visualpython-users

Re: [Visualpython-users] vpython fink package for Mac OSX 10.3

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

Jonathan Brandmeyer wrote:


> Excellent, I got it.  I have a build going as I write this on a 10.2 box
> with Python 2.2 and an Apple-distributed GCC 3.1.

Yes, I found now that the error I am seeing comes from using gcc-3.3 
which is the standard on OSX 10.3. It goes away when I use gcc-3.1. It 
seems that the CXX library does not work with gcc-3.3. This is really 
weird, because all these things are in the end linked with the python2.3 
executable which was compiled with gcc-3.3, and C++-compiled binaries 
are, in general, not compatible between gcc-3.1 and gcc-3.3.

Anyway, if no solution is found to make the CXX stuff compatible with 
gcc-3.3, I can require that the package is built with gcc-3.1, crossing 
fingers that this will not break other things.

> First off, unless you have CPPFLAGS set to include -I/sw/include already
> as part of the fink environment, it should be set by visual-py23.info.

This is automatically set by fink.

> cvisual/Makefile is totally insensitive to the DESTDIR variable, exactly
> why is it needed?  Is the makefile not picking up on the value of
> 'prefix' for some reason?

It is, but the fink build process is like with debian or rpm: You don't 
install to the final destination, but to some build-root from which the 
package is then created. Thus the prefix is set to /sw (%p in the info 
file), but the make install has to install into 
/sw/src/root-visual-py23-2.1.9-1/sw/

Hence the need for the DESTDIR variable which is respected in all 
subdirectories except cvisual. cvisual/Makefile installs the vpython 
script directly into /sw/bin which is illegal, because in this way it 
does not get into the package.

> Since gtkglarea is distributed as a static lib, I think it should
> actually be a build-dependency and not an install dependency.

OK, noted.

> With the changes that your patch makes to OSX_SORULE, the link step
> fails with many undefined references to functions defined in the Python
> executable itself.

The "-bundle_loader $PYTHON" flag takes care of this. It tells ld to 
look for undefined symbols in the python executable. There was just a 
syntax error: -bundle_loader doesn't take a "=" sign. I removed the 
-flat_namespace, because the python executable is compiled as a 
two_level binary, but I guess this doesn't make much difference.
In any case, it compiled OK for me, both with gcc-3.3 and with gcc-3.1.

> Just exactly what does that sed script do?  I've never used sed.

This is something completely unimportant. I wanted to have something 
other than the license.txt in the doc directory. For every fink package 
there is a doc directory in /sw/share/doc, in this case 
/sw/share/doc/visual-py23. I took the docs/index.html to put there, 
renamed to visual.html, and the sed changes the links in that file so 
that they point to the other local vpython html files in 
/sw/lib/python2.3/site-packages/visual/docs. I don't know enough about 
the inner workings of vpython to see whether the latter need to remain 
in the site-packages/visual/docs directory or whether they could be 
moved to /sw/share/doc/visual, so I let them where they were installed 
by default.

> What command do you execute to build the package? (eg, the counterpart
> to dpkg-buildpackage in Debian).

The command is simply "fink install visual-py23". Fink actually creates 
a *.deb package and then uses dpkg to install it at its final 
destination. If one wants to build only the deb package without 
isntallation, the command is "fink build visual-py23".

The package will first go into the unstable tree, so that fink users 
will have to activate this. After some time, it will migrate to the 
stable tree, and in this case it can then become part of Fink's binary 
distribution. When this is achieved, Fink users can use "apt-get install 
visual-py23" to get the precompiled binary directly.

> visual/Makefile byte-compiles site-packages/visual/*.py already, why is
> the post-install script doing this as well?

I saw that the *.pyc files have the buildroot directory hardwired inside 
and suspected that this could have something to do with my error, so I 
compiled them a second time after they were installed at their final 
place. But I think this is useless, after all. OK, while I wrote this, I 
compiled it again without this PostInstScript, and the ball is still 
bouncing, so I guess I'll remove this part.

Another question: I read Kelvin Chu's installation instructions, and he 
says that gdbm3 is needed, too. Is this true? I don't see anything 
gdbm-related in the compile log.

