Re: [Matplotlib-users] tornado chart

[Tony Yu <ts...@gm...>]

On Thu, Jun 21, 2012 at 6:42 PM, Alan G Isaac <ala...@gm...> wrote:

> I never thought it would happen, but the
> Matplotlib Gallery has for once failed me:
> http://matplotlib.sourceforge.net/gallery.html
>
> I was looking for an example of creating a nice
> tornado chart:
>
> http://code.enthought.com/projects/chaco/docs/html/user_manual/tutorial_1.html
> http://www.tushar-mehta.com/excel/software/tornado/
> http://www.juiceanalytics.com/writing/recreating-ny-times-cancer-graph/
>
> A basic version will do, say along the lines of
> the Chaco example.
>
> Thanks for any leads,
> Alan Isaac
>
>
Hi Alan,

Here's an example based off the horizontal bar charts in the gallery. There
may be a better way to align the y-tick labels (the example manually tweaks
the x-offset), but I don't know how to do it off the top of my head.
Alternatively, you could put the ticks on the left and squish the space
between subplots (using `subplots_adjust(wspace=0)` but then you run into
the issue of overlapping x-tick labels.

Hope that helps,
-Tony

# tornado chart example
import numpy as np
import matplotlib.pyplot as plt


people = ('Tom', 'Dick', 'Harry', 'Slim', 'Jim')
num_people = len(people)

time_spent = np.random.uniform(low=5, high=100, size=num_people)
proficiency = np.abs(time_spent / 12. + np.random.normal(size=num_people))
pos = np.arange(num_people) + .5    # bars centered on the y axis

fig, (ax_left, ax_right) = plt.subplots(ncols=2)
ax_left.barh(pos, time_spent, align='center', facecolor='cornflowerblue')
ax_left.set_yticks([])
ax_left.set_xlabel('Hours spent')
ax_left.invert_xaxis()

ax_right.barh(pos, proficiency, align='center', facecolor='lemonchiffon')
ax_right.set_yticks(pos)
# x moves tick labels relative to left edge of axes in axes units
ax_right.set_yticklabels(people, ha='center', x=-0.08)
ax_right.set_xlabel('Proficiency')

plt.suptitle('Learning Python')

plt.show()