Thread: [Visualpython-users] (no subject)

Bruce asked -

>>Sorry to be dense, but could you explain what this is and what it is for? 

One can create classes sub-classed from UserVector, adding whatever methods
and attributes one might need to extend the VPython vector, but use this 
"extended" vector as one might use the standard vector in VPython code.  And
the object created from the sub-class can interact with the native VPython 
vector, e.g one can "cross(v1,v2)" where v1 is inherited from UserVector and 
v2
is a native VPython vector.

>Perhaps a paragraph of intent/utility could be included in the module? 
>And/or a routine at the end illustrating its use?

Yeah being a little lazy there.  

I am using the UserVector in a dynamic geometry toy I have been iterating 
over for some time and now brining over to VPython.

It is mostly a self-education exercise - programming, graphics, synthetic 
geometry, analytic geometry, matrix algebra.  Considering my starting point
on all these subjects, I know how much I have gotten from the process and
have become quite an enthusiast of Python\Numeric as an educational tool
and see VPython as a perfect extension.

I do hope to have something to show interested folks in a few days - so I 
would
hope you might have a look at it and see from it how I utilized the 
UserVector.

ART

I have recently downloaded Visual Python; I'm running Red Hat 6.2.
I also have Mesa installed.  When I enter python and
try to import VPython, I get this:

Python 2.0 (#1, Oct 16 2000, 18:10:03) 
[GCC 2.95.2 19991024 (release)] on linux2
Type "copyright", "credits" or "license" for more information.
>>> import visual
Visual-2000-11-26
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File "/usr/local/lib/python2.0/site-packages/visual/__init__.py", line
17, in ?
    import cvisual
ImportError: /usr/lib/libgtkgl.so.4: undefined symbol: glXUseXFont
>>> 

I've tried putting my Mesa shared object file in many different
places, but with no luck.  Am I missing another piece? I though
glXUseXFont is part of OpenGL.

Thanks

Gary

On Thu, Apr 12, 2001 at 10:00:55AM -0700, Gary Huber wrote:
> I have recently downloaded Visual Python; I'm running Red Hat 6.2.
> I also have Mesa installed.  When I enter python and
> try to import VPython, I get this:
> 
> Python 2.0 (#1, Oct 16 2000, 18:10:03) 
> [GCC 2.95.2 19991024 (release)] on linux2
> Type "copyright", "credits" or "license" for more information.
> >>> import visual
> Visual-2000-11-26
> Traceback (most recent call last):
>   File "<stdin>", line 1, in ?
>   File "/usr/local/lib/python2.0/site-packages/visual/__init__.py", line
> 17, in ?
>     import cvisual
> ImportError: /usr/lib/libgtkgl.so.4: undefined symbol: glXUseXFont
> >>> 
> 
> I've tried putting my Mesa shared object file in many different
> places, but with no luck.  Am I missing another piece? I though
> glXUseXFont is part of OpenGL.
> 
It's part of GLX. And it *does* appear in my /usr/lib/libGL.so:

nimrod:/usr/lib$ nm -D libGL.so | grep glXUseXFont
0013eb3c T Fake_glXUseXFont
0013bf68 T glXUseXFont

What version on Mesa are you trying to use here? Are you sure it's a working
installation? (does other 3d stuff work?)


ari

Yeah, mine also has glXUseXFont, according to the nm command.  It also
works fine in my C++ code.  I have Mesa 3.4-1. In addition to being in
/usr/X11R6/lib, I've copied libGL.so to /usr/lib and /usr/local/lib, to no
avail.

Gary



On Thu, 12 Apr 2001, Ari Heitner wrote:

> On Thu, Apr 12, 2001 at 10:00:55AM -0700, Gary Huber wrote:
> > I have recently downloaded Visual Python; I'm running Red Hat 6.2.
> > I also have Mesa installed.  When I enter python and
> > try to import VPython, I get this:
> > 
> > Python 2.0 (#1, Oct 16 2000, 18:10:03) 
> > [GCC 2.95.2 19991024 (release)] on linux2
> > Type "copyright", "credits" or "license" for more information.
> > >>> import visual
> > Visual-2000-11-26
> > Traceback (most recent call last):
> >   File "<stdin>", line 1, in ?
> >   File "/usr/local/lib/python2.0/site-packages/visual/__init__.py", line
> > 17, in ?
> >     import cvisual
> > ImportError: /usr/lib/libgtkgl.so.4: undefined symbol: glXUseXFont
> > >>> 
> > 
> > I've tried putting my Mesa shared object file in many different
> > places, but with no luck.  Am I missing another piece? I though
> > glXUseXFont is part of OpenGL.
> > 
> It's part of GLX. And it *does* appear in my /usr/lib/libGL.so:
> 
> nimrod:/usr/lib$ nm -D libGL.so | grep glXUseXFont
> 0013eb3c T Fake_glXUseXFont
> 0013bf68 T glXUseXFont
> 
> What version on Mesa are you trying to use here? Are you sure it's a working
> installation? (does other 3d stuff work?)
> 
> 
> ari
> 
> 
> 

