visualpython-users

Re: [Visualpython-users] 1 objectlist and 2 displays

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

Thanks much for showing me how to avoid the dictionary!

Bruce Sherwood

----- Original Message -----
From: "Cettinich Edwin (LWE)" <edw...@lw...>
To: "Bruce Sherwood" <bas...@un...>;
<vis...@li...>
Sent: Wednesday, November 06, 2002 4:35 AM
Subject: AW: [Visualpython-users] 1 objectlist and 2 displays


Thanks a lot. That helps.

Although I prefer a solution with exactly one object shown in two displays
my hope has gone and I suppose it will not be realizable. So I'll go to
implement some obj-management which can handle several displays.

By the way: There is no need to convert obj.__class__ to a character string.
Here's your program without dictionary:
################################
from visual import *

x = 300
y = 400
w = 200
h = 200
eyeangle = 0.15 # interocular angle
left = display(x=x, y=y, width=w, height=h)
right = display(x=x+w, y=y, width=w, height=h)
left.select()

b1=box(pos=(-1,0,0), color=color.red)
b2=box(pos=(1,-1,0), color=color.cyan)
a1=arrow(pos=(-0.5,0,0), axis=(1,-1,0), color=color.yellow)

right.select()
for obj in left.objects:
    newobj=obj.__class__()                       # create object in 2nd
window
    for member in obj.__members__:
        if member == 'display': continue # avoid putting into scene1
        exec 'newobj.'+member+'=obj.'+member # set attribute

while 1:
    right.up = left.up
    leftforward = left.center-left.mouse.camera
    right.forward = rotate(leftforward, angle=eyeangle, axis=left.up)
################################

Edwin Cettinich

AW: [Visualpython-users] 1 objectlist and 2 displays

[Cettinich E. (LWE) <edw...@lw...>]

Thanks a lot. That helps.=20

Although I prefer a solution with exactly one object shown in two displays =
my hope has gone and I suppose it will not be realizable. So I'll go to imp=
lement some obj-management which can handle several displays.=20

By the way: There is no need to convert obj.__class__ to a character string=
=2E
Here's your program without dictionary:
################################
from visual import *

x =3D 300
y =3D 400
w =3D 200
h =3D 200
eyeangle =3D 0.15 # interocular angle
left =3D display(x=3Dx, y=3Dy, width=3Dw, height=3Dh)
right =3D display(x=3Dx+w, y=3Dy, width=3Dw, height=3Dh)
left.select()

b1=3Dbox(pos=3D(-1,0,0), color=3Dcolor.red)
b2=3Dbox(pos=3D(1,-1,0), color=3Dcolor.cyan)
a1=3Darrow(pos=3D(-0.5,0,0), axis=3D(1,-1,0), color=3Dcolor.yellow)

right.select()
for obj in left.objects:
    newobj=3Dobj.__class__()                       # create object in 2nd w=
indow
    for member in obj.__members__:
        if member =3D=3D 'display': continue # avoid putting into scene1
        exec 'newobj.'+member+'=3Dobj.'+member # set attribute

while 1:
    right.up =3D left.up
    leftforward =3D left.center-left.mouse.camera
    right.forward =3D rotate(leftforward, angle=3Deyeangle, axis=3Dleft.up)
################################

