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Hi Jae-Joon
On Mon, Jun 22, 2009 at 21:14, Jae-Joon Lee<lee...@gm...> wrote:
> Without actual code, it is difficult to figure out what the real problem is.
sorry I didn't attach a complete example but I would have to strip down a lot :)
> Anyhow, did you check the below animation example?
>
> http://matplotlib.sourceforge.net/examples/animation/animation_blit_gtk.html
yes, but I didn't have the illumination; until now :)
> In the example, the grid is static (i.e., not animated). If what you
that's perfect, I do not want it to be anymated.
> want is to have the grid animated, then an explicit draw_artist call
> is required (note that grid is drawn by axis).
yeah, I want it to be only on Y (only horizonatal lines).
The solution is:
 self.ax = self.fig.add_subplot(111)
...
 self.ax.grid(True)
 self.canvas.draw() # <-- this was missing
 self.bg = self.canvas.copy_from_bbox(self.ax.bbox)
adding an explicit draw() call let the grid() be drawn and then the
result is what's expected.
Thanks a lot!
Cheers,
-- 
Sandro Tosi (aka morph, morpheus, matrixhasu)
My website: http://matrixhasu.altervista.org/
Me at Debian: http://wiki.debian.org/SandroTosi

Without actual code, it is difficult to figure out what the real problem is.
Anyhow, did you check the below animation example?
http://matplotlib.sourceforge.net/examples/animation/animation_blit_gtk.html
In the example, the grid is static (i.e., not animated). If what you
want is to have the grid animated, then an explicit draw_artist call
is required (note that grid is drawn by axis).
Regards,
-JJ
On Sun, Jun 21, 2009 at 11:54 AM, Sandro Tosi<mat...@gm...> wrote:
> Hello,
> I'm using blit to animate my plot, and I'd like to add a grid on it
> but I failed at it.
>
> What I do is:
>
> 1. prepare Figure, Axes, etc without plotting anything
> 2. save teh background with
>   self.bg = self.canvas.copy_from_bbox(self.ax.bbox)
>
> (on graph update)
>
> 3. restore background with
>   self.canvas.restore_region(self.bg)
> 4. <line>.set_ydata(...)
> 5. self.ax.draw_artist(self.<line>)
> 6. self.canvas.blit(self.ax.bbox)
>
> Now, I tried to place a "self.ax.grid(True)" in almost every possible
> position, but never a grid came out :(
>
> What is the right approach to solve it? Thanks in advance
>
> Regards,
> --
> Sandro Tosi (aka morph, morpheus, matrixhasu)
> My website: http://matrixhasu.altervista.org/
> Me at Debian: http://wiki.debian.org/SandroTosi
>
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Tony,
My understanding is that (which might be wrong) drawing collections
involves (at least) 2 transforms. The first transform is (mostly) for
scaling, and the second transform is for offset. And this seems to be
true for PolygonCollection (which scatter creates) as far as I can
see.
set_transform() method sets the transform for scaling, which means
that (0,0) should transform to (0,0). Otherwise the polygon is not
drawn where you intended.
And, obviously transData does NOT, which I think is the root of the problem.
Unfortunately, the current PolygonCollection class does not seem to
have any support for what you want. On the other hand, it seems that
EllipseCollection lets you specify the ellipse size in data
coordinate.
The easiest solution I can think of is doing some monkey patching.
import matplotlib.pyplot as plt
import matplotlib.transforms as transforms
import numpy as np
fig = plt.figure()
ax = fig.add_subplot(111)
x = [0.25, 0.75, 0.25, 0.75]
y = [0.25, 0.25, 0.75, 0.75]
r = 0.1 * np.ones(4)
col = plt.scatter(x, y, np.pi*r**2)
from matplotlib.collections import RegularPolyCollection
class RegularPolyCollection2(RegularPolyCollection):
 def get_transform(self):
 ax = self.axes
 sc_x = ax.bbox.width / ax.viewLim.width
 sc_y = ax.bbox.height / ax.viewLim.height
 return transforms.Affine2D().scale(sc_x, sc_y)
col.__class__ = RegularPolyCollection2
plt.axis('equal')
plt.show()
Alternatively, you may modify your code to use EllipseCollection (if
what you want are just cricles).
I hope this solution fits your need.
Regards,
-JJ
On Thu, Jun 18, 2009 at 7:24 PM, Tony S Yu<to...@mi...> wrote:
> I'd like to plot a collection and scale the size of the collection
> elements in relation to the data. My guess is that I need to use the
> data transformation (ax.transData) since I would like the size of the
> collection elements altered when zooming in/out.
>
> Unfortunately, my attempt has led to weird results: the collection
> offsets are shifted from the desired coordinates when using
> ax.transData. Weirder still: the collection elements move *relative to
> the data coordinates* when panning the figure.
>
> I suspect that setting the collection transform to ax.transData is
> somehow applying some part of the transform twice. Does anyone know
> what I'm doing wrong here and how I can fix this?
>
> Thanks!
