Exploding Bar Chart

README.md

#Why

I haven't seen any visualizations of "Exploding Bar Charts" using matplotlib like the this one:

So I put together some very quick code to show how it could be done

#WIP

This is very much a WIP, right now the values of the expansion lines are hard coded, but I'm attempting to extract the Rectangle attributes to be choose which data point you are "exploding."

exploding_bar.py

import pandas
import numpy
import matplotlib.pyplot as plt

def run_fun():
    numpy.random.seed(seed = 69)
    dat = pandas.DataFrame(numpy.random.randn(5, 2), 
                           index = [letter for letter in 'abcde'],
                           columns = [0, 1])

    color_a = ["#7F8392", "#B08B47", "#52A479", "#C6778A", "#CF7B5E"]
    color_b = ["#829554", "#A78071", "#AD8AB2", "#679486", "#65A1BC"]

    fig = plt.figure()
    ax = plt.subplot2grid((1,1), (0,0))

    stacked_barchart(ax, 0, dat.loc[:, 0], color_a)
    stacked_barchart(ax, 1, dat.loc[:, 1], color_b)
    ax.plot([.25, .75], [0., 2.2], color = '#353535', ls = '--')
    ax.plot([.25, .75], [-1.6, -1.2], color = '#353535', ls = '--')

def stacked_barchart(ax, tick, series, colors):
    neg_sum = series[series < 0].sum()
    pos_sum = 0.
    for i, val in enumerate(series):
        if val < 0:
            neg_sum -= val
            ax.bar(tick, val, bottom = neg_sum, color = colors[i],
                   align = 'center', width = 0.5, 
                   lw = .25, label = series.index[i])
        else:
            ax.bar(tick, val, bottom = pos_sum, align = 'center',
                   width = 0.5, color = colors[i], 
                   label = series.index[i], lw = .25)
            pos_sum += val
    return ax

Results.md

#Results

Running the code you should get an image that looks like this