On Thu, Apr 12, 2001 at 04:26:14PM -0700, Gary Huber wrote:
> Yeah, mine also has glXUseXFont, according to the nm command.  It also
> works fine in my C++ code.  I have Mesa 3.4-1. In addition to being in
> /usr/X11R6/lib, I've copied libGL.so to /usr/lib and /usr/local/lib, to no
> avail.
> 
Ok. Then do an
  ldd /usr/lib/libgtkgl.so.4
(or whatever version of libgtkgl you have cvisualmodule.so linked against).
are all the dependencies resolved? your libGL.so must be in a dir that's in
/etc/ld.so.conf ...



ari

EGO (Eyes Glazing Over)

It's hard for this bystander to comprehend how Linux users put up with this!

These dialogs sound like bad jokes.

Bruce Sherwood

--On Thursday, April 12, 2001 20:13 -0400 Ari Heitner 
<ahe...@an...> wrote:

> On Thu, Apr 12, 2001 at 04:26:14PM -0700, Gary Huber wrote:
>> Yeah, mine also has glXUseXFont, according to the nm command.  It also
>> works fine in my C++ code.  I have Mesa 3.4-1. In addition to being in
>> /usr/X11R6/lib, I've copied libGL.so to /usr/lib and /usr/local/lib, to
>> no avail.
>>
> Ok. Then do an
>   ldd /usr/lib/libgtkgl.so.4
> (or whatever version of libgtkgl you have cvisualmodule.so linked
> against). are all the dependencies resolved? your libGL.so must be in a
> dir that's in /etc/ld.so.conf ...

On Thu, Apr 12, 2001 at 09:35:55PM -0400, Bruce Sherwood wrote:
> EGO (Eyes Glazing Over)
> 
> It's hard for this bystander to comprehend how Linux users put up with this!
> 
> These dialogs sound like bad jokes.
> 

I disagree.

If the installer were properly built for these linux distributions (as it is
for Windows/Mac) things would work considerably more smoothly. If we had
separate debian, rh6.2, and rh7 packages, everything would work the first
time (and yes i would put my money where my mouth is on that one).

At least when it breaks, however, there's a simple and direct recourse to
examine the situation and determine exactly what's broken. In Windows if
your GL drivers are broken, you try installing new ones from various
sources, and pray :)




Ari

> It's hard for this bystander to comprehend how Linux users put up
> with this!

The problem isn't really the OS, but our pathetic packages.  On Windows, the
(fairly complex) job of installing shared libraries, registry entries, etc
for Python, OpenGL, Tcl/Tk, cvisual, etc is handled by the Python 2.0
installer and our own.  On Linux distributions, it should be handled by the
package manager, based on dependency information in the packages.
Unfortuantely, Ari is trying to build rpm packages without access to a Red
Hat-like distribution, which is impossible.  Everyone else is therefore
trying to do things like compile from source, which is about as painful as
you would expect.

The only thing hard to understand is that anyone likes VPython enough to put
up with this ;)

> These dialogs sound like bad jokes.

That's just because you aren't used to the particular jargon being used, so
that /usr/lib/libgtkgl.so.4 sounds slightly "worse" to your ears than, say,
c:\windows\system\opengl32.dll.  These problems don't seem a lot worse than
the installation headaches that forced us to build our own Python
distribution for 1.5.2.

What is desperately needed to fix this is someone with a Red Hat system, and
the time and minimal expertise required to build packages.  I would also
advocate static linking against a few things like libstdc++ if possible,
even though that goes against normal practice on Linux.

Dave

> --On Thursday, April 12, 2001 20:13 -0400 Ari Heitner
> <ahe...@an...> wrote:
>
> > On Thu, Apr 12, 2001 at 04:26:14PM -0700, Gary Huber wrote:
> >> Yeah, mine also has glXUseXFont, according to the nm command.  It also
> >> works fine in my C++ code.  I have Mesa 3.4-1. In addition to being in
> >> /usr/X11R6/lib, I've copied libGL.so to /usr/lib and /usr/local/lib, to
> >> no avail.
> >>
> > Ok. Then do an
> >   ldd /usr/lib/libgtkgl.so.4
> > (or whatever version of libgtkgl you have cvisualmodule.so linked
> > against). are all the dependencies resolved? your libGL.so must be in a
> > dir that's in /etc/ld.so.conf ...