-- 
Martin

Re: [Visualpython-users] vpython fink package for Mac OSX 10.3

[Jonathan B. <jbr...@ea...>]

On Sun, 2004-01-25 at 15:58, Martin Costabel wrote:
> Jonathan Brandmeyer wrote:
> []
> > I don't know.  I haven't seen this kind of error before.  What process
> > did you follow to build the package?  Maybe that will offer some clues
> > for further investigation.

Well, like you said, the build procedure looks pretty standard.

> I don't know if this list allows attachments. If yes, you will find 
> attached the info and patch files that constitute the Fink package 
> description. They are not very long and should be more or less 
> self-explanatory. If the attachments don't arrive, I can try to explain. 
> In any case, there is nothing extraordinary. I followed basically the 
> instructions for Unix installation on the vpython web site.
> 

Excellent, I got it.  I have a build going as I write this on a 10.2 box
with Python 2.2 and an Apple-distributed GCC 3.1.

First off, unless you have CPPFLAGS set to include -I/sw/include already
as part of the fink environment, it should be set by visual-py23.info.

cvisual/Makefile is totally insensitive to the DESTDIR variable, exactly
why is it needed?  Is the makefile not picking up on the value of
'prefix' for some reason?

Since gtkglarea is distributed as a static lib, I think it should
actually be a build-dependency and not an install dependency.

With the changes that your patch makes to OSX_SORULE, the link step
fails with many undefined references to functions defined in the Python
executable itself.

Just exactly what does that sed script do?  I've never used sed.

What command do you execute to build the package? (eg, the counterpart
to dpkg-buildpackage in Debian).

visual/Makefile byte-compiles site-packages/visual/*.py already, why is
the post-install script doing this as well?

If you force CXXFLAGS=-O2 and CFLAGS=-O2, you will cut down on the size
of the package (Autoconf adds in -g by default unless you override it).

> 
> This is for inclusion in Fink itself.


Thanks for this work!
-Jonathan Brandmeyer

P.S.  There is a driving snowstorm between me and the OSX machine I
tested your stuff on, so any testing I can do on my end is limited to
text-only for a day or so.  Finally, the connection isn't forwarding GLX
properly even though X11 is forwarding.  Oh, well.

Re: [Visualpython-users] vpython fink package for Mac OSX 10.3

[Gary P. <pa...@in...>]

----- Original Message ----- 
From: "Jonathan Brandmeyer" <jbr...@ea...>
To: <Vis...@li...>
Sent: Sunday, January 25, 2004 3:47 PM
Subject: Re: [Visualpython-users] vpython fink package for Mac OSX 10.3


> On Sun, 2004-01-25 at 15:35, Martin Costabel wrote:
> > I made a Fink package for vpython that uses python2.3 from Fink.
>
> Outstanding!

Agreed!!

One pleading request:  make it work for 10.2 also.

I for one don't plan on upgrading to 10.3 any time soon.
10.2 works for me, and I've seen lots of trouble with 10.3 discussed on the
fink disscusssion group.  I have all the trouble I need, thank you.
Additionally, there's the cost / difficulty dealing with our IT people.

-gary

[Visualpython-users] browser won't work under OS 10.3.2

[Joe H. <hea...@ct...>]

I've successfully built VPython on my iBook and my iMac using Kelvin 
Chu's instructions. I'm having two issues, one of which I've solved and 
the other I've not.

1) After installing Fink, /sw/bin isn't included in the PATH when I 
launch xterm under X11. However, if I issue "source .profile" inside an 
xterm window it gets added to PATH. There is no problem under Apple's 
Terminal (generally not used when X11 is running). Since ~/.profile 
isn't being read by the bash shell, the environment must be set 
somewhere by X11, but I've not found where yet.

2) Under Jaguar (OS 10.2.x) setting the environment variable 
BROWSER=open allowed docs to be invoked by pressing F1. This doesn't 
work under 10.3.x even when I explicitly manually set this env variable 
in an xterm. I've not yet found a solution to this. Any ideas?

Cheers,
Joe Heafner -- Astronomy/Physics Instructor (by some definitions)

Re: [Visualpython-users] vpython fink package for Mac OSX 10.3

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

Jonathan Brandmeyer wrote:
[]
> I don't know.  I haven't seen this kind of error before.  What process
> did you follow to build the package?  Maybe that will offer some clues
> for further investigation.

