_sort, b_sort - lists defining plot order of items (both are None by default). if None, items are sorted by width
  • disp_width=False - if True, displays vein widths beside item labels
  • wdisp_sep=7*' ' - seperates width and item text if width is displayed
  • width_in=True - displays width between the item text and the graph, reversed order if False
  • labels=None - a tuple of form ('a_label', 'b_label'), if None side labels are not plotted
  • figsize=(10, 15), The figure size.
  • fontname='Monospace' The font of all figure text

License

This project is licensed under the Apache 2.0 License - see the LICENSE.md file for details

Acknowledgments

• Inspired by the alluvial diagram example given in the rawgraphs website.