visualpython-users

Re: [Visualpython-users] Missing contribution entry

[Bruce S. <Bru...@nc...>]

Removed, since I don't find this anywhere. Thanks.

Bruce Sherwood

Chris Lyon wrote:
> The entry:
> 
> Export a VPython scene to VRML (Michael Katz-Hyman)
> 
> on the contributions page returns a page not found.
> 

[Visualpython-users] Missing contribution entry

[Chris L. <chr...@sp...>]

The entry:

Export a VPython scene to VRML (Michael Katz-Hyman)

on the contributions page returns a page not found.

[Visualpython-users] Planetary ring formation

[Bruce S. <Bru...@nc...>]

In the contributed section of vpython.org is a link to work by Michael 
Cobb who used VPython to compute the formation of rings around Saturn 
caused by gravitational resonance with the moon Titan. And the FAQ page 
has been updated with the details of how he produced the avi video.

Bruce Sherwood

Re: [Visualpython-users] Compilation of 3.29 failed on suse 10.1

[Bruce S. <Bru...@nc...>]

Not possible to guess what went wrong with the make of the standard 
version without seeing the build.log in the src directory, which gives 
details.

As for the beta version, again it's difficult to diagnose from what you 
report, but perhaps not all the numpy pieces are in fact installed? 
Including the dev component?

Bruce Sherwood

Henk Krus wrote:
> Dear all,
> 
> please help me on this one.. on a SuSE 10.1 linux machine with 
> Python 2.4.2. After a clean (i.e. everything is there):
> 
> $ ~/python/build>  ../visual-3.2.9/configure --prefix=/usr
> 
> and
> 
> $ ~/python/build> make --debug
> GNU Make 3.80
> Copyright (C) 2002  Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.
> .
> .
> make[1]: Entering directory `/usr15/hk/python/build/src'
> Updating dependancy information 
> for ../../visual-3.2.9/src/xgl.cpp ...
> Updating dependancy information 
> for ../../visual-3.2.9/src/platlinux.cpp ...
> .
> .
> Updating dependancy information 
> for ../../visual-3.2.9/src/arrow.cpp ...
> make[1]: Leaving directory `/usr15/hk/python/build/src'
> GNU Make 3.80
> Copyright (C) 2002  Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.
> There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
> PARTICULAR PURPOSE.
> Reading makefiles...
> Updating goal targets....
>  File `all' does not exist.
>    File `log_message' does not exist.
>   Must remake target `log_message'.
> make[1]: Entering directory `/usr15/hk/python/build/src'
> This is a quiet Makefile. If make exits with an error, check 
> src/build.log to see the complete error message(s). In the event of 
> an error that you cannot debug, please send a message to 
> vis...@li..., including the files 
> config.log and src/build.log, requesting assistance.
>   Successfully remade target file `log_message'.
>    File `/home/hk/python/build/site-packages/cvisualmodule.la' does 
> not exist.
>      File `cvisualmodule.la' does not exist.
>        File `arrow.lo' does not exist.
>       Must remake target `arrow.lo'.
> Compiling ../../visual-3.2.9/src/arrow.cpp ...
> make[1]: *** [arrow.lo] Error 1
> make[1]: Leaving directory `/usr15/hk/python/build/src'
> make: *** [all-recursive] Error 1
> $ ~/python/build>
> 
> What goes wrong here???
> 
> Then I grabbed visual-4.beta16. Here configure fails on Numpy:
> 
> ...
> checking for python script directory... 
> ${prefix}/lib/python2.4/site-packages
> checking for python extension module directory... 
> ${exec_prefix}/lib/python2.4/site-packages
> checking for array in python module numpy... no
> configure: error: The numpy module could not be found but is 
> required. See numpy.sourceforge.net for downloads.
> 
> Not on the module (it's there vs. 1.0.3.0) but on the blas-lib:
> 
> configure:19565: checking for array in python module numpy
> Traceback (most recent call last):
>   File "<string>", line 1, in ?
>   File "/usr/lib/python2.4/site-packages/numpy/__init__.py", line 
> 43, in ?
>     import linalg
>   File "/usr/lib/python2.4/site-packages/numpy/linalg/__init__.py", 
> line 4, in ?
>     from linalg import *
>   File "/usr/lib/python2.4/site-packages/numpy/linalg/linalg.py", 
> line 25, in ?
>     from numpy.linalg import lapack_lite
> ImportError: /usr/lib/libblas.so.3: undefined symbol: 
> _gfortran_st_write
> configure:19592: result: no
> configure:19599: error: The numpy module could not be found but is 
> required. See numpy.sourceforge.net for downloads.
> 
> So a no go here either (blas is 
> installed, /usr/lib/libblas.so.3.0.0, but want's to write with 
> fortran).
> 
> Thanks!
> Henk
> 
> PS: I'm relatively new to Python (played a bit with Tkinter in a 
> simple code called Orka). My interest is to use Python along with 
> OpenGL (easily, drawing meshes and results so no fancy stuff like 
> 'fog', 'textures' but with 'picking displayed items' -as described 
> in the Red Book with Glut-) and the interface to f95/g95/f03 so 
> (major) parts can be handled in fortran but python can access the 
> (geometry)data in the main modules. And maybe I can write into the 
> VPython generated canvas from fortran as well (as long as one 
> passes the window id, why not?).
> 
> 
> 
> 
> 
> 
> 
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[Visualpython-users] Compilation of 3.29 failed on suse 10.1