I don't know if this list allows attachments. If yes, you will find 
attached the info and patch files that constitute the Fink package 
description. They are not very long and should be more or less 
self-explanatory. If the attachments don't arrive, I can try to explain. 
In any case, there is nothing extraordinary. I followed basically the 
instructions for Unix installation on the vpython web site.

> Dr. Sherwood and I would like to help you release it too!  Is this
> package destined for inclusion in fink itself, or are you going to
> provide a separate repository for it?

This is for inclusion in Fink itself.

-- 
Martin

Re: [Visualpython-users] is there a function for solving a system of linear equations

[Jonathan B. <jbr...@ea...>]

On Sun, 2004-01-25 at 14:15, CHAPMAN, RICHARD wrote:
> hi
>  
> is there already a function in python to solve a set of linear
> equations when in the form
>  
> | 3  4  5  6 |
> | 2  7  2  1 |
> | 6  9  1  2 |
>  
> Assuming matrix is consistent and the fourth column is your result and
> it puts it in the form
>  
> | 1  0  0  ? |
> | 0  1  0  ? |
> | 0  0  1  ? |
>  
> where ? are the results? or a function similar to.
>  
> thanks rich

Numeric has a linear algebra subpackage[1], but I don't have any
experience with it.

HTH,
Jonathan Brandmeyer

[1] http://www.pfdubois.com/numpy/html2/numpy-18.html#pgfId-303015

Re: [Visualpython-users] vpython fink package for Mac OSX 10.3

[Jonathan B. <jbr...@ea...>]

On Sun, 2004-01-25 at 15:35, Martin Costabel wrote:
> I made a Fink package for vpython that uses python2.3 from Fink.

Outstanding!  How exactly does fink packaging work?  Are the scripts
something that should be kept in CVS for version control?

>  It 
> compiles and installs fine and the vpython script starts the IDLE 
> window, but when I try to run a demo or just run python and "import 
> visual", it crashes with an error message:
> 
>  >>> import visual
> Visual-2003-10-05
> Traceback (most recent call last):
>    File "<stdin>", line 1, in ?
>    File "/sw/lib/python2.3/site-packages/visual/__init__.py", line 81, in ?
>      scene = display()
>    File "/sw/lib/python2.3/site-packages/visual/__init__.py", line 34, 
> in __call__
>      return apply(self.constr, args, kw)
> TypeError: CXX: type error.
>  >>>
> 
> Can anybody please tell me where this might come from?

I don't know.  I haven't seen this kind of error before.  What process
did you follow to build the package?  Maybe that will offer some clues
for further investigation.

> I am a complete newbie when it comes to vpython and, for that matter, to 
> python. I would like to release this Fink package as soon as this 
> problem is solved.

Dr. Sherwood and I would like to help you release it too!  Is this
package destined for inclusion in fink itself, or are you going to
provide a separate repository for it?

Thanks,
Jonathan Brandmeyer

[Visualpython-users] vpython fink package for Mac OSX 10.3

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

I made a Fink package for vpython that uses python2.3 from Fink. It 
compiles and installs fine and the vpython script starts the IDLE 
window, but when I try to run a demo or just run python and "import 
visual", it crashes with an error message:

 >>> import visual
Visual-2003-10-05
Traceback (most recent call last):
   File "<stdin>", line 1, in ?
   File "/sw/lib/python2.3/site-packages/visual/__init__.py", line 81, in ?
     scene = display()
   File "/sw/lib/python2.3/site-packages/visual/__init__.py", line 34, 
in __call__
     return apply(self.constr, args, kw)
TypeError: CXX: type error.
 >>>

Can anybody please tell me where this might come from?

I am a complete newbie when it comes to vpython and, for that matter, to 
python. I would like to release this Fink package as soon as this 
problem is solved.

-- 
Martin

[Visualpython-users] is there a function for solving a system of linear equations

[CHAPMAN, R. <ric...@um...>]

hi
=20
is there already a function in python to solve a set of linear
equations when in the form
=20
| 3  4  5  6 |
| 2  7  2  1 |
| 6  9  1  2 |
=20
Assuming matrix is consistent and the fourth column is your result and
it puts it in the form
=20
| 1  0  0  ? |
| 0  1  0  ? |
| 0  0  1  ? |
=20
where ? are the results? or a function similar to.
=20
thanks rich

Re: [Visualpython-users] slider

[Cornelius S. <cor...@we...>]

Hi,
I solved my problem.
Thank you very much for help me.

