Re: [Matplotlib-users] [Fwd: Re: Pie chart is "stretched"]

On 6/4/07, Erik Wickstrom <er...@er...> wrote:

I didn't see Eric answer your "oblong" part of the question.  To make
it circular, use aspect='equal'

ax = fig.add_subplot(111, aspect='equal')

> -Can I give it more of a 3d look?  Like the pie charts in MS Word?

enable shadow=True, eg

pie(...., shadow=True)

> -How can I reduce the size of the canvas behind the chart?  There is a
> lot of empty whitespace and I need to tighten up the margins as the
> graph will be displayed inline on an html page...

Set your own axes dimensions, just make sure it is square

fig = figure(figsize=(6,6))
ax = fig.add_axes([0.05, 0.05, 0.9, 0.9], aspect='equal')

> -for the colors, do I use numbers to customize the colors, or do I
> have to use colors from a built in pallet?

You can do it either way, but if you want your colors to reflect the
magnitude of the percentage for a given slice, you will need to use a
colormap.   See below

> -lastly - is it possible to print the labels inside each slice of the
> chart, instead of outside?

Unfortunately not, but there should be.  I just added a new keyword
arg "labeldistance" which is a fraction of the radius at which to
print the label (default 1.1).  Changes are in svn.


import matplotlib.cm as cm

from pylab import figure, show

# make a square figure and axes
fig = figure(figsize=(8,8))
ax = fig.add_axes([0.05, 0.05, 0.90, 0.90], aspect='equal')

labels = 'Frogs', 'Hogs', 'Dogs', 'Logs'
fracs = [15,30,45, 10]

jet = cm.get_cmap('RdYlGn', 256)
scalarmap = cm.ScalarMappable(cmap=jet)
scalarmap.set_clim(0, 100)

colors = [scalarmap.to_rgba(frac) for frac in fracs]


ax.pie(fracs, labels=labels, colors=colors,
       pctdistance=0.4, labeldistance=0.9,
       autopct='%d%%', shadow=True)

show()