[Henk K. <h....@cy...>]

Dear all,

please help me on this one.. on a SuSE 10.1 linux machine with 
Python 2.4.2. After a clean (i.e. everything is there):

$ ~/python/build>  ../visual-3.2.9/configure --prefix=/usr

and

$ ~/python/build> make --debug
GNU Make 3.80
Copyright (C) 2002  Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
.
.
make[1]: Entering directory `/usr15/hk/python/build/src'
Updating dependancy information 
for ../../visual-3.2.9/src/xgl.cpp ...
Updating dependancy information 
for ../../visual-3.2.9/src/platlinux.cpp ...
.
.
Updating dependancy information 
for ../../visual-3.2.9/src/arrow.cpp ...
make[1]: Leaving directory `/usr15/hk/python/build/src'
GNU Make 3.80
Copyright (C) 2002  Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
Reading makefiles...
Updating goal targets....
 File `all' does not exist.
   File `log_message' does not exist.
  Must remake target `log_message'.
make[1]: Entering directory `/usr15/hk/python/build/src'
This is a quiet Makefile. If make exits with an error, check 
src/build.log to see the complete error message(s). In the event of 
an error that you cannot debug, please send a message to 
vis...@li..., including the files 
config.log and src/build.log, requesting assistance.
  Successfully remade target file `log_message'.
   File `/home/hk/python/build/site-packages/cvisualmodule.la' does 
not exist.
     File `cvisualmodule.la' does not exist.
       File `arrow.lo' does not exist.
      Must remake target `arrow.lo'.
Compiling ../../visual-3.2.9/src/arrow.cpp ...
make[1]: *** [arrow.lo] Error 1
make[1]: Leaving directory `/usr15/hk/python/build/src'
make: *** [all-recursive] Error 1
$ ~/python/build>

What goes wrong here???

Then I grabbed visual-4.beta16. Here configure fails on Numpy:

...
checking for python script directory... 
${prefix}/lib/python2.4/site-packages
checking for python extension module directory... 
${exec_prefix}/lib/python2.4/site-packages
checking for array in python module numpy... no
configure: error: The numpy module could not be found but is 
required. See numpy.sourceforge.net for downloads.

Not on the module (it's there vs. 1.0.3.0) but on the blas-lib:

configure:19565: checking for array in python module numpy
Traceback (most recent call last):
  File "<string>", line 1, in ?
  File "/usr/lib/python2.4/site-packages/numpy/__init__.py", line 
43, in ?
    import linalg
  File "/usr/lib/python2.4/site-packages/numpy/linalg/__init__.py", 
line 4, in ?
    from linalg import *
  File "/usr/lib/python2.4/site-packages/numpy/linalg/linalg.py", 
line 25, in ?
    from numpy.linalg import lapack_lite
ImportError: /usr/lib/libblas.so.3: undefined symbol: 
_gfortran_st_write
configure:19592: result: no
configure:19599: error: The numpy module could not be found but is 
required. See numpy.sourceforge.net for downloads.

So a no go here either (blas is 
installed, /usr/lib/libblas.so.3.0.0, but want's to write with 
fortran).

Thanks!
Henk

PS: I'm relatively new to Python (played a bit with Tkinter in a 
simple code called Orka). My interest is to use Python along with 
OpenGL (easily, drawing meshes and results so no fancy stuff like 
'fog', 'textures' but with 'picking displayed items' -as described 
in the Red Book with Glut-) and the interface to f95/g95/f03 so 
(major) parts can be handled in fortran but python can access the 
(geometry)data in the main modules. And maybe I can write into the 
VPython generated canvas from fortran as well (as long as one 
passes the window id, why not?).