> --On Friday, April 13, 2001 5:06 PM -0400 David Scherer 
<dsc...@vy...> wrote:

> What is desperately needed to fix this is someone with a Red Hat system, 
and
> the time and minimal expertise required to build packages.

Would my Mandrake installation be close enough to Red Hat to serve?     Ari 
could borrow my notebook for a day, or I could try to aquire the minimal 
expertise required ...

Gary:

I think this is the problem that is talked about on the website with
regard to RH6.2.   I was getting similar errors with my installation,
until I copied over the cvisualmodule.so from the vpython website over the
/usr/lib/python1.5/site-packages/cvisualmodule.so

Now, everything is working PERFECTLY for me!

Thank you so much, everyone, especially Ari...

Andrew


On Thu, 12 Apr 2001, Gary Huber wrote:

> I have recently downloaded Visual Python; I'm running Red Hat 6.2.
> I also have Mesa installed.  When I enter python and
> try to import VPython, I get this:
> 
> Python 2.0 (#1, Oct 16 2000, 18:10:03) 
> [GCC 2.95.2 19991024 (release)] on linux2
> Type "copyright", "credits" or "license" for more information.
> >>> import visual
> Visual-2000-11-26
> Traceback (most recent call last):
>   File "<stdin>", line 1, in ?
>   File "/usr/local/lib/python2.0/site-packages/visual/__init__.py", line
> 17, in ?
>     import cvisual
> ImportError: /usr/lib/libgtkgl.so.4: undefined symbol: glXUseXFont
> >>> 
> 
> I've tried putting my Mesa shared object file in many different
> places, but with no luck.  Am I missing another piece? I though
> glXUseXFont is part of OpenGL.
> 
> Thanks
> 
> Gary
> 
> 
> _______________________________________________
> Visualpython-users mailing list
> Vis...@li...
> http://lists.sourceforge.net/lists/listinfo/visualpython-users
> 

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Hi users,

I have the following tiny problem:

I have a list of matrices, say A, and I want to plot the coordinates
using a pre-detemined function (call it draw) that actually plots the
points as spheres (i.e. atom lattice). I want to plot the matrices in A
one after the other on the same screen (to see the lattice structure
evolution).My program:

  =20

for points in A:

   draw(points)

=20

only draws the first matrix/structure and does not evolve. What's the
trick?

=20

Thanks in advance,

Noko

=20

You need to give us more of the program; this isn't enough to be able to 
diagnosis your problem.

Bruce Sherwood

Noko Phala wrote:
>
> Hi users,
>
> I have the following tiny problem:
>
> I have a list of matrices, say A, and I want to plot the coordinates 
> using a pre-detemined function (call it draw) that actually plots the 
> points as spheres (i.e. atom lattice). I want to plot the matrices in 
> A one after the other on the same screen (to see the lattice structure 
> evolution).My program:
>
> for points in A:
>
> draw(points)
>
> only draws the first matrix/structure and does not evolve. What’s the 
> trick?
>
> Thanks in advance,
>
> Noko
>
> ------------------------------------------------------------------------
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by DB2 Express
> Download DB2 Express C - the FREE version of DB2 express and take
> control of your XML. No limits. Just data. Click to get it now.
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> _______________________________________________
> Visualpython-users mailing list
> Vis...@li...
> https://lists.sourceforge.net/lists/listinfo/visualpython-users
>   

Hi,

 I've tried to build from source on Ubuntu 10.10, but ran into the following error during link.

 /bin/sed: can't read /usr/lib/libgdk_pixbuf-2.0.la: No such file or directory
 libtool: link: `/usr/lib/libgdk_pixbuf-2.0.la' is not a valid libtool archive

 It appears that is related to this:
http://www.debian.org/doc/debian-policy/ch-files.html#s-libraries 
 referred to by this thread:
https://bugs.launchpad.net/ubuntu/+source/gdk-pixbuf/+bug/665768 
 Where, about half way down it says that .la files are not longer distributed if they don't conform.

 There is a workround (which I've not yet had time to try).

 But perhaps the proper fix should be applied?

 Cheers,
 Jason.