Edwin Cettinich

> -----Urspr=FCngliche Nachricht-----
> Von:	Bruce Sherwood [SMTP:bas...@un...]
> Gesendet am:	Dienstag, 5. November 2002 17:22
> An:	Cettinich Edwin (LWE); vis...@li...
> Betreff:	Re: [Visualpython-users] 1 objectlist and 2 displays
>=20
> I think the problem with copying objects to a second window is that you
> can't assign to scene.objects, you can only read it.
>=20
> Below is a kludge to copy objects from one window into another. Maybe
> someone else can think of a way to convert obj.__class__ to a character
> string so that it can be used in exec, instead of having to create a
> dictionary of existing Visual objects? Or some other scheme altogether?
>=20
> This program creates two cubes and an arrow on the left, then copies thes=
e
> objects into a second window on the right. The camera positions are adjus=
ted
> to be different in the two windows, in order to provide a true stereo pai=
r
> that can be merged by making your eyes "wall-eyed" (the opposite of
> cross-eyed). Zoom/rotate in the left window and both camera positions cha=
nge
> to continue to give you a 3D look. I think I don't have the camera angles
> quite right, because I get a headache after brief viewing!
>=20
> Bruce Sherwood
>=20
> from visual import *
> vobjects =3D {box:'box', sphere:'sphere', cylinder:'cylinder',
>             arrow:'arrow', cone:'cone', ring:'ring',
>             curve:'curve', convex:'convex', label:'label',
>             frame:'frame', faces:'faces'}
> x =3D 300
> y =3D 400
> w =3D 200
> h =3D 200
> eyeangle =3D 0.15 # interocular angle
> left =3D display(x=3Dx, y=3Dy, width=3Dw, height=3Dh)
> right =3D display(x=3Dx+w, y=3Dy, width=3Dw, height=3Dh)
> left.select()
>=20
> b1=3Dbox(pos=3D(-1,0,0), color=3Dcolor.red)
> b2=3Dbox(pos=3D(1,-1,0), color=3Dcolor.cyan)
> a1=3Darrow(pos=3D(-0.5,0,0), axis=3D(1,-1,0), color=3Dcolor.yellow)
>=20
> right.select()
> for obj in left.objects:
>     exec 'newobj=3D'+vobjects[obj.__class__]+'()' # create object in 2nd
> window
>     for member in obj.__members__:
>         if member =3D=3D 'display': continue # avoid putting into scene1
>         exec 'newobj.'+member+'=3Dobj.'+member # set attribute
>=20
> while 1:
>     right.up =3D left.up
>     leftforward =3D left.center-left.mouse.camera
>     right.forward =3D rotate(leftforward, angle=3Deyeangle, axis=3Dleft.u=
p)
>=20
>=20
> ----- Original Message -----
> From: "Cettinich Edwin (LWE)" <edw...@lw...>
> To: <vis...@li...>
> Sent: Tuesday, November 05, 2002 4:36 AM
> Subject: [Visualpython-users] 1 objectlist and 2 displays
>=20
>=20
> Hi,
>=20
> I try to make 1 objectlist visible in 2 displays.
> But neither
> ########################################>=20
> from visual import *
> scene1=3Ddisplay(title=3D"1st")
> b=3Dbox(x=3D-1)
> b=3Dbox(x=3D1,y=3D-1)
> scene2=3Ddisplay(title=3D"2nd")
> scene2.objects=3Dscene1.objects
> ########################################
> nor
> ########################################
> import copy
> from visual import *
> scene1=3Ddisplay(title=3D"1st")
> b=3Dbox(x=3D-1)
> b=3Dbox(x=3D1,y=3D-1)
> scene2=3Ddisplay(title=3D"2nd")
> scene2.objects=3Dcopy.deepcopy(scene1.objects)
> ########################################
> could make scene2 show the objects owned by scene1.
>=20
> Does anyone have a suggestion what to do?
>=20
> Thanks,
>=20
> Edwin
>=20
>=20
>=20
>=20
> -------------------------------------------------------
> This sf.net email is sponsored by: See the NEW Palm
> Tungsten T handheld. Power & Color in a compact size!
> http://ads.sourceforge.net/cgi-bin/redirect.pl?palm0001en
> _______________________________________________
> Visualpython-users mailing list
> Vis...@li...
> https://lists.sourceforge.net/lists/listinfo/visualpython-users
>=20
>=20
>=20
>=20

Re: [Visualpython-users] 1 objectlist and 2 displays

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

I think the problem with copying objects to a second window is that you
can't assign to scene.objects, you can only read it.

Below is a kludge to copy objects from one window into another. Maybe
someone else can think of a way to convert obj.__class__ to a character
string so that it can be used in exec, instead of having to create a
dictionary of existing Visual objects? Or some other scheme altogether?

This program creates two cubes and an arrow on the left, then copies these
objects into a second window on the right. The camera positions are adjusted
to be different in the two windows, in order to provide a true stereo pair
that can be merged by making your eyes "wall-eyed" (the opposite of
cross-eyed). Zoom/rotate in the left window and both camera positions change
to continue to give you a 3D look. I think I don't have the camera angles
quite right, because I get a headache after brief viewing!

Bruce Sherwood

from visual import *
vobjects = {box:'box', sphere:'sphere', cylinder:'cylinder',
            arrow:'arrow', cone:'cone', ring:'ring',
            curve:'curve', convex:'convex', label:'label',
            frame:'frame', faces:'faces'}
x = 300
y = 400
w = 200
h = 200
eyeangle = 0.15 # interocular angle
left = display(x=x, y=y, width=w, height=h)
right = display(x=x+w, y=y, width=w, height=h)
left.select()

b1=box(pos=(-1,0,0), color=color.red)
b2=box(pos=(1,-1,0), color=color.cyan)
a1=arrow(pos=(-0.5,0,0), axis=(1,-1,0), color=color.yellow)

right.select()
for obj in left.objects:
    exec 'newobj='+vobjects[obj.__class__]+'()' # create object in 2nd
window
    for member in obj.__members__:
        if member == 'display': continue # avoid putting into scene1
        exec 'newobj.'+member+'=obj.'+member # set attribute

while 1:
    right.up = left.up
    leftforward = left.center-left.mouse.camera
    right.forward = rotate(leftforward, angle=eyeangle, axis=left.up)


----- Original Message -----
From: "Cettinich Edwin (LWE)" <edw...@lw...>
To: <vis...@li...>
Sent: Tuesday, November 05, 2002 4:36 AM
Subject: [Visualpython-users] 1 objectlist and 2 displays


Hi,

I try to make 1 objectlist visible in 2 displays.
But neither
########################################
from visual import *
scene1=display(title="1st")
b=box(x=-1)
b=box(x=1,y=-1)
scene2=display(title="2nd")
scene2.objects=scene1.objects
########################################
nor
########################################
import copy
from visual import *
scene1=display(title="1st")
b=box(x=-1)
b=box(x=1,y=-1)
scene2=display(title="2nd")
scene2.objects=copy.deepcopy(scene1.objects)
########################################
could make scene2 show the objects owned by scene1.

