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That does the trick!  Thanks Eric.

==========

The 2nd Law of Thermodynamics... If you think things are a mess now, JUST
WAIT!


On Sat, Sep 20, 2008 at 12:47 PM, Eric Firing <ef...@ha...> wrote:

> charles reid wrote:
>
>> Hi there -
>>
>> I'm wondering if there is a way to do this, since I haven't found anything
>> online or in the mailing list archives that covers it.  I'd like to draw a
>> line from inside the plot area to outside the plot area (see attached image
>> - the blue line is what I plot, but I'd like to know how to create something
>> like the red line, which goes beyond the axes of the plot).  I'm guessing I
>> would create an additional layer in the same figure, but make a layer
>> without axes.  However, I'm not exactly sure what I should do - add an
>> additional canvas?  a new renderer?  If you can point me to the right
>> documentation or give me some idea of how I should be doing this, I would
>> really appreciate it.
>>
>
> You can turn off the clipping to the axes box on a per-artist basis.
> Something like this:
>
> import matplotlib.pyplot as plt
> import numpy as np
> x = np.arange(10)
> y = np.ones_like(x)
> ll = plt.plot(x,y) # returns a sequence of line objects
> ll[0].set_clip_on(False)
> plt.axis([0,3,0,3])
> plt.show()
>
> Eric
>
>
>
>>
>> Charles
>>
>> ==========
>>
>> The 2nd Law of Thermodynamics... If you think things are a mess now, JUST
>> WAIT!
>>
>> ------------------------------------------------------------------------
>>
>>
>> ------------------------------------------------------------------------
>>
>> -------------------------------------------------------------------------
>> This SF.Net email is sponsored by the Moblin Your Move Developer's
>> challenge
>> Build the coolest Linux based applications with Moblin SDK & win great
>> prizes
>> Grand prize is a trip for two to an Open Source event anywhere in the
>> world
>> http://moblin-contest.org/redirect.php?banner_id=100&url=/
>>
>>
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> Matplotlib-users mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>>
>
>

charles reid wrote:
> Hi there -
> 
> I'm wondering if there is a way to do this, since I haven't found 
> anything online or in the mailing list archives that covers it.  I'd 
> like to draw a line from inside the plot area to outside the plot area 
> (see attached image - the blue line is what I plot, but I'd like to know 
> how to create something like the red line, which goes beyond the axes of 
> the plot).  I'm guessing I would create an additional layer in the same 
> figure, but make a layer without axes.  However, I'm not exactly sure 
> what I should do - add an additional canvas?  a new renderer?  If you 
> can point me to the right documentation or give me some idea of how I 
> should be doing this, I would really appreciate it.

You can turn off the clipping to the axes box on a per-artist basis. 
Something like this:

import matplotlib.pyplot as plt
import numpy as np
x = np.arange(10)
y = np.ones_like(x)
ll = plt.plot(x,y) # returns a sequence of line objects
ll[0].set_clip_on(False)
plt.axis([0,3,0,3])
plt.show()

Eric


> 
> 
> Charles
> 
> ==========
> 
> The 2nd Law of Thermodynamics... If you think things are a mess now, 
> JUST WAIT!
> 
> ------------------------------------------------------------------------
> 
> 
> ------------------------------------------------------------------------
> 
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
> Build the coolest Linux based applications with Moblin SDK & win great prizes
> Grand prize is a trip for two to an Open Source event anywhere in the world
> http://moblin-contest.org/redirect.php?banner_id=100&url=/
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users

Excellent!
That's was EXACTLY what I needed!
Thanks a lot Friedrich!

:)

2008/9/20 Friedrich Hagedorn <fri...@gm...>:
> On Sat, Sep 20, 2008 at 04:06:36PM +0200, Laurent Dufrechou wrote:
>> Hello all,
>> I'm trying to show to  a friend matplotlib features via pylab interface.
>> (thus to replace matlab/scilab)
>> I've a little problem while I'm trying to display plots into subplots here
>> under vista.
>> If I add a pylab.xlabel to the subplots they are masked by the underlying
>> subplot.
>> To workaround it I need to change the window size.
>> I used for myself add_axes([0.1,0.8,0.75,.15]) but that's not that easy.
>
> That's right (but sometimes I did the same :-)
>
>> Do I miss one important thing or must I go trought add_axes functions each
>> time I call pylab.subplot?
>
> Yes, you can adjust the space between the subplot with
>
>  subplots_adjust()
>
> Look at the docstring with
>
>  In [1]: subplots-adjust?
>
> in ipython shell. Try to see the difference between
>
>  figure()
>  subplot(211)
>  subplot(212)
>  show()
>
> and
>
>  figure()
>  subplots_adjust(hspace=0.4)  # standard: 0.2
>  subplot(211)
>  subplot(212)
>  show()
>
> By,
>
>  Friedrich
>