Cornelius

[Visualpython-users] scene.select() active screen

[CHAPMAN, R. <ric...@um...>]

hi
=20
is there a function to obtain what the current active screen is, the
screen that the user is currently entering input into. if you have no
idea what scenes the "users" might have created?
=20
example application: say i wanted to animate the drawing of a line
where the user just drags the mouse.  but i do not want to have to
pass into that function what screen is currently being used. i would
like the line function to detect what screen the user is currently
using.
=20
thanks=20
=20
rich

Re: [Visualpython-users] slider

[Andrew D. <dou...@la...>]

On Sat, 17 Jan 2004, Cornelius Sicker wrote:

> Hi,
> thanks for your answer. I already tried to create a slider with
> visual.controls, i neglect to write this. I'm sorry.
> I also tried to install the current version of VPython, but this
> requires Python 2.3, and the module "controls" is already implemented in
> my version of VPython. For better representation
> I give you my code (so far I've written):
>
> slider1 = slider(x=0, y=0, width=2, length=20, action='here I don't know
> what to do')

I had some degree of success implementing some controls for a
simulation of a damped, driven pendulum.  It's about 300 lines long, so I
won't include it here, but you can download it at

  http://www.lafayette.edu/~doughera/other/python/examples/drivenpend.py

It was my first attempt, and I'm sure there are better ways to do it, but
you might find it helpful.

-- 
    Andy Dougherty		dou...@la...
    Dept. of Physics
    Lafayette College, Easton PA 18042

Re: [Visualpython-users] how to hide arrows drawn in vpython

[Bruce S. <bas...@un...>]

The following slightly modified version works fine on my computer (it 
wa. Since you don't experience the arrow becoming invisible, it is 
tempting to blame something completely extraneous to VPython, such as 
your graphics driver.

from visual import *
sphere(radius=0.05)
xaxis=arrow(pos=vector(0, 0, 0), axis=(0, 0, 0), color=color.red, 
shaftwidth=0.5)
 
xaxis.axis = vector(1, 0, 0)
# scene.mouse.getclick() # OPTIONALLY WAIT FOR ARROW TO BECOME INVISIBLE
 
#the vector is now displayed on screen
 
#now i cant seem to hide it
xaxis.visible = 0
 
#hhmm the xaxis is still visible on the screen but is no longer
# updated if i change something like position
xaxis.pos = vector(3, 0, 0)
 
#lets try to make it invisible by making the axis nothing
##xaxis.axis = vector(0, 0, 0) # THIS DOES MAKE VECTOR INVISIBLE

 
#now reshow the vector, but it never hid it in the first place, shows
#up in the position vector(3, 0, 0)
xaxis.visible = 1


CHAPMAN, RICHARD wrote:

>hi
> 
>im having problems temporarily hiding the arrow drawn on screen the
>code goes something like what follows but i added comments on what is
>actually happening. any help would be appreciated.
> 
>rich, see code below :-)
> 
>xaxis=arrow(pos=vector(0, 0, 0), axis=(0, 0, 0), color=color.red,
>shaftwidth=0.5)
> 
>xaxis.axis = vector(1, 0, 0)
> 
>#the vector is now displayed on screen
> 
>#now i cant seem to hide it
>xaxis.visible = 0
> 
>#hhmm the xaxis is still visible on the screen but is no longer
>updated if i change something like position
>xaxis.pos = vector(3, 0, 0)
> 
>#lets try to make it invisible by making the axis nothing
>xaxis.axis = vector(0, 0, 0)
> 
>#now reshow the vector, but it never hid it in the first place, shows
>up in the position vector(3, 0, 0) xaxis.visible = 1
> 
> 
>
>
>-------------------------------------------------------
>The SF.Net email is sponsored by EclipseCon 2004
>Premiere Conference on Open Tools Development and Integration
>See the breadth of Eclipse activity. February 3-5 in Anaheim, CA.
>http://www.eclipsecon.org/osdn
>_______________________________________________
>Visualpython-users mailing list
>Vis...@li...
>https://lists.sourceforge.net/lists/listinfo/visualpython-users
>  
>