Does anyone have a suggestion what to do?

Thanks,

Edwin




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Re: [Visualpython-users] 1 objectlist and 2 displays

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

I think the problem with copying objects to a second window is that you
can't assign to scene.objects, you can only read it.

Below is a kludge to copy objects from one window into another. Maybe
someone else can think of a way to convert obj.__class__ to a character
string so that it can be used in exec, instead of having to create a
dictionary of existing Visual objects? Or some other scheme altogether?

This program creates two cubes and an arrow on the left, then copies these
objects into a second window on the right. The camera positions are adjusted
to be different in the two windows, in order to provide a true stereo pair
that can be merged by making your eyes "wall-eyed" (the opposite of
cross-eyed). Zoom/rotate in the left window and both camera positions change
to continue to give you a 3D look. I think I don't have the camera angles
quite right, because I get a headache after brief viewing!

Bruce Sherwood

from visual import *
vobjects = {box:'box', sphere:'sphere', cylinder:'cylinder',
            arrow:'arrow', cone:'cone', ring:'ring',
            curve:'curve', convex:'convex', label:'label',
            frame:'frame', faces:'faces'}
x = 300
y = 400
w = 200
h = 200
eyeangle = 0.15 # interocular angle
left = display(x=x, y=y, width=w, height=h)
right = display(x=x+w, y=y, width=w, height=h)
left.select()

b1=box(pos=(-1,0,0), color=color.red)
b2=box(pos=(1,-1,0), color=color.cyan)
a1=arrow(pos=(-0.5,0,0), axis=(1,-1,0), color=color.yellow)

right.select()
for obj in left.objects:
    exec 'newobj='+vobjects[obj.__class__]+'()' # create object in 2nd
window
    for member in obj.__members__:
        if member == 'display': continue # avoid putting into scene1
        exec 'newobj.'+member+'=obj.'+member # set attribute

while 1:
    right.up = left.up
    leftforward = left.center-left.mouse.camera
    right.forward = rotate(leftforward, angle=eyeangle, axis=left.up)


----- Original Message -----
From: "Cettinich Edwin (LWE)" <edw...@lw...>
To: <vis...@li...>
Sent: Tuesday, November 05, 2002 4:36 AM
Subject: [Visualpython-users] 1 objectlist and 2 displays


Hi,

I try to make 1 objectlist visible in 2 displays.
But neither
########################################
from visual import *
scene1=display(title="1st")
b=box(x=-1)
b=box(x=1,y=-1)
scene2=display(title="2nd")
scene2.objects=scene1.objects
########################################
nor
########################################
import copy
from visual import *
scene1=display(title="1st")
b=box(x=-1)
b=box(x=1,y=-1)
scene2=display(title="2nd")
scene2.objects=copy.deepcopy(scene1.objects)
########################################
could make scene2 show the objects owned by scene1.

Does anyone have a suggestion what to do?

Thanks,

Edwin




-------------------------------------------------------
This sf.net email is sponsored by: See the NEW Palm
Tungsten T handheld. Power & Color in a compact size!
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_______________________________________________
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Vis...@li...
https://lists.sourceforge.net/lists/listinfo/visualpython-users

[Visualpython-users] 1 objectlist and 2 displays

[Cettinich E. (LWE) <edw...@lw...>]

Hi,

I try to make 1 objectlist visible in 2 displays.
But neither
########################################
from visual import *
scene1=3Ddisplay(title=3D"1st")
b=3Dbox(x=3D-1)
b=3Dbox(x=3D1,y=3D-1)
scene2=3Ddisplay(title=3D"2nd")
scene2.objects=3Dscene1.objects
########################################
nor
########################################
import copy
from visual import *
scene1=3Ddisplay(title=3D"1st")
b=3Dbox(x=3D-1)
b=3Dbox(x=3D1,y=3D-1)
scene2=3Ddisplay(title=3D"2nd")
scene2.objects=3Dcopy.deepcopy(scene1.objects)
########################################
could make scene2 show the objects owned by scene1.

Does anyone have a suggestion what to do?

Thanks,

Edwin

RE: [Visualpython-users] Changing the lighting in vpythonB

[David S. <da...@vi...>]

> One of the reasons I wanted to get into Vpython was to make 
> astronomical demos (parallax, phases of the moon, etc).  To 
> get phases in the solar system right, you need to have the 
> light source at the center (the sun). Also, the sun shouldn't 
> have a dark side.  Is there any way to tell Visual that the 
> source of light is at the origin (or some other point in the 
> space?).  So far, I've only been able to change the direction 
> and intensity 
> of the lighting, not it's source position (it seems to come 
> from off-screen).