> -Tony
>
> Attached is a toy example of what I'm trying to do. The radii of the
> circles are plotted correctly, but notice the x, y coordinates don't
> match the circle centers in the plot. Also, try panning the plot and
> watch as the circles move relative to the tick marks.
>
>
> >>> import matplotlib.pyplot as plt
> >>> import matplotlib.transforms as transforms
> >>> import numpy as np
> >>> fig = plt.figure()
> >>> ax = fig.add_subplot(111)
> >>> x = [0.25, 0.75, 0.25, 0.75]
> >>> y = [0.25, 0.25, 0.75, 0.75]
> >>> r = 0.1 * np.ones(4)
> >>> col = plt.scatter(x, y, np.pi*r**2)
> >>> pts2pixels = transforms.Affine2D().scale(72.0/fig.dpi)
> >>> col.set_transform(pts2pixels + ax.transData)
> >>> plt.axis('equal')
> >>> plt.show()
>
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Anyone else have ideas on how to display large images?
Thanks,
Adam
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Hi everybody,
I have some probleme with Matplot/numpy !
I'm using matplot v0.91.2 and I'm trying to get the hist function working !!
I'm using the sample code of matplot:
----------------------------------------------------------
#!/usr/bin/env python
import numpy as np
import matplotlib.mlab as mlab
import matplotlib.pyplot as plt
mu, sigma = 100, 15
x = mu + sigma*np.random.randn(10000)
# the histogram of the data
n, bins, patches = plt.hist(x, 50, normed=1, facecolor='green', alpha=0.75)
print len(n)
print len(bins)
print n
print bins
# add a 'best fit' line
y = mlab.normpdf( bins, mu, sigma)
l = plt.plot(bins, y, 'r--', linewidth=1)
plt.xlabel('Smarts')
plt.ylabel('Probability')
plt.title(r'$\mathrm{Histogram\ of\ IQ:}\ \mu=100,\ \sigma=15$')
plt.axis([40, 160, 0, 0.03])
plt.grid(True)
plt.show()
------------------------------------------------------------
With the same matplot lib but a different version of numpy I get 2 different
number of bins !!! How is that possible ???
using the 1.0.4 version of numpy, I get len(n) = 50 and len(bins) = 50 ...
what sounds pretty right to me !! but using the version 1.2.1 (the last one
I guess) I got len(n) = 50 and len(bins) = 51 What looks weird, doesn't it
???
do you guys have an explanation ??
Anybody faced the same problem ?
thx, Jerome
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On Sun, Jun 21, 2009 at 4:42 PM, Thomas
Robitaille<tho...@gm...> wrote:
> Hi Jae-Joon,
>
> Thanks for the quick fix! Just looked in the svn browser, and noticed you
> changed line 5290 of axes.py to
>
> 'o' : (0,0,3),
>
> Should this not be
>
> 'o' : (0,3,0),
>
> ?
No, somehow the meaning of each item is different there. The last item
is the symbol style, unlike the input parameter for scatter where the
second one is the symbol style. For example,
 's' : (4,math.pi/4.0,0), # square
Regards,
-JJ
>
> Thanks,
>
> Tom
>
> On Jun 21, 2009, at 2:59 PM, Jae-Joon Lee wrote:
>
>> Thanks for the report.
>> And, this turned out to be a bug. The symbol style code was simply
>> ignored when its value is 3.
>>
>> While the bug should now be fixed (both in the trunk and the maint.
>> branch), you may use marker style like (20,0,0) (or increase the first
>> number when symbol is large) for a workaround.
>>
>> Regards,
>>
>> -JJ
>>
>>
>> On Sun, Jun 21, 2009 at 1:09 PM, Thomas
>> Robitaille<tho...@gm...> wrote:
>>>
>>> Hi,
>>>
>>> I'm trying to use the scatter method, making use of the option to specify
>>> the marker as a tuple. From the documentation, it would seem that
>>> specifying
>>> marker=(0,3,0) should draw a circle. However, this is not the case. If
>>> you
>>> consider the following code:
>>>
>>> import matplotlib
>>> matplotlib.use('Agg')
>>> import matplotlib.pyplot as mpl
>>>
>>> fig = mpl.figure()
>>> ax = fig.add_subplot(111)
>>> #ax.scatter([x],[y],c='red',marker=(0,3,0.))
>>> ax.scatter([10.],[10.],c='red',marker=(3,3,0.))
>>> ax.scatter([11.],[10.],c='red',marker=(6,3,0.))
>>> ax.set_xlim(5.,15.)
>>> fig.savefig('scatter.png')
>>>
>>> The first ax.scatter causes an error, the second plots a triangle, and
>>> the
>>> third a hexagon. However, the documentation states that (a) setting the
>>> second element to '3' should plot a circle, and (b) the other arguments
>>> should be ignored, so the first ax.scatter should not cause an error.
>>>
>>> Is this a bug, or am I misunderstanding the documentation?
>>>
>>> Thanks,
>>>
>>> Thomas
>>> --
>>> View this message in context:
>>> http://www.nabble.com/possible-bug-with-scatter-tp24136534p24136534.html
>>> Sent from the matplotlib - users mailing list archive at Nabble.com.
>>>
>>>
>>>
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>
>