[Visualpython-users] zooming

[CHAPMAN, R. <ric...@um...>]

hi
=20
is there a way so that you could draw a item say an arrow that when
you zoom in and out the arrow does not change size, it always looks to
the user like it did not change size, but the other objects on the
screen do?
=20
thanks
=20
rich

[Visualpython-users] how to hide arrows drawn in vpython

[CHAPMAN, R. <ric...@um...>]

hi
=20
im having problems temporarily hiding the arrow drawn on screen the
code goes something like what follows but i added comments on what is
actually happening. any help would be appreciated.
=20
rich, see code below :-)
=20
xaxis=3Darrow(pos=3Dvector(0, 0, 0), axis=3D(0, 0, 0), =
color=3Dcolor.red,
shaftwidth=3D0.5)
=20
xaxis.axis =3D vector(1, 0, 0)
=20
#the vector is now displayed on screen
=20
#now i cant seem to hide it
xaxis.visible =3D 0
=20
#hhmm the xaxis is still visible on the screen but is no longer
updated if i change something like position
xaxis.pos =3D vector(3, 0, 0)
=20
#lets try to make it invisible by making the axis nothing
xaxis.axis =3D vector(0, 0, 0)
=20
#now reshow the vector, but it never hid it in the first place, shows
up in the position vector(3, 0, 0) xaxis.visible =3D 1
=20
=20

Re: [Visualpython-users] slider

[Bruce S. <bas...@un...>]

Here's a specific example that does what you want:

from visual.controls import *

def update():
     k = float(int(100*(slider1.value)))/100
     title.text = '%s' % k

k = 0
title = label(text='0')
c = controls()
slider1 = slider(x=0, y=0, width=10, length=50,
                  max=6, action=lambda: update())

while 1:
     c.interact()

Perhaps you could suggest how the documentation on these controls could 
be improved? Thanks.

Bruce Sherwood

Cornelius Sicker wrote:

> Hi,
> thanks for your answer. I already tried to create a slider with
> visual.controls, i neglect to write this. I'm sorry.
> I also tried to install the current version of VPython, but this
> requires Python 2.3, and the module "controls" is already implemented in
> my version of VPython. For better representation
> I give you my code (so far I've written):
> 
> slider1 = slider(x=0, y=0, width=2, length=20, action='here I don't know
> what to do')
> 
> What should I do, if I want to change the value of  for example the
> variable "k" from 0 to 6
> in steps of 0.01 with this slider?
> 
> Thanks for the answers to my other questions, too.
> 
> -Cornelius Sicker
> 

Re: [Visualpython-users] can't bring up VPython help

[Bruce S. <bas...@un...>]

The standard VPython installer for Windows already configures IDLE in 
this way (by overwriting one of the configuration files). Open the Help 
menu (instead of pressing F1) and you should see  Visual listed as a choice.

Here is the relevant note from the Windows download page at vpython.org:

Note to experienced users of IDLE: The VPython installer overwrites 
Lib\idlelib\config-main.def to add the Visual reference manual to the 
Help menu, and to make the defaults editor-on-startup= 1 and autosave= 
1, as these have proved to be appropriate for most new users of VPython. 
You may wish to edit the file to reset these parameters to zero, or use 
the Options menu to reconfigure these options, or save a copy of the 
file before installing VPython and restore it afterwards.

Bruce Sherwood

Jonathan Brandmeyer wrote:
> On Sat, 2004-01-17 at 14:23, Joe Heafner wrote:
> 
>>Hi.
>>
>>My classes are using Python23 and VPython under Windows2000. In the new 
>>IDLE, pressing F1 only brings up general Python help and not the 
>>VPython reference docs. I suspsect this problem is related to the 
>>permissions issue that plagues our setup. When I installed the latest 
>>VPython last semester, it would only run if the user had administrative 
>>privileges. Our "IT" techs cobbled together a solution that works 
>>around the usual desktop icon and apparently other things like where 
>>students can save programs by default. Any suggestions?
>>
>>Cheers,
>>Joe Heafner -- Astronomy/Physics Instructor
> 
> 
> You can add additional documentation sources manually, by going to the
> Options menu, selecting Configure Idle..., On the "general" tab, there
> is a pane on the bottom where you can add additional documentation
> sources.  Just add the path to .../site-packages/visual/docs/index.html
> 
> Worse comes to worse, you could point it at the docs posted on
> www.vpython.org.
> 
> HTH,
> -Jonathan Brandmeyer
> 
> 
> 
> -------------------------------------------------------
> The SF.Net email is sponsored by EclipseCon 2004
> Premiere Conference on Open Tools Development and Integration
> See the breadth of Eclipse activity. February 3-5 in Anaheim, CA.
> http://www.eclipsecon.org/osdn
> _______________________________________________
> Visualpython-users mailing list
> Vis...@li...
> https://lists.sourceforge.net/lists/listinfo/visualpython-users