Sorry, but no.  Visual's lighting calculations currently assume a
constant direction for each light (as opposed to a constant position).

> If not, is there a way to have an object "ignore" the 
> lighting (so that it 
> doesn't have a dark side)?  That way, I could try to fake out 
> central lighting by continuously updating the lighting 
> direction to be from behind the sun (but then the sun is 
> dark).  Not perfect, but a step in the right direction.

You may be able to approximate this behavior by setting the color of the
sun to something like (100,100,100).  This is not really supported by
Visual by design, but I believe the current implementation happens to
give this behavior in all cases.

Dave

[Visualpython-users] Changing the lighting in vpythonB

[Chris B. <bu...@hv...>]

Hi,

One of the reasons I wanted to get into Vpython was to make astronomical
demos (parallax, phases of the moon, etc).  To get phases in the solar
system right, you need to have the light source at the center (the sun).
Also, the sun shouldn't have a dark side.  Is there any way to tell Visual
that the source of light is at the origin (or some other point in the
space?).  So far, I've only been able to change the direction and intensity 
of the lighting, not it's source position (it seems to come from off-screen).

If not, is there a way to have an object "ignore" the lighting (so that it 
doesn't have a dark side)?  That way, I could try to fake out central
lighting by continuously updating the lighting direction to be from
behind the sun (but then the sun is dark).  Not perfect, but a step in
the right direction.

Thanks,

Chris

--
Chris Burns
Visiting Assistant Professor
Dept. of physics and astronomy, Swarthmore College
cb...@sw...      http://hven.swarthmore.edu/~burns

[Visualpython-users] Re: objects in graphics windows?

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

Here is an answer to a question from Joe Heafner. It is possible to plot
Visual objects in a graph, but they'll typically be distorted, as seen in
the following example.

from visual.graph import *

gd = gdisplay()
gc = gcurve()
gc.plot(pos=(0,0))
gc.plot(pos=(10,2))
sphere(display=gd.display, pos=(5,1), radius=0.5, color=color.cyan)

----- Original Message -----
From: "Joe Heafner" <hea...@vn...>
To: <bas...@un...>
Sent: Wednesday, October 23, 2002 5:20 PM
Subject: objects in graphics windows?


> Hi.
> I had this idea for a program in which the user clicks on a point on a
potential energy graph and at the position of the mouse click, an arrow is
drawn to visualize the component of force. However, it appears that objects
can't share the same window as a graph. Is this correct?
>
>
> Cheers,
> Joe Heafner - Instructional Astronomy and Physics
> Home Page http://users.vnet.net/heafnerj/index.html
> I don't have a Lexus, but I do have a Mac. Same thing.
>
>

[Visualpython-users] Problems using cvs

[My V. F. <wag...@vd...>]

Hi,

I tried to get the latest version of vpython via cvs.
However, it hangs up

cvs -d:pserver:ano...@cv...:/cvsroot/visualpython co cvisual
? cvisual/Makefile.ori
? cvisual/Mac/.new.cvisual.p
cvs server: Updating cvisual
M cvisual/Makefile
cvs server: Updating cvisual/CXX
cvs server: Updating cvisual/CXX/Demo
cvs server: Updating cvisual/CXX/Doc
cvs server: Updating cvisual/CXX/Include
cvs server: Updating cvisual/CXX/Src
cvs server: Updating cvisual/Mac

That's all.

Any suggestions ?

Nils

Re: [Visualpython-users] Or a ready conversion to a web based format?

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

I don't know the details, but Wolfgang Christian at Davidson College in
North Carolina has talked about doing something vaguely reminiscent of this.

At the risk of stating the obvious, while it would be nice to try to create
a web plugin for VPython, note that once a user has installed VPython (which
is functionally equivalent to installing a web plugin), it works fairly well
to post a VPython program and have the user copy and paste it into IDLE and
run. I have done this with my own physics students with success. The
difference from Java is that often (not always) a user already has Java
installed, and you can display inside a web page.

Bruce Sherwood

----- Original Message -----
From: "Robert Robinson" <Rob...@ma...>
To: <vis...@li...>
Sent: Monday, October 14, 2002 3:15 PM
Subject: [Visualpython-users] Or a ready conversion to a web based format?


>
> Does anyone know of a quick way to translate Vpython programs to a
language
> such as Java for use as web applets?
>
> Robert Balogh-Robinson, Physics
> Chair, Department of Chemistry and Physics
> Marist College School of Science
> (845)-575-3000 X 2242
> Rob...@Ma...
>
>
>
>
> -------------------------------------------------------
> This sf.net email is sponsored by:ThinkGeek
> Welcome to geek heaven.
> http://thinkgeek.com/sf
> _______________________________________________
> Visualpython-users mailing list
> Vis...@li...
> https://lists.sourceforge.net/lists/listinfo/visualpython-users
>

Re: [Visualpython-users] Or a ready conversion to a web based format?