Re: [Visualpython-users] Animating Mesh Surface

[Bruce S. <Bru...@nc...>]

The Mesh object isn't a supported/documented Visual object, though 
perhaps something like it should be. It's just a routine in a particular 
example program faces_heightfield.py contributed by the originator of 
VPython, David Scherer. The only documentation there is, is the routine 
itself. So I'm afraid you're on your own as far as using this routine in 
your own program.

Bruce Sherwood

Kadir Haldenbilen wrote:
> Hello All,
> 
> I have a surface defined  as a Mesh in Visual as below:
> 
> x = arange(-350,350,50.0)
> y = arange(-350,350,50.0)
> 
> z = zeros( (len(x),len(y)), float )
> x,y = x[:,None]+z, y+z
> 
> seasurf = Mesh((0,1,0), color.white, x, 
> (sin((x+y)/1.2/(pi))-cos((x+y)/1.2/(pi)))*10.0-15.0, y)
> 
> seasurf.p = seasurf.model.pos*0
> 
> I get the surface OK for me.
> 
> I tried updating pos values in mesh "seasurf" for y in time, but somehow 
> could not manage it. Can anyone help me?
> 
> Thanks,
> 
> Kadir
> 
> ------------------------------------------------------------------------
> Need a vacation? Get great deals to amazing places 
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> Yahoo! Travel.
> 
> 
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> 
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[Visualpython-users] Animating Mesh Surface

[Kadir H. <kha...@ya...>]

Hello All,=0A=0AI have a surface defined  as a Mesh in Visual as below:=0A=
=0Ax =3D arange(-350,350,50.0)=0Ay =3D arange(-350,350,50.0)=0A=0Az =3D zer=
os( (len(x),len(y)), float )=0Ax,y =3D x[:,None]+z, y+z=0A=0Aseasurf =3D Me=
sh((0,1,0), color.white, x, (sin((x+y)/1.2/(pi))-cos((x+y)/1.2/(pi)))*10.0-=
15.0, y)=0A=0Aseasurf.p =3D seasurf.model.pos*0=0A=0AI get the surface OK f=
or me.=0A=0AI tried updating pos values in mesh "seasurf" for y in time, bu=
t somehow could not manage it. Can anyone help me?=0A=0AThanks,=0A=0AKadir=
=0A=0A=0A=0A=0A       =0A__________________________________________________=
__________________________________Ready for the edge of your seat? =0ACheck=
 out tonight's top picks on Yahoo! TV. =0Ahttp://tv.yahoo.com/

Re: [Visualpython-users] making objects transparent

[Bruce S. <Bru...@nc...>]

Thanks much for the attempt, Martin! The libglade-WARNING and problems 
with the mouse suggest something to try. I may never have mentioned (nor 
documented) that on Linux/Unix, Jonathan Brandmeyer installed some new 
buttons at the top of the window to change to pan mode and some other 
options. These are not present in the Windows version. You might try 
commenting out these widgets. A major place where these widgets show up 
is in display.cpp. Search for "// Glade-based UI."

Bruce Sherwood

Martin Costabel wrote:
> Bruce Sherwood wrote:
>> There is a beta version of VPython which supports transparency. See 
>> "Recent Developments" on the home page of vpython.org. Unfortunately, 
>> although the beta version seems to work okay on Linux, it has serious 
>> problems on Windows (and problems seem to be different on different 
>> Windows machines), and there is no Mac version, which is why this new 
>> version is still considered "beta".
> 
> Concerning the Mac, I have been trying for q while - with varying 
> results - to make a Fink package for 4.beta. Most recently, building 
> 4.beta16 went OK, and the resulting vpython starts up test modules and 
> shows the initial graphics window, but as soon as I touch the mouse, the 
> window disappears and python crashes.
> 
> I am still strying to make sense of the crash log, it may be a 
> libboost_python problem, because the backtrace starts with
> 
> #0  0x00033858 in PyDict_GetItem (op=0x7c14e40, key=0x0) at 
> Objects/dictobject.c:569
> #1  0x02188068 in boost::python::objects::function::call (this=0x67f1f0, 
> args=0x203a210, keywords=0x7c14e40) at 
> /sw/src/fink.build/boost1.33-1.33.1-1008/boost_1_33_1/libs/python/build/../src/object/function.cpp:183 
> 
> 
> There are also the following warnings at the console:
> 
> libglade-WARNING **: unknown property `urgency_hint' for class 
> `gtkmm__GtkWindow'
> 
> Gtk-WARNING **: gtkwidget.c:3143: widget `gtkmm__GtkToolButton' has no 
> activatable signal "clicked" without arguments
> 
> Can this be a gtk version problem?
> 