On Sat, Sep 20, 2008 at 04:06:36PM +0200, Laurent Dufrechou wrote:
> Hello all,
> I'm trying to show to  a friend matplotlib features via pylab interface.
> (thus to replace matlab/scilab)
> I've a little problem while I'm trying to display plots into subplots here
> under vista.
> If I add a pylab.xlabel to the subplots they are masked by the underlying
> subplot.
> To workaround it I need to change the window size.
> I used for myself add_axes([0.1,0.8,0.75,.15]) but that's not that easy.

That's right (but sometimes I did the same :-)

> Do I miss one important thing or must I go trought add_axes functions each
> time I call pylab.subplot?

Yes, you can adjust the space between the subplot with

  subplots_adjust()
  
Look at the docstring with

  In [1]: subplots-adjust?

in ipython shell. Try to see the difference between

  figure()
  subplot(211)
  subplot(212)
  show()

and

  figure()
  subplots_adjust(hspace=0.4)  # standard: 0.2
  subplot(211)
  subplot(212)
  show()

By,

  Friedrich

Hello all,
I'm trying to show to  a friend matplotlib features via pylab interface.
(thus to replace matlab/scilab)
I've a little problem while I'm trying to display plots into subplots here
under vista.
If I add a pylab.xlabel to the subplots they are masked by the underlying
subplot.
To workaround it I need to change the window size.
I used for myself add_axes([0.1,0.8,0.75,.15]) but that's not that easy.
Do I miss one important thing or must I go trought add_axes functions each
time I call pylab.subplot?

Thx for any idea!

Laurent

Try something like this:

import pylab as pl

head = ((0,    0,    10),
        (1,    0,    13),
        (2,    0,    11),
        (3,    0,    12),
        (1,    2,    11))

x, y, z = zip(*head)
xi, yi = pl.arange(0, 4, 0.1), pl.arange(0, 3, 0.1)
g = pl.griddata(x, y, z, xi, yi)
pl.scatter(x, y)
pl.contour(xi, yi, g)

Level values are automatically chosen in this example but you can
provide the number of values or a sequence of them.

Note that no extrapolation is done outside convex hull defined by input
data.

Goyo

El sáb, 20-09-2008 a las 11:13 +0200, Oz Nahum escribió:
> I'm trying again to understand how to plot scattered data from array into
>    contour graph.
>    I looked at
>    http://www.scipy.org/Cookbook/Matplotlib/Gridding_irregularly_spaced_data
>    and I understand I have to grid my data. However, in most samples the plot
>    is of a function.
>    Let's say I want to plot some geological data, suppose water table head, and
>    I have the following 3D aray
>                x     y    head
>    head =  ((0,    0,    10),
>                (1,    0,    13),
>                (2,    0,    11),
>                (3,    0,    12),
>                (1,    2,    11))
>    matplotlib has lot's of restrictions about how I can plot and interpolate
>    the data, which causes a lot of confusion in my side...
>    I'll be happy if someone could supply me a clue of how to plot contours of
>    data which comes in arrays or raster format and not an equation.
>    Thanks,
>    Oz
> 
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
> Build the coolest Linux based applications with Moblin SDK & win great prizes
> Grand prize is a trip for two to an Open Source event anywhere in the world
> http://moblin-contest.org/redirect.php?banner_id=100&url=/
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users

I'm trying again to understand how to plot scattered data from array into
   contour graph.
   I looked at
   http://www.scipy.org/Cookbook/Matplotlib/Gridding_irregularly_spaced_data
   and I understand I have to grid my data. However, in most samples the plot
   is of a function.
   Let's say I want to plot some geological data, suppose water table head, and
   I have the following 3D aray
               x     y    head
   head =  ((0,    0,    10),
               (1,    0,    13),
               (2,    0,    11),
               (3,    0,    12),
               (1,    2,    11))
   matplotlib has lot's of restrictions about how I can plot and interpolate
   the data, which causes a lot of confusion in my side...
   I'll be happy if someone could supply me a clue of how to plot contours of
   data which comes in arrays or raster format and not an equation.
   Thanks,
   Oz

jas...@cr... wrote:
> Eric Firing wrote:
>>>> Well, the easiest way is to build mpl from svn; a few minutes ago I 
>>>> added this capability to quiver, selectable with an "angles" kwarg.
> 
> Eric,
> 
> I tried just copying the quiver.py SVN version 6114 into my existing 
> matplotlib install and numpy 1.1.1.  When running my example posted 
> earlier with the angles='xy' keyword added to the quiver call, I get the 
> following error:

So do I.  I'll have to track down the bug.