[Martin G. <ge...@la...>]

On Mon, 14 Oct 2002, Joe Heafner wrote:

> > From: "Robert Robinson" <Rob...@ma...>
> > 
> > Does anyone know of a quick way to translate Vpython programs to a language
> > such as Java for use as web applets?
> > 
> Along these same lines, I've been wondering if it's even possible to embed a VPython program (or even a plain Python program for that matter) in a web page at all.
> 
> 
> Cheers,
> Joe Heafner - Instructional Astronomy and Physics
> Home Page http://users.vnet.net/heafnerj/index.html
> I don't have a Lexus, but I do have a Mac. Same thing.
> 

I can think of two routes to achieve these goals...but these are just
general directions to head, actually getting there will take some work!

(1) Jython -- the java implementation of python; but as to how one goes
    about constructing web applets using jython, I am completely ignorant.
    And can you even successfully import visual in jython?

(2) Grail -- this was a browser written in python+tkinter, which could
    accept python code for client side scripts; but development seems
    to have halted (last release was March 2000) and I very much doubt
    it could run visual python applets without some real hacking. 

Regards,
Marty Gelfand
Dept of Physics, Colorado State

Re: [Visualpython-users] Or a ready conversion to a web based format?

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

> From: "Robert Robinson" <Rob...@ma...>
> 
> Does anyone know of a quick way to translate Vpython programs to a language
> such as Java for use as web applets?
> 
Along these same lines, I've been wondering if it's even possible to embed a VPython program (or even a plain Python program for that matter) in a web page at all.


Cheers,
Joe Heafner - Instructional Astronomy and Physics
Home Page http://users.vnet.net/heafnerj/index.html
I don't have a Lexus, but I do have a Mac. Same thing.

[Visualpython-users] Or a ready conversion to a web based format?

[Robert R. <Rob...@ma...>]

Does anyone know of a quick way to translate Vpython programs to a language
such as Java for use as web applets?

Robert Balogh-Robinson, Physics
Chair, Department of Chemistry and Physics
Marist College School of Science
(845)-575-3000 X 2242
Rob...@Ma...

[Visualpython-users] Showing VPython over MS Net Meeting...

[IVES,THOM (HP-Boise,ex1) <tho...@hp...>]

VPython Users,

This morning I was posed and ready to show some results through the
visualization power of VPython, but Bill Gates said, "No."

It won't share, and when vpython is clicked in the list of programs to
share, netmeeting never puts a check mark by it.

I then tried, after the meeting, to share the whole desktop with another
computer, but the vpython view does not get updated on the remote computer
as you zoom and rotate on the main computer, and it rarely shows the vpython
screen contents at all, although it does show the border.

Does anyone know of a possible fix for NetMeeting?

Thom

[Visualpython-users] fixes

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

A user pointed out to me that the link for downloading Python 2.2 for
Windows was broken. I don't know whether the Python ftp server is down or is
no longer maintained, but in any case I've changed the link to point to the
current Python 2.2 install (actually 2.2.1).

I also fixed very minor typos in the documentation: no need to update your
copy, but while I was doing maintenance I went ahead and fixed these.

Bruce Sherwood

Re: [Visualpython-users] installation success on Debian3.0-i386, and a hello

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

Many thanks for the helpful comments on installing VPython on Debian. When I
get my act together, I'll post these comments on the VPython web site.

Concerning how VPython is being used: I know of several different kinds of
uses.

Some scientists and engineers use it in their research to visualize data.
Sometimes the data come from some other program (C, Fortran) but get looked
at in 3D in VPython. While there are various 3D data visualization packages,
there is often an advantage to being able to write a custom 3D data display
under the flexible control of a programming language, hence the research
value of VPython.

Sometimes intro programming course use Python as the language, which is a
good choice for introducing the elements of programming, including
object-oriented programming. I know of at least one case where VPython is
used in such a course, because it is more motivating to make 3D animations
than to print tables of Fibonacci numbers. VPython also helps enormously in
getting across the notion of an object (since the object has a striking
visual representation), attributes, etc.

As you guessed, some instructors especially in physics use VPython to create
3D visualization to show in class as lecture demos. There are examples of
this in the demo suite that comes with VPython, and in the set of demos for
intro physics available at http://www4.ncsu.edu/~rwchabay/mi.

In a modern introductory physics curriculum developed by Ruth Chabay and me
(Matter & Interactions; see previous URL), students themselves write VPython
programs to model physical systems and to visualize electric and magnetic
fields in 3D. Computer modeling is a central aspect of our textbook. This
new curriculum is in use at a number of colleges and universities.

In the University of Maryland physics department Ellen Williams teaches a
computational physics course in which students write VPython programs.

