Re: [Matplotlib-users] wxList and FigureCanvasWx

[John H. <jdh...@ac...>]

>>>>> "John" == John Hunter <jdh...@ac...> writes:

    John> The example is included below.  I'll add it to the examples
    John> dir for people who want to work directly with the Agg canvas
    John> 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)
fig.add_axis(ax)
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

# get the figure dimensions for creating bitmaps or numeric arrays,
# 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()