Re: [Visualpython-users] slider

[Cornelius S. <cor...@we...>]

Hi,
thanks for your answer. I already tried to create a slider with
visual.controls, i neglect to write this. I'm sorry.
I also tried to install the current version of VPython, but this
requires Python 2.3, and the module "controls" is already implemented in
my version of VPython. For better representation
I give you my code (so far I've written):

slider1 = slider(x=0, y=0, width=2, length=20, action='here I don't know
what to do')

What should I do, if I want to change the value of  for example the
variable "k" from 0 to 6
in steps of 0.01 with this slider?

Thanks for the answers to my other questions, too.

-Cornelius Sicker

Re: [Visualpython-users] can't bring up VPython help

[Jonathan B. <jbr...@ea...>]

On Sat, 2004-01-17 at 14:23, Joe Heafner wrote:
> Hi.
> 
> My classes are using Python23 and VPython under Windows2000. In the new 
> IDLE, pressing F1 only brings up general Python help and not the 
> VPython reference docs. I suspsect this problem is related to the 
> permissions issue that plagues our setup. When I installed the latest 
> VPython last semester, it would only run if the user had administrative 
> privileges. Our "IT" techs cobbled together a solution that works 
> around the usual desktop icon and apparently other things like where 
> students can save programs by default. Any suggestions?
> 
> Cheers,
> Joe Heafner -- Astronomy/Physics Instructor

You can add additional documentation sources manually, by going to the
Options menu, selecting Configure Idle..., On the "general" tab, there
is a pane on the bottom where you can add additional documentation
sources.  Just add the path to .../site-packages/visual/docs/index.html

Worse comes to worse, you could point it at the docs posted on
www.vpython.org.

HTH,
-Jonathan Brandmeyer

[Visualpython-users] can't bring up VPython help

[Joe H. <hea...@ct...>]

Hi.

My classes are using Python23 and VPython under Windows2000. In the new 
IDLE, pressing F1 only brings up general Python help and not the 
VPython reference docs. I suspsect this problem is related to the 
permissions issue that plagues our setup. When I installed the latest 
VPython last semester, it would only run if the user had administrative 
privileges. Our "IT" techs cobbled together a solution that works 
around the usual desktop icon and apparently other things like where 
students can save programs by default. Any suggestions?

Cheers,
Joe Heafner -- Astronomy/Physics Instructor

Re: [Visualpython-users] slider

[Bruce S. <bas...@un...>]

There is a sample program of this kind among the standard VPython demos, 
Tk-Visual.py.

Bruce Sherwood

Gary Pajer wrote:
> I'm trying to do something similar, with mixed success.
> My approach has been to build a Tkinter application that controls a vpython
> window.
> I'm trying to use the Tkinter gui to read and set values in vpython.  For
> example,
> I'm trying to display a bar representing the value of a variable (energy) by
> using a Tkinter.Canvas.Rectangle widget.  If it works, the idea is to build
> a Tkinter gui that controls and displays lots of different vpython
> parameters.
> 
> So far I've had some success setting parameters in the gui and having
> vpython respond correctly.
> 
> Less luck having the gui display values from vpython in realtime.
> 
> Question for the experts:  does this approach have any prayer or working?
> I'm concerned about having dueling Tkinter applications (mine and the
> vpython window).  I'm wondering with trepidation if I should explore threads
> ...
> 
> -gary

Re: [Visualpython-users] slider

[Gary P. <pa...@in...>]

> Hi,
> i'm using Win2k, Python 2.2.2 and VPython 2002-12-12.
> I simply want to implement a slider, which controls the value of a
variable, but i don't know how to do this.
> Is there also an easy way to inscribe the slider (title) and show its
current value?
> Another problem I have is the following: I use the gdots function of
visual.graph to plot some dots in a gdisplay. How can I clear the display?
>
> Thanks for your help.
> -Cornelius


I'm trying to do something similar, with mixed success.
My approach has been to build a Tkinter application that controls a vpython
window.
I'm trying to use the Tkinter gui to read and set values in vpython.  For
example,
I'm trying to display a bar representing the value of a variable (energy) by
using a Tkinter.Canvas.Rectangle widget.  If it works, the idea is to build
a Tkinter gui that controls and displays lots of different vpython
parameters.