 
I am using the extrusion
object library, path library of Vpyhon for my project. my program simply
extracts or parses G-codes with X,Y, Z coordinates, the program then uses this
extracted points as my path, a 2D square shape is then extruded through these points
or path in that sequence.
the problem is, these
points are line segments, where a line segment is define by two points i.e
X1,Y1,Z1 and X2,Y2,Z2. Now if the third point X3,Y3Z3 is sharp turn, i.e the
angle between the line segment becomes > 270, the extrusion generates very
long spikes or glitches which makes my work messy. my G-codes are all accurate,
because it is tested. this is a special case where the preceding point makes
that sharp turn. i showed it to some programmers and they say it might be a bug
with vpython extrusion library. i can share my program with you, or pictures of
what i mean. hope i get a response from you. thanks
1Attached file| 6KB

________________________________




 
I am using the extrusion
object library, path library of Vpyhon for my project. my program simply
extracts or parses G-codes with X,Y, Z coordinates, the program then uses this
extracted points as my path, a 2D square shape is then extruded through these points
or path in that sequence.
the problem is, these
points are line segments, where a line segment is define by two points i.e
X1,Y1,Z1 and X2,Y2,Z2. Now if the third point X3,Y3Z3 is sharp turn, i.e the
angle between the line segment becomes > 270, the extrusion generates very
long spikes or glitches which makes my work messy. my G-codes are all accurate,
because it is tested. this is a special case where the preceding point makes
that sharp turn. i showed it to some programmers and they say it might be a bug
with vpython extrusion library. i can share my program with you, or pictures of
what i mean. hope i get a response from you. thanks
1Attached file| 6KB

Can you share the part of the code in which is made the extrusion?
and if is possible, upload an image and post the link. I had a similar 
problem before, but for don´t talk on the air, is better to see the 
example and try to find the specific solution.
Eric.
El 16/04/2012 22:12, sufyan fehe escribió:
>
>
>
> ------------------------------------------------------------------------
> **
>
> I am using the extrusion object library, path library of Vpyhon for my 
> project. my program simply extracts or parses G-codes with X,Y, Z 
> coordinates, the program then uses this extracted points as my path, a 
> 2D square shape is then extruded through these points or path in that 
> sequence.
> the problem is, these points are line segments, where a line segment 
> is define by two points i.e X1,Y1,Z1 and X2,Y2,Z2. Now if the third 
> point X3,Y3Z3 is sharp turn, i.e the angle between the line segment 
> becomes > 270, the extrusion generates very long spikes or glitches 
> which makes my work messy. my G-codes are all accurate, because it is 
> tested. this is a special case where the preceding point makes that 
> sharp turn. i showed it to some programmers and they say it might be a 
> bug with vpython extrusion library. i can share my program with you, 
> or pictures of what i mean. hope i get a response from you. thanks
> *1*Attached file| *6*KB
>
>
>
>
> ------------------------------------------------------------------------------
> Better than sec? Nothing is better than sec when it comes to
> monitoring Big Data applications. Try Boundary one-second
> resolution app monitoring today. Free.
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>
> _______________________________________________
> Visualpython-users mailing list
> Vis...@li...
> https://lists.sourceforge.net/lists/listinfo/visualpython-users

I'm afraid this is a feature, not a bug. There just isn't any way that
I can think of for such a sharp turn to work in something called an
"extrusion". Think about creating such an object by extruding metal
and you may see that this is a fundamental problem.

In the example program "extrusion_overview.py", step through the first
page to get an index, then choose page 12 to see an illustration of
the problem.

On the other hand, perhaps you or someone else can come up with some
scheme that would work better.

Bruce Sherwood

On Mon, Apr 16, 2012 at 8:12 PM, sufyan fehe <sis...@ya...> wrote:
> I am using the extrusion object library, path library of Vpyhon for my
> project. my program simply extracts or parses G-codes with X,Y, Z
> coordinates, the program then uses this extracted points as my path, a 2D
> square shape is then extruded through these points or path in that sequence.
> the problem is, these points are line segments, where a line segment is
> define by two points i.e X1,Y1,Z1 and X2,Y2,Z2. Now if the third point
> X3,Y3Z3 is sharp turn, i.e the angle between the line segment becomes > 270,
> the extrusion generates very long spikes or glitches which makes my work
> messy. my G-codes are all accurate, because it is tested. this is a special
> case where the preceding point makes that sharp turn. i showed it to some
> programmers and they say it might be a bug with vpython extrusion library. i
> can share my program with you, or pictures of what i mean. hope i get a
> response from you. thanks
> 1 Attached file| 6KB

http://skyspark.net/wp-admin/wmnhl.php?owmi=owmi

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