Bruce Sherwood

----- Original Message -----
From: "gelfand" <ge...@la...>
To: <vis...@li...>
Sent: Friday, October 11, 2002 6:34 PM
Subject: [Visualpython-users] installation success on Debian3.0-i386, and a
hello


> I started playing with vpython a week or two ago, and since I
> noticed that many of the posts on this list concern
> platform-specific problems I thought I'd report some details
> of a straightforward success.
>
> CPU is a Celeron 300A, video a Matrox G100.
>
> With Debian 3.0, the following packages should be installed
> in order to run visual python (if this ever becomes an
> official Debian package, it should be called python2.2-visual)
>
> python2.2
> python2.2-numeric
> python2.2-numeric-ext
> python2.2-tk
> xlibmesa3
> libgtk1.2
> libglib1.2
> gtkglarea5
>
> as well as glibc and the c++ standard libraries which are almost
> certainly on the system already.
>
> If you want to compile cvisualmodule.so you'll need the development
> packages gtkglarea-dev, python2.2-dev, xlibmesa-dev, libgtk1.2-dev,
> libglib1.2-dev --- but if anyone is interested I can supply the
> compiled module and save you the trouble.  If I can find the time
> to learn how to make a Debian package I'll roll one.
>
> The only "issues" I've encountered concern cursor-hiding (apparently
> not implemented in the GL library) and program killing (closing
> one or more of the display windows doesn't always do the trick,
> sometimes I have to ctrl-z in the shell and then kill -9 %1;
> sys.exit() in the code doesn't work, though os._exit(0) will do the
> trick).
>
> On another note, I'm wondering how folks are using vpython-based
> programs:  "virtual" demonstrations in classes? part of
> laboratory work?  student assignments?  Is there a venue other than
> this to discuss applications?
>
> Finally, thanks to the authors/contributors for a nice piece of software!
>
> --Marty
>
> Martin Gelfand
>
> Associate Professor.............Phone: 970 491 5263
> Department of Physics.............Fax: 970 491 7947
> Colorado State University.......Email: ge...@la...
> Fort Collins CO 80523-1875
>
>
>
> -------------------------------------------------------
> This sf.net email is sponsored by:ThinkGeek
> Welcome to geek heaven.
> http://thinkgeek.com/sf
> _______________________________________________
> Visualpython-users mailing list
> Vis...@li...
> https://lists.sourceforge.net/lists/listinfo/visualpython-users
>

[Visualpython-users] installation success on Debian3.0-i386, and a hello

[gelfand <ge...@la...>]

I started playing with vpython a week or two ago, and since I
noticed that many of the posts on this list concern
platform-specific problems I thought I'd report some details
of a straightforward success.

CPU is a Celeron 300A, video a Matrox G100.

With Debian 3.0, the following packages should be installed
in order to run visual python (if this ever becomes an
official Debian package, it should be called python2.2-visual)

python2.2
python2.2-numeric
python2.2-numeric-ext
python2.2-tk
xlibmesa3
libgtk1.2
libglib1.2
gtkglarea5

as well as glibc and the c++ standard libraries which are almost
certainly on the system already.

If you want to compile cvisualmodule.so you'll need the development
packages gtkglarea-dev, python2.2-dev, xlibmesa-dev, libgtk1.2-dev,
libglib1.2-dev --- but if anyone is interested I can supply the
compiled module and save you the trouble.  If I can find the time
to learn how to make a Debian package I'll roll one.

The only "issues" I've encountered concern cursor-hiding (apparently
not implemented in the GL library) and program killing (closing
one or more of the display windows doesn't always do the trick,
sometimes I have to ctrl-z in the shell and then kill -9 %1;
sys.exit() in the code doesn't work, though os._exit(0) will do the
trick).

On another note, I'm wondering how folks are using vpython-based
programs:  "virtual" demonstrations in classes? part of
laboratory work?  student assignments?  Is there a venue other than
this to discuss applications?

Finally, thanks to the authors/contributors for a nice piece of software!

--Marty

Martin Gelfand

Associate Professor.............Phone: 970 491 5263
Department of Physics.............Fax: 970 491 7947
Colorado State University.......Email: ge...@la...
Fort Collins CO 80523-1875

Re: [Visualpython-users] Segmentation Fault under RH 7.2

[Kevin C. <kj...@gr...>]

Not a direct answer to your question, but of possible interest:  It
appears that Red Hat 8.0 has FINALLY decided to switch everything to=20
Python 2.2, and has symbolic links between "python", "python2" and=20
some other variant ("python2.2" I think). So some of the reason for
sticking with both 1.5.2 and 2.x has gone away.

On Tue, Oct 08, 2002 at 09:52:31AM -0400, Mike Mellor wrote:

> I am trying to get VPython running on my RedHat 7.2 system.  I have=20
> python 2.2.1 installed from rpm as python2 (I can't get rid of python=20
> 1.5.2, so it has to be python2).  I made the corrections to the install=
=20
> script and the cvisual Makefile.  It appears to install, but I get a=20
> segmentation fault when I run python scripts with VPython modules.  What=
=20
> appears to happen is that the script runs, I get the VPython message,=20
> but then it segmentation faults when it goes to graph.  Running scripts=
=20
> from the VPython IDLE doesn't seem to do anything (I'm guessing that it=
=20
> isn't showing the seg fault).