So far I've had some success setting parameters in the gui and having
vpython respond correctly.

Less luck having the gui display values from vpython in realtime.

Question for the experts:  does this approach have any prayer or working?
I'm concerned about having dueling Tkinter applications (mine and the
vpython window).  I'm wondering with trepidation if I should explore threads
...

-gary

Re: [Visualpython-users] slider

[Bruce S. <bas...@un...>]

In the current version of VPython there is a module "controls" which 
lets you create sliders and buttons (albeit a bit primitive). You could 
pick up the current visual zip file from "Files useful on all platforms" 
and try it; I think it will run with Python 2.2 (but I might be wrong -- 
maybe it needs Python 2.3; it uses "properties").

It isn't documented but should be that gdots and other graph objects 
have attributes that let you get at their parents. For example:

g = gdots()

g.gdisplay is the gdisplay within which this gdots object was created.

g.gdisplay.display is the Visual display within which the graph is 
displayed, which means that gdots.gdisplay.display.visible = 0 will get 
rid of the graph window.

for obj in g.gdisplay.display.objects:
	obj.color = color.red # turns everything red

Bruce Sherwood

Cornelius Sicker wrote:

> Hi,
> i'm using Win2k, Python 2.2.2 and VPython 2002-12-12.
> I simply want to implement a slider, which controls the value of a variable, but i don't know how to do this.
> Is there also an easy way to inscribe the slider (title) and show its current value?
> Another problem I have is the following: I use the gdots function of visual.graph to plot some dots in a gdisplay. How can I clear the display?
> 
> Thanks for your help.
> -Cornelius
> ______________________________________________________________________________
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> 
> 
> 
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[Visualpython-users] slider

[Cornelius S. <cor...@we...>]

Hi,
i'm using Win2k, Python 2.2.2 and VPython 2002-12-12.
I simply want to implement a slider, which controls the value of a variable, but i don't know how to do this.
Is there also an easy way to inscribe the slider (title) and show its current value?
Another problem I have is the following: I use the gdots function of visual.graph to plot some dots in a gdisplay. How can I clear the display?

Thanks for your help.
-Cornelius
______________________________________________________________________________
Erdbeben im Iran: Zehntausende Kinder brauchen Hilfe. UNICEF hilft den
Kindern - helfen Sie mit! https://www.unicef.de/spe/spe_03.php

Re: [Visualpython-users] Efficiency

[Jonathan B. <jbr...@ea...>]

On Tue, 2004-01-13 at 00:54, James Roper wrote:
> Hi,
> 
> I'm using vpython in computational simulation.  A little concerned about 
> the efficiency, I ran the following tests:
> 
[snipped tests showing visual running in the backgronud]
> This in my view is pretty poor efficiency, considering that visual 
> python is doing nothing but displaying a static ball on the second call 
> to dostuff().  Is there anyway to tell visual python to lay off and do 
> nothing for a while?  So... in the context of my work, when I call the 
> functions that do all the hard work, i would tell visual python to do 
> nothing, and then when the functions return, i'd tell visual python to 
> start doing stuff again.  BTW, what is it doing that slows everything 
> down so much?

Visual performs all of its rendering in the background in a separate
thread.  This thread runs fast enough to render not more than 30 frames
per second in each display.  This is a feature and not a bug and is the
reason that you can do anything with the window or the objects drawn
within it without having to explicitly call some kind of update function
every time.

That said, I have been thinking of some kind of rendering
synchronization method that would allow you to do what you are talking
about.  Would you like to submit a feature request in the Sourceforge
tracker?

-Jonathan Brandmeyer

P.S.  I apologize for accidentally sending this as a private message to Mr. Roper a few min ago.