Eric

> 
> In [10]: show()
> ---------------------------------------------------------------------------
> <type 'exceptions.ValueError'>            Traceback (most recent call last)
> 
> /usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py in 
> expose_event(self, widget, event)
>    331                 x, y, w, h = self.allocation
>    332                 self._pixmap_prepare (w, h)
> --> 333                 self._render_figure(self._pixmap, w, h)
>    334                 self._need_redraw = False
>    335
> 
> /usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtkagg.py 
> in _render_figure(self, pixmap, width, height)
>     73     def _render_figure(self, pixmap, width, height):
>     74         if DEBUG: print 'FigureCanvasGTKAgg.render_figure'
> ---> 75         FigureCanvasAgg.draw(self)
>     76         if DEBUG: print 'FigureCanvasGTKAgg.render_figure 
> pixmap', pixmap
>     77         #agg_to_gtk_drawable(pixmap, self.renderer._renderer, None)
> 
> /usr/lib/python2.5/site-packages/matplotlib/backends/backend_agg.py in 
> draw(self)
>    259
>    260         self.renderer = self.get_renderer()
> --> 261         self.figure.draw(self.renderer)
>    262
>    263     def get_renderer(self):
> 
> /usr/lib/python2.5/site-packages/matplotlib/figure.py in draw(self, 
> renderer)
>    757
>    758         # render the axes
> --> 759         for a in self.axes: a.draw(renderer)
>    760
>    761         # render the figure text
> 
> /usr/lib/python2.5/site-packages/matplotlib/axes.py in draw(self, 
> renderer, inframe)
>   1521
>   1522         for zorder, i, a in dsu:
> -> 1523             a.draw(renderer)
>   1524
>   1525         renderer.close_group('axes')
> 
> /usr/lib/python2.5/site-packages/matplotlib/quiver.py in draw(self, 
> renderer)
>    423         self._init()
>    424         if self._new_UV or self.angles == 'xy':
> --> 425             verts = self._make_verts(self.U, self.V)
>    426             self.set_verts(verts, closed=False)
>    427             self._new_UV = False
> 
> /usr/lib/python2.5/site-packages/matplotlib/quiver.py in 
> _make_verts(self, U, V)
>    483         else:
>    484             theta = ma.asarray(self.angles*np.pi/180.0).filled(0)
> --> 485         xy = (X+Y*1j) * np.exp(1j*theta)*self.width
>    486         xy = xy[:,:,np.newaxis]
>    487         XY = ma.concatenate((xy.real, xy.imag), axis=2)
> 
> /usr/lib/python2.5/site-packages/numpy/ma/core.py in __mul__(self, other)
>   1710     def __mul__(self, other):
>   1711         "Multiply other by self, and return a new masked array."
> -> 1712         return multiply(self, other)
>   1713     #
>   1714     def __div__(self, other):
> 
> /usr/lib/python2.5/site-packages/numpy/ma/core.py in __call__(self, a, 
> b, *args, **kwargs)
>    513         m = mask_or(getmask(a), getmask(b))
>    514         (d1, d2) = (get_data(a), get_data(b))
> --> 515         result = self.f(d1, d2, *args, 
> **kwargs).view(get_masked_subclass(a, b))
>    516         if result.size > 1:
>    517             if m is not nomask:
> 
> <type 'exceptions.ValueError'>: shape mismatch: objects cannot be 
> broadcast to a single shape
> 
> 
> 
> Do you know if this is caused by trying to use the new quiver.py in 
> 0.98.3?  Does my example before (copied below for convenience) work for 
> you?
> 
> from pylab import *
> 
> X,Y = meshgrid( arange(0,1,.2),arange(0,1,.2) )
> def yprime(x,y):
>    return 1
> 
> U,V = meshgrid([1]*len(X), [1]*len(Y))
> 
> figure()
> Q = quiver(X,Y,U, V, angles='xy')
> 
> # This is a solution to the differential equation y'=1, but it doesn't
> # look like it because the slopes do not respect the aspect ratio of
> # the plot.  What should happen is the arrows should point along the
> # line.
> plot([0,1],[0,1])
> 
> axis([0,1,0,0.5])
> 
> title("Slope Field for $dy/dx=1$")
> show()
> 
> 
> Thanks,
> 
> Jason
> 

Eric Firing wrote:
>>> Well, the easiest way is to build mpl from svn; a few minutes ago I 
>>> added this capability to quiver, selectable with an "angles" kwarg.