--=20
 Kevin Cole, RHCE, Linux Admin  |  Key ID:  0xE6F332C7
 Gallaudet Research Institute   |  WWW:     http://gri.gallaudet.edu/~kjcol=
e/
 Hall Memorial Bldg  S-419      |  Voice:   (202) 651-5135
 Washington, D.C.  20002-3695   |  FAX:     (202) 651-5746

[Visualpython-users] Segmentation Fault under RH 7.2

[Mike M. <mme...@ya...>]

Hello -

I am trying to get VPython running on my RedHat 7.2 system.  I have 
python 2.2.1 installed from rpm as python2 (I can't get rid of python 
1.5.2, so it has to be python2).  I made the corrections to the install 
script and the cvisual Makefile.  It appears to install, but I get a 
segmentation fault when I run python scripts with VPython modules.  What 
appears to happen is that the script runs, I get the VPython message, 
but then it segmentation faults when it goes to graph.  Running scripts 
from the VPython IDLE doesn't seem to do anything (I'm guessing that it 
isn't showing the seg fault).

The video card is a TrioV64, XFree86 4.1, Mesa is installed, Glide_V2 is 
installed.  My computer is a 200MHz pentium with 48M RAM.  

Any idea what I need to do to get this working?

Thanks.

Mike

Re: [Visualpython-users] Errors running Vpython on OSX

[Steve S. <st...@sp...>]

I worked on sorting this out for a bit (I'm sure all my messages are 
still floating around the numericalpython/python/fink mailing lists.. 
), but I didn't have time to actually figure out what was going on. I 
did find that errno was getting set somehow, but it didn't appear to 
reflect an actual numerical problem, but rather resolved to 'resource 
temporarily unavailable". I'm gussing it's something to do with the way 
idle handles multi-threaded programs, that doesn't work with command 
line python on its own. But.. it's just a guess!

-steve

On Monday, October 7, 2002, at 12:12  PM, Bruce Sherwood wrote:

> I vaguely remember Steve Spicklemire finding an arcane problem with the
> Numeric module on Mac OSX, that was never resolved and which sounds 
> somewhat
> related. Obviously the run environment shouldn't matter. Steve, do you 
> think
> there's some kind of connection here?
>
> Bruce
>
> ----- Original Message -----
> From: "Chris Burns" <bu...@hv...>
> To: "Steve Spicklemire" <st...@sp...>
> Cc: <vis...@li...>
> Sent: Monday, October 07, 2002 11:50 AM
> Subject: Re: [Visualpython-users] Errors running Vpython on OSX
>
>
>> Hi all.
>>
>>> This sounds like the problem I saw when trying to run outside the 
>>> Idle
>>> environment. Are you running inside Idle?
>>
>> Aha!  That's the ticket.  It works fine inside idle.  I actually tried
>> idle the first time, but it turns out I was using the wrong one.  
>> Python
>> comes with it's own idle in /sw/bin (which was first in the path, 
>> before
>> /usr/local/bin/idle).  Thanks!  Now I can show my students all the 
>> nifty
>> things we can do.
>>
>> So what's so special about the idle environment?  I thought it was 
>> just
>> window dressing for the python interpreter.  I'm a command-line
>> enthusiast (and I edit my programs in vi), so I prefer just running 
>> from
>> the shell, which works fine in Linux.  Just curious why OS X is so
>> different.
>>
>> Chris
>

Re: [Visualpython-users] Errors running Vpython on OSX

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

I vaguely remember Steve Spicklemire finding an arcane problem with the
Numeric module on Mac OSX, that was never resolved and which sounds somewhat
related. Obviously the run environment shouldn't matter. Steve, do you think
there's some kind of connection here?

Bruce

----- Original Message -----
From: "Chris Burns" <bu...@hv...>
To: "Steve Spicklemire" <st...@sp...>
Cc: <vis...@li...>
Sent: Monday, October 07, 2002 11:50 AM
Subject: Re: [Visualpython-users] Errors running Vpython on OSX


> Hi all.
>
> > This sounds like the problem I saw when trying to run outside the Idle
> > environment. Are you running inside Idle?
>
> Aha!  That's the ticket.  It works fine inside idle.  I actually tried
> idle the first time, but it turns out I was using the wrong one.  Python
> comes with it's own idle in /sw/bin (which was first in the path, before
> /usr/local/bin/idle).  Thanks!  Now I can show my students all the nifty
> things we can do.
>
> So what's so special about the idle environment?  I thought it was just
> window dressing for the python interpreter.  I'm a command-line
> enthusiast (and I edit my programs in vi), so I prefer just running from
> the shell, which works fine in Linux.  Just curious why OS X is so
> different.
>
> Chris

Re: [Visualpython-users] Errors running Vpython on OSX

[Chris B. <bu...@hv...>]

Hi all.

> This sounds like the problem I saw when trying to run outside the Idle 
> environment. Are you running inside Idle?

Aha!  That's the ticket.  It works fine inside idle.  I actually tried
idle the first time, but it turns out I was using the wrong one.  Python
comes with it's own idle in /sw/bin (which was first in the path, before
/usr/local/bin/idle).  Thanks!  Now I can show my students all the nifty
things we can do.