Re: [Visualpython-users] making objects transparent

[Martin C. <cos...@wa...>]

Bruce Sherwood wrote:
> There is a beta version of VPython which supports transparency. See 
> "Recent Developments" on the home page of vpython.org. Unfortunately, 
> although the beta version seems to work okay on Linux, it has serious 
> problems on Windows (and problems seem to be different on different 
> Windows machines), and there is no Mac version, which is why this new 
> version is still considered "beta".

Concerning the Mac, I have been trying for q while - with varying 
results - to make a Fink package for 4.beta. Most recently, building 
4.beta16 went OK, and the resulting vpython starts up test modules and 
shows the initial graphics window, but as soon as I touch the mouse, the 
window disappears and python crashes.

I am still strying to make sense of the crash log, it may be a 
libboost_python problem, because the backtrace starts with

#0  0x00033858 in PyDict_GetItem (op=0x7c14e40, key=0x0) at 
Objects/dictobject.c:569
#1  0x02188068 in boost::python::objects::function::call (this=0x67f1f0, 
args=0x203a210, keywords=0x7c14e40) at 
/sw/src/fink.build/boost1.33-1.33.1-1008/boost_1_33_1/libs/python/build/../src/object/function.cpp:183

There are also the following warnings at the console:

libglade-WARNING **: unknown property `urgency_hint' for class 
`gtkmm__GtkWindow'

Gtk-WARNING **: gtkwidget.c:3143: widget `gtkmm__GtkToolButton' has no 
activatable signal "clicked" without arguments

Can this be a gtk version problem?

-- 
Martin

Re: [Visualpython-users] Install Problems

[Bruce S. <Bru...@nc...>]

 From the looks of your build.log, it looks like numpy isn't installed, 
or the development version with its include files isn't installed.

I attach an improved version of INSTALL.txt (now in CVS at 
sourceforge.net) which gives more explicit installation instructions. 
Hope it helps.

Bruce Sherwood

bradley wrote:
> I recently upgraded to fedora 7 on a thinkpad T60.  I figured I would 
> give vpython 4.0 beta a try when trying to put vpython back on.  When I 
> ran configure everything went fine, but while running make I got the 
> error...
> 
> Compiling ./python/convex.cpp ...
> make[1]: *** [convex.lo] Error 1
> make[1]: Leaving directory 
> `/home/brad/MyStuff/Documents/programs/vpython/visual-4.beta16/src'
> make: *** [all-recursive] Error 1
> 
> In addition I have also attatched the src/build.log.  Does anyone know 
> what went wrong?
> 
> --Brad

[Visualpython-users] forgot the attatchment

[bradley <bj...@nc...>]

i forgot the buildlog.  here it is....
--Brad

[Visualpython-users] Install Problems

[bradley <bj...@nc...>]

I recently upgraded to fedora 7 on a thinkpad T60.  I figured I would 
give vpython 4.0 beta a try when trying to put vpython back on.  When I 
ran configure everything went fine, but while running make I got the 
error...

Compiling ./python/convex.cpp ...
make[1]: *** [convex.lo] Error 1
make[1]: Leaving directory 
`/home/brad/MyStuff/Documents/programs/vpython/visual-4.beta16/src'
make: *** [all-recursive] Error 1

In addition I have also attatched the src/build.log.  Does anyone know 
what went wrong?

--Brad

Re: [Visualpython-users] display axes in a scene

[Bruce S. <Bru...@nc...>]

Sure, simply use curve and label objects. There doesn't happen to exist 
an "axes" object currently in VPython, but there probably should, just 
for convenience. It, like the helix object, could be written in Python 
rather than C++.

Bruce Sherwood

Noko Phala wrote:
> Hi,
> 
> Is it possible to display axes (x,y,z) in a scene in vpython, perhaps at 
> the corner of the scene?
> 
> Thanks,
> 
> Noko

[Visualpython-users] display axes in a scene

[Noko P. <np...@an...>]

Hi,

Is it possible to display axes (x,y,z) in a scene in vpython, perhaps at
the corner of the scene?