Eric,

I tried just copying the quiver.py SVN version 6114 into my existing 
matplotlib install and numpy 1.1.1.  When running my example posted 
earlier with the angles='xy' keyword added to the quiver call, I get the 
following error:

In [10]: show()
---------------------------------------------------------------------------
<type 'exceptions.ValueError'>            Traceback (most recent call last)

/usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py in 
expose_event(self, widget, event)
    331                 x, y, w, h = self.allocation
    332                 self._pixmap_prepare (w, h)
--> 333                 self._render_figure(self._pixmap, w, h)
    334                 self._need_redraw = False
    335

/usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtkagg.py 
in _render_figure(self, pixmap, width, height)
     73     def _render_figure(self, pixmap, width, height):
     74         if DEBUG: print 'FigureCanvasGTKAgg.render_figure'
---> 75         FigureCanvasAgg.draw(self)
     76         if DEBUG: print 'FigureCanvasGTKAgg.render_figure 
pixmap', pixmap
     77         #agg_to_gtk_drawable(pixmap, self.renderer._renderer, None)

/usr/lib/python2.5/site-packages/matplotlib/backends/backend_agg.py in 
draw(self)
    259
    260         self.renderer = self.get_renderer()
--> 261         self.figure.draw(self.renderer)
    262
    263     def get_renderer(self):

/usr/lib/python2.5/site-packages/matplotlib/figure.py in draw(self, 
renderer)
    757
    758         # render the axes
--> 759         for a in self.axes: a.draw(renderer)
    760
    761         # render the figure text

/usr/lib/python2.5/site-packages/matplotlib/axes.py in draw(self, 
renderer, inframe)
   1521
   1522         for zorder, i, a in dsu:
-> 1523             a.draw(renderer)
   1524
   1525         renderer.close_group('axes')

/usr/lib/python2.5/site-packages/matplotlib/quiver.py in draw(self, 
renderer)
    423         self._init()
    424         if self._new_UV or self.angles == 'xy':
--> 425             verts = self._make_verts(self.U, self.V)
    426             self.set_verts(verts, closed=False)
    427             self._new_UV = False

/usr/lib/python2.5/site-packages/matplotlib/quiver.py in 
_make_verts(self, U, V)
    483         else:
    484             theta = ma.asarray(self.angles*np.pi/180.0).filled(0)
--> 485         xy = (X+Y*1j) * np.exp(1j*theta)*self.width
    486         xy = xy[:,:,np.newaxis]
    487         XY = ma.concatenate((xy.real, xy.imag), axis=2)

/usr/lib/python2.5/site-packages/numpy/ma/core.py in __mul__(self, other)
   1710     def __mul__(self, other):
   1711         "Multiply other by self, and return a new masked array."
-> 1712         return multiply(self, other)
   1713     #
   1714     def __div__(self, other):

/usr/lib/python2.5/site-packages/numpy/ma/core.py in __call__(self, a, 
b, *args, **kwargs)
    513         m = mask_or(getmask(a), getmask(b))
    514         (d1, d2) = (get_data(a), get_data(b))
--> 515         result = self.f(d1, d2, *args, 
**kwargs).view(get_masked_subclass(a, b))
    516         if result.size > 1:
    517             if m is not nomask:

<type 'exceptions.ValueError'>: shape mismatch: objects cannot be 
broadcast to a single shape



Do you know if this is caused by trying to use the new quiver.py in 
0.98.3?  Does my example before (copied below for convenience) work for you?

from pylab import *

X,Y = meshgrid( arange(0,1,.2),arange(0,1,.2) )
def yprime(x,y):
    return 1

U,V = meshgrid([1]*len(X), [1]*len(Y))

figure()
Q = quiver(X,Y,U, V, angles='xy')

# This is a solution to the differential equation y'=1, but it doesn't
# look like it because the slopes do not respect the aspect ratio of
# the plot.  What should happen is the arrows should point along the
# line.
plot([0,1],[0,1])

axis([0,1,0,0.5])

title("Slope Field for $dy/dx=1$")
show()


Thanks,

Jason

jas...@cr... wrote:
> Eric Firing wrote:
>>>> Well, the easiest way is to build mpl from svn; a few minutes ago I 
>>>> added this capability to quiver, selectable with an "angles" kwarg.
> 
> Eric,
> 
> I tried just copying the quiver.py SVN version 6114 into my existing 
> matplotlib install and numpy 1.1.1.  When running my example posted 
> earlier with the angles='xy' keyword added to the quiver call, I get the 
> following error:

Fixed in svn 6115.  Sorry I didn't catch it initially.  It was a pretty 
basic bug.