So what's so special about the idle environment?  I thought it was just
window dressing for the python interpreter.  I'm a command-line 
enthusiast (and I edit my programs in vi), so I prefer just running from
the shell, which works fine in Linux.  Just curious why OS X is so 
different.

Chris

> 
> -steve
> 
> On Friday, October 4, 2002, at 04:19  PM, Chris Burns wrote:
> 
> > Hi all.
> >
> > Thanks for the quick reply!  To clarify, the script I ran was the 
> > standard
> > doublependulum.py that ships with the software.  It works fine on my 
> > Linux
> > computer (as well as other scripts I've written).  I've tried 
> > installing
> > VPython on two seperate Macs and get the same behaviour on both.  
> > Details:
> >
> >   - Mac OSX 10.1.5
> >   - python 2.2.1 installed using fink version 0.4.1
> >   - Installed VPython (Visual-2002-07-22) using the install script
> >
> > Regarding the theta1 suggestion, the script sometimes bombs even before
> > the pendulum completes an oscillation, so I don't think it's a problem 
> > with
> > theta becoming too large.  It does seem to have something to do with 
> > the
> > number of computations, though.  I wrote a double-pendulum of my own 
> > with
> > Runga-Kutta and it consistently dies more quickly.
> >
> > Unfortunately, I don't maintain the Mac's, I just installed fink to get
> > python working, so I don't know if there might be some esoteric 
> > software
> > that might interfere.  But fink seems to make its own little world 
> > below
> > /sw, so I don't see how there could be a conflict.
> >
> > I also tried installing python from source (ie., not using fink) and I 
> > get
> > the same problem.
> >
> > Chris
> >
> >> doublependulum.py is part of the standard VPython demo suite. All the 
> >> demos
> >> work on other OSX machines.
> >>
> >> Bruce Sherwood
> >>
> >> ----- Original Message -----
> >> From: "Andy Dougherty" <dou...@la...>
> >> To: "Bruce Sherwood" <bas...@un...>
> >> Cc: "Andy Dougherty" <dou...@ma...>;
> >> <cb...@sw...>; <vis...@li...>
> >> Sent: Friday, October 04, 2002 3:20 PM
> >> Subject: Re: [Visualpython-users] Errors running Vpython on OSX
> >>
> >>
> >>> On Fri, 4 Oct 2002, Bruce Sherwood wrote:
> >>>
> >>>> This vague possibility would seem to be ruled out by the fact that 
> >>>> these
> >>>> programs run on other people's Mac OSX machines, with presumably the
> >> same
> >>>> math libraries, no?
> >>>
> >>> Not quite, unless I've misunderstood the original poster's question.
> >>> Yes, Vpython runs fine on other people's Mac OS X machines, but I'm
> >>> unclear if this particular script runs fine on other people's Mac OS 
> >>> X
> >>> machines.
> >>>
> >>>>>> Traceback (most recent call last):
> >>>>>>   File "doublependulum.py", line 71, in ?
> >>>>>>     atheta2 = -(A*atheta1+C*sin(theta1))/B
> >>>>>> ValueError: unexpected math error
> >>>
> >>> What I'm imagining is that the user is simulating a (possibly damped,
> >>> driven) double pendulum that might have swung over many many times, 
> >>> so
> >>> that theta1 and/or theta2 might be very large compared to 2 pi.  
> >>> That's
> >>> the sort of thing I've seen eventually lead to odd problems 
> >>> elsewhere.
> >>>
> >>> Perhaps if the original script were posted, others could test it.
> >>>
> >>> --
> >>>     Andy Dougherty dou...@la...
> >>>     Dept. of Physics
> >>>     Lafayette College, Easton PA 18042
> >>>
> >>>
> >>
> >>
> >
> >
> >
> > -------------------------------------------------------
> > This sf.net email is sponsored by:ThinkGeek
> > Welcome to geek heaven.
> > http://thinkgeek.com/sf
> > _______________________________________________
> > Visualpython-users mailing list
> > Vis...@li...
> > https://lists.sourceforge.net/lists/listinfo/visualpython-users
> 
> 

Re: [Visualpython-users] Errors running Vpython on OSX

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

On Fri, 4 Oct 2002, Chris Burns wrote:

> Thanks for the quick reply!  To clarify, the script I ran was the standard
> doublependulum.py that ships with the software.

> Regarding the theta1 suggestion, the script sometimes bombs even before
> the pendulum completes an oscillation, so I don't think it's a problem with
> theta becoming too large.

Well, that's where my theory falls to the ground.  I was hoping we
could take the 'Math Error' message at face value.  Rats.

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

Re: [Visualpython-users] Errors running Vpython on OSX

[Steve S. <st...@sp...>]

This sounds like the problem I saw when trying to run outside the Idle 
environment. Are you running inside Idle?

-steve

On Friday, October 4, 2002, at 04:19  PM, Chris Burns wrote:

> Hi all.
>
> Thanks for the quick reply!  To clarify, the script I ran was the 