Thanks,

Noko

=20

Re: [Visualpython-users] making objects transparent

[Bruce S. <Bru...@nc...>]

There is a beta version of VPython which supports transparency. See 
"Recent Developments" on the home page of vpython.org. Unfortunately, 
although the beta version seems to work okay on Linux, it has serious 
problems on Windows (and problems seem to be different on different 
Windows machines), and there is no Mac version, which is why this new 
version is still considered "beta".

Bruce Sherwood

bradley wrote:
> I am trying to make a transparent object with vpython for a 3D pong game 
> I am designing.  Does anyone know how to do this?
> 
> --Brad

[Visualpython-users] making objects transparent

[bradley <bj...@nc...>]

I am trying to make a transparent object with vpython for a 3D pong game 
I am designing.  Does anyone know how to do this?

--Brad

[Visualpython-users] Version 3.2.11 for Windows

[Bruce S. <Bru...@nc...>]

Samuel Franssens reported a bug in version 3.3.10 on Windows in the
handling of zero-length strings in the text of label objects. Now fixed
in version 3.2.11, available at vpython.org.

Bruce Sherwood

Re: [Visualpython-users] OpenGL initialization failure

[Jutta Luettmer-S. <ju...@ne...>]

Thank you very much for the message. You are right, there seems to be a 
problem with the driver/settings for my video card. I'll look into that.

Thanks again,
Jutta

-----------------------------------------------------------------
Jutta Luettmer-Strathmann
Department of Physics
University of Akron
Akron, OH 44325-4001
phone: (330) 972 8029
fax:   (330) 972 6918
email: ju...@ph...

On Thu, 5 Jul 2007, Bruce Sherwood wrote:

> I hope someone who is using Fedora will comment, but one thing you might try 
> is to run the OpenGL test routine glxgears, which I think is normally present 
> on Linux. You should see three meshed gears rotating. If not, the problem is 
> probably not with VPython but with OpenGL or X11 or associated environment 
> variables.
>
> Also, you might try "print vector(1,2,3)" after importing visual to see that 
> visual is working okay except for creating an OpenGL window.
>
> Bruce Sherwood
>
> Jutta Luettmer-Strathmann wrote:
>> Good evening,
>> 
>> I tried to install VPython on a linux workstation (Fedora Core 4, python 
>> 2.3.4). After some trouble, the "idle" window opens now and imports from 
>> visual (>>> from visual import *    works fine) however, it has trouble 
>> finding OpenGL. For example,
>> 
>>>>> floor = box(length=4, height=0.5, width=4, color=color.blue)
>> OpenGL initialization failed.
>>    Unable to create OpenGL display widget
>> 
>> At the same time, the error message
>> 
>> Xlib:  extension "GLX" missing on display ":0.0".
>> Gtk-WARNING **: invalid cast from (NULL) pointer to `GtkWidget'
>> 
>> is displayed in the window from which "vpython" was called.
>> 
>> I've tried recompiling vpython (using the suggestion under "morelinux") but 
>> that doesn't seem to help. I'd be grateful for any help.
>> 
>> Jutta
>> 
>> -----------------------------------------------------------------
>> Jutta Luettmer-Strathmann
>> Department of Physics
>> University of Akron
>> Akron, OH 44325-4001
>> phone: (330) 972 8029
>> fax:   (330) 972 6918
>> email: ju...@ph...
>> 
>> 
>> -------------------------------------------------------------------------
>> 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
>

[Visualpython-users] 4.beta16

[Bruce S. <Bru...@nc...>]

At sourceforge there is a new beta version 4.beta16 for Windows and 
Linux. The main change is to remove the lock operation in the render 
routine for faces objects, which led to blocking on Linux.

Bruce Sherwood

Re: [Visualpython-users] OpenGL initialization failure

[Bruce S. <Bru...@nc...>]

I hope someone who is using Fedora will comment, but one thing you might 
try is to run the OpenGL test routine glxgears, which I think is 
normally present on Linux. You should see three meshed gears rotating. 
If not, the problem is probably not with VPython but with OpenGL or X11 
or associated environment variables.

Also, you might try "print vector(1,2,3)" after importing visual to see 
that visual is working okay except for creating an OpenGL window.