Eric

> 
> In [10]: show()
> ---------------------------------------------------------------------------
> <type 'exceptions.ValueError'>            Traceback (most recent call last)
> 
> /usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtk.py in 
> expose_event(self, widget, event)
>    331                 x, y, w, h = self.allocation
>    332                 self._pixmap_prepare (w, h)
> --> 333                 self._render_figure(self._pixmap, w, h)
>    334                 self._need_redraw = False
>    335
> 
> /usr/lib/python2.5/site-packages/matplotlib/backends/backend_gtkagg.py 
> in _render_figure(self, pixmap, width, height)
>     73     def _render_figure(self, pixmap, width, height):
>     74         if DEBUG: print 'FigureCanvasGTKAgg.render_figure'
> ---> 75         FigureCanvasAgg.draw(self)
>     76         if DEBUG: print 'FigureCanvasGTKAgg.render_figure 
> pixmap', pixmap
>     77         #agg_to_gtk_drawable(pixmap, self.renderer._renderer, None)
> 
> /usr/lib/python2.5/site-packages/matplotlib/backends/backend_agg.py in 
> draw(self)
>    259
>    260         self.renderer = self.get_renderer()
> --> 261         self.figure.draw(self.renderer)
>    262
>    263     def get_renderer(self):
> 
> /usr/lib/python2.5/site-packages/matplotlib/figure.py in draw(self, 
> renderer)
>    757
>    758         # render the axes
> --> 759         for a in self.axes: a.draw(renderer)
>    760
>    761         # render the figure text
> 
> /usr/lib/python2.5/site-packages/matplotlib/axes.py in draw(self, 
> renderer, inframe)
>   1521
>   1522         for zorder, i, a in dsu:
> -> 1523             a.draw(renderer)
>   1524
>   1525         renderer.close_group('axes')
> 
> /usr/lib/python2.5/site-packages/matplotlib/quiver.py in draw(self, 
> renderer)
>    423         self._init()
>    424         if self._new_UV or self.angles == 'xy':
> --> 425             verts = self._make_verts(self.U, self.V)
>    426             self.set_verts(verts, closed=False)
>    427             self._new_UV = False
> 
> /usr/lib/python2.5/site-packages/matplotlib/quiver.py in 
> _make_verts(self, U, V)
>    483         else:
>    484             theta = ma.asarray(self.angles*np.pi/180.0).filled(0)
> --> 485         xy = (X+Y*1j) * np.exp(1j*theta)*self.width
>    486         xy = xy[:,:,np.newaxis]
>    487         XY = ma.concatenate((xy.real, xy.imag), axis=2)
> 
> /usr/lib/python2.5/site-packages/numpy/ma/core.py in __mul__(self, other)
>   1710     def __mul__(self, other):
>   1711         "Multiply other by self, and return a new masked array."
> -> 1712         return multiply(self, other)
>   1713     #
>   1714     def __div__(self, other):
> 
> /usr/lib/python2.5/site-packages/numpy/ma/core.py in __call__(self, a, 
> b, *args, **kwargs)
>    513         m = mask_or(getmask(a), getmask(b))
>    514         (d1, d2) = (get_data(a), get_data(b))
> --> 515         result = self.f(d1, d2, *args, 
> **kwargs).view(get_masked_subclass(a, b))
>    516         if result.size > 1:
>    517             if m is not nomask:
> 
> <type 'exceptions.ValueError'>: shape mismatch: objects cannot be 
> broadcast to a single shape
> 
> 
> 
> Do you know if this is caused by trying to use the new quiver.py in 
> 0.98.3?  Does my example before (copied below for convenience) work for 
> you?
> 
> from pylab import *
> 
> X,Y = meshgrid( arange(0,1,.2),arange(0,1,.2) )
> def yprime(x,y):
>    return 1
> 
> U,V = meshgrid([1]*len(X), [1]*len(Y))
> 
> figure()
> Q = quiver(X,Y,U, V, angles='xy')
> 
> # This is a solution to the differential equation y'=1, but it doesn't
> # look like it because the slopes do not respect the aspect ratio of
> # the plot.  What should happen is the arrows should point along the
> # line.
> plot([0,1],[0,1])
> 
> axis([0,1,0,0.5])
> 
> title("Slope Field for $dy/dx=1$")
> show()
> 
> 
> Thanks,
> 
> Jason
>