# wxList and FigureCanvasWx

RE: [Matplotlib-users] wxList and FigureCanvasWx
John –

Thanks for the help! Your example cleared up a lot of problems. I’ll send you a screen dump of what I’m doing when it’s ready.

Dave Engelsma

Lacks Wheel Trim Systems

···

-----Original Message-----

From: John Hunter [mailto:jdhunter@…4…]

Sent: Monday, May 03, 2004 4:52 PM

To: Engelsma, Dave

Subject: Re: [Matplotlib-users] wxList and FigureCanvasWx

> The example is included below.  I'll add it to the examples

> dir for people who want to work directly with the Agg canvas

> and renderer.


oops, left out a critical line - adding the axes to the figure.

Here is a modified example, which also demonstrates initializing a

Numeric array from the string and passing the image off to PIL…

“”"

This is an example that shows you how to work directly with the agg

figure canvas to create a figure using the pythonic API.

In this example, the contents of the agg canvas are extracted to a

string, which can in turn be passed off to PIL or put in a numeric

array

“”"

#!/usr/bin/env python

from matplotlib.backends.backend_agg import FigureCanvasAgg

from matplotlib.figure import Figure

from matplotlib.axes import Subplot

from matplotlib.mlab import normpdf

from matplotlib.numerix import randn

fig = Figure(figsize=(5,4), dpi=100)

ax = Subplot(fig, 111)

canvas = FigureCanvasAgg(fig)

mu, sigma = 100, 15

x = mu + sigma*randn(10000)

# the histogram of the data

n, bins, patches = ax.hist(x, 50, normed=1)

# add a ‘best fit’ line

y = normpdf( bins, mu, sigma)

line, = ax.plot(bins, y, ‘r–’)

line.set_linewidth(1)

ax.set_xlabel(‘Smarts’)

ax.set_ylabel(‘Probability’)

ax.set_title(r’\rm{Histogram of IQ: }\mu=100, \sigma=15')

ax.set_xlim( (40, 160))

ax.set_ylim( (0, 0.03))

canvas.draw()

s = canvas.tostring_rgb() # save this and convert to bitmap as needed

# etc.

l,b,w,h = fig.bbox.get_bounds()

w, h = int(w), int(h)

if 0:

# convert to a Numeric array

X = fromstring(s, UInt8)

X.shape = h, w, 3


if 0:

# pass off to PIL

import Image

im = Image.fromstring( "RGB", (w,h), s)

im.show()