Bruce Sherwood

Jutta Luettmer-Strathmann wrote:
> Good evening,
> 
> I tried to install VPython on a linux workstation (Fedora Core 4, python 
> 2.3.4). After some trouble, the "idle" window opens now and imports from visual 
> (>>> from visual import *    works fine) however, it has trouble finding 
> OpenGL. For example,
> 
>>>> floor = box(length=4, height=0.5, width=4, color=color.blue)
> OpenGL initialization failed.
>    Unable to create OpenGL display widget
> 
> At the same time, the error message
> 
> Xlib:  extension "GLX" missing on display ":0.0".
> Gtk-WARNING **: invalid cast from (NULL) pointer to `GtkWidget'
> 
> is displayed in the window from which "vpython" was called.
> 
> I've tried recompiling vpython (using the suggestion under "morelinux") but 
> that doesn't seem to help. I'd be grateful for any help.
> 
> Jutta
> 
> -----------------------------------------------------------------
> Jutta Luettmer-Strathmann
> Department of Physics
> University of Akron
> Akron, OH 44325-4001
> phone: (330) 972 8029
> fax:   (330) 972 6918
> email: ju...@ph...
> 
> 
> -------------------------------------------------------------------------
> 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.
> http://sourceforge.net/powerbar/db2/
> _______________________________________________
> Visualpython-users mailing list
> Vis...@li...
> https://lists.sourceforge.net/lists/listinfo/visualpython-users

[Visualpython-users] OpenGL initialization failure

[Jutta Luettmer-S. <ju...@ne...>]

Good evening,

I tried to install VPython on a linux workstation (Fedora Core 4, python 
2.3.4). After some trouble, the "idle" window opens now and imports from visual 
(>>> from visual import *    works fine) however, it has trouble finding 
OpenGL. For example,

>>> floor = box(length=4, height=0.5, width=4, color=color.blue)
OpenGL initialization failed.
   Unable to create OpenGL display widget

At the same time, the error message

Xlib:  extension "GLX" missing on display ":0.0".
Gtk-WARNING **: invalid cast from (NULL) pointer to `GtkWidget'

is displayed in the window from which "vpython" was called.

I've tried recompiling vpython (using the suggestion under "morelinux") but 
that doesn't seem to help. I'd be grateful for any help.

Jutta

-----------------------------------------------------------------
Jutta Luettmer-Strathmann
Department of Physics
University of Akron
Akron, OH 44325-4001
phone: (330) 972 8029
fax:   (330) 972 6918
email: ju...@ph...

[Visualpython-users] Blocking on faces

[Bruce S. <Bru...@nc...>]

I now realize that the problem I see with non-framed faces (including 
bar graphs) on Ubuntu Linux with Visual beta4.15 has nothing to do with 
upgrading to the latest version of Linux. Rather, the issue is a change 
made by Mikhail Temkine in April to address a problem he saw on his 
Windows machine. Here is what he wrote to me (I'd forgotten this):

"I added a lock(mtx) to faces::gl_render and now faces_heightfield 
doesn't crash anymore, like it used to. (On my machine at least)
There was a concurrency issue with render and append."

It is this new lock that is blocking forever on Linux, though it doesn't 
block on Windows. Strange. I don't understand the interactions among the 
various Visual threads, but I'm guessing that whatever problem Mikhail 
saw, this fix only happened to work but doesn't really address the 
problem he was trying to solve. I note that no other object has a lock 
in its render routine.

I'm going to remove the lock and rebuild both Windows and Linux 
versions, and wait for the heightfield problem to show up again for someone.

Bruce Sherwood

[Visualpython-users] Lock trouble

[Bruce S. <Bru...@nc...>]

Upon updating Ubuntu Linux to the latest version I find that something 
has changed in the environment to produce a problem in the beta version 
of Visual. The rendering thread (the code that generates the OpenGL 
display) has to lock out the computational thread (your own Python code) 
in order to avoid conflicts in reading or writing common resources. The 
rendering routine for faces (in faces.cpp) tries to acquire the lock and 
fails, hanging forever, while the computational thread goes merrily on 
its way forever. Because faces are used to draw vertical and horizontal 
bars in the graph package, bar graphs hang. Oddly, if the faces are 
inside a frame, there is no problem.

The good news is that the problem is absolutely reproducible, on several 
different computers including computers with brand new clean installs of 
the latest Ubuntu. The bad news is that I haven't had much time to 
devote to the problem and don't know its cause, and I don't have 
experience debugging a thread lock problem. I would welcome suggestions.

Bruce Sherwood

Re: [Visualpython-users] (no subject)

[Bruce S. <Bru...@nc...>]

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
>
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[Visualpython-users] (no subject)

[Noko P. <np...@an...>]

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