Thread: [Matplotlib-users] Matplotlib or numpy bug?

Hi matplotlib users,

The script below produces weird arrows when using numpy 1.2.1 and
matplotlib trunk. When I reinstall numpy 1.2.0 instead it seems fine.
I use the Agg backend. I am not sure where to start in tracking the
bug down so I will just post the rather sparse information that I
have.

Please let me know if you need any further information from me.

Best regards,
Jesper

import math
import numpy.ma as ma
import pylab as p

a = ma.ones((10,10))
a[:2,:] = ma.masked
a[:,9:] = ma.masked
b = ma.array(-a)
nx, ny = a.shape

for i in range(nx):
  for j in range(ny):
    a[i,j] = a[i,j]*math.cos(i*j)
    b[i,j] = -b[i,j]*math.sin(i*j)

print a

p.quiver(a,b)
p.grid(True)
p.savefig('test1.png')

Jesper Larsen wrote:
> Hi matplotlib users,
> 
> The script below produces weird arrows when using numpy 1.2.1 and
> matplotlib trunk. When I reinstall numpy 1.2.0 instead it seems fine.
> I use the Agg backend. I am not sure where to start in tracking the
> bug down so I will just post the rather sparse information that I
> have.

It looks OK to me with mpl and numpy from svn.

Eric

> 
> Please let me know if you need any further information from me.
> 
> Best regards,
> Jesper
> 
> import math
> import numpy.ma as ma
> import pylab as p
> 
> a = ma.ones((10,10))
> a[:2,:] = ma.masked
> a[:,9:] = ma.masked
> b = ma.array(-a)
> nx, ny = a.shape
> 
> for i in range(nx):
>   for j in range(ny):
>     a[i,j] = a[i,j]*math.cos(i*j)
>     b[i,j] = -b[i,j]*math.sin(i*j)
> 
> print a
> 
> p.quiver(a,b)
> p.grid(True)
> p.savefig('test1.png')
> 
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Hi Eric and Mauro,

Thanks for your answers.

2008/11/27 Eric Firing <ef...@ha...>:
> It looks OK to me with mpl and numpy from svn.

I tried upgrading to numpy from svn as well. Unfortunately the problem
persists (I have attached a plot). I have seen the problem on two of
my Ubuntu machines. Maybe it is caused by my specific setup and
supporting libraries.

Since I have a working solution and it does not seem to affect others
(based on a survey of two:-) let us just leave the problem for now. If
someone else encounter it please let me know and I will try to dive a
bit into the issue. If the problem turns up again when I have a need
to upgrade numpy (which is probably when matplotlib requires me to) I
will also look into it.

Best regards,
Jesper

Hi Jesper,

confirming the problem over here, as well. both numpy and mpl from svn
(also on an Ubuntu 8.04 machine).

good luck,
Paul


Jesper Larsen, on 2008-11-27 02:10, wrote:
> Hi Eric and Mauro,
> 
> Thanks for your answers.
> 
> 2008/11/27 Eric Firing <ef...@ha...>:
>> It looks OK to me with mpl and numpy from svn.
> 
> I tried upgrading to numpy from svn as well. Unfortunately the problem
> persists (I have attached a plot). I have seen the problem on two of
> my Ubuntu machines. Maybe it is caused by my specific setup and
> supporting libraries.
> 
> Since I have a working solution and it does not seem to affect others
> (based on a survey of two:-) let us just leave the problem for now. If
> someone else encounter it please let me know and I will try to dive a
> bit into the issue. If the problem turns up again when I have a need
> to upgrade numpy (which is probably when matplotlib requires me to) I
> will also look into it.
> 
> Best regards,
> Jesper
> 
> 
> ------------------------------------------------------------------------
> 
> 
> ------------------------------------------------------------------------
> 
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> 
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Paul Ivanov wrote:
> Hi Jesper,
> 
> confirming the problem over here, as well. both numpy and mpl from svn
> (also on an Ubuntu 8.04 machine).

Just checking: did you do a clean build of numpy (deleting any old build 
directory) and then a clean build of mpl?  Distutils is not very smart 
about dependencies.

Eric

> 
> good luck,
> Paul
> 
> 
> Jesper Larsen, on 2008-11-27 02:10, wrote:
>> Hi Eric and Mauro,
>>
>> Thanks for your answers.
>>
>> 2008/11/27 Eric Firing <ef...@ha...>:
>>> It looks OK to me with mpl and numpy from svn.
>> I tried upgrading to numpy from svn as well. Unfortunately the problem
>> persists (I have attached a plot). I have seen the problem on two of
>> my Ubuntu machines. Maybe it is caused by my specific setup and
>> supporting libraries.
>>
>> Since I have a working solution and it does not seem to affect others
>> (based on a survey of two:-) let us just leave the problem for now. If
>> someone else encounter it please let me know and I will try to dive a
>> bit into the issue. If the problem turns up again when I have a need
>> to upgrade numpy (which is probably when matplotlib requires me to) I
>> will also look into it.
>>
>> Best regards,
>> Jesper
>>
>>
>> ------------------------------------------------------------------------
>>
>>
>> ------------------------------------------------------------------------
>>
>> -------------------------------------------------------------------------
>> 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
> 
> 
> -------------------------------------------------------------------------
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> Build the coolest Linux based applications with Moblin SDK & win great prizes
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Eric Firing, on 2008-11-28 17:55, wrote:
> Paul Ivanov wrote:
>> Hi Jesper,
>>
>> confirming the problem over here, as well. both numpy and mpl from svn
>> (also on an Ubuntu 8.04 machine).
> 
> Just checking: did you do a clean build of numpy (deleting any old build
> directory) and then a clean build of mpl?  Distutils is not very smart
> about dependencies.
> 
> Eric

Yeah, just checked again against numpy 1.3.0.dev6118 and mpl r6456 after
clearing everything.

Paul

> 
>>
>> good luck,
>> Paul
>>
>>
>> Jesper Larsen, on 2008-11-27 02:10, wrote:
>>> Hi Eric and Mauro,
>>>
>>> Thanks for your answers.
>>>
>>> 2008/11/27 Eric Firing <ef...@ha...>:
>>>> It looks OK to me with mpl and numpy from svn.
>>> I tried upgrading to numpy from svn as well. Unfortunately the problem
>>> persists (I have attached a plot). I have seen the problem on two of
>>> my Ubuntu machines. Maybe it is caused by my specific setup and
>>> supporting libraries.
>>>
>>> Since I have a working solution and it does not seem to affect others
>>> (based on a survey of two:-) let us just leave the problem for now. If
>>> someone else encounter it please let me know and I will try to dive a
>>> bit into the issue. If the problem turns up again when I have a need
>>> to upgrade numpy (which is probably when matplotlib requires me to) I
>>> will also look into it.
>>>
>>> Best regards,
>>> Jesper
>>>
>>>
>>> ------------------------------------------------------------------------
>>>
>>>
>>> ------------------------------------------------------------------------
>>>
>>> -------------------------------------------------------------------------
>>>
>>> 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
>>
>>
>> -------------------------------------------------------------------------
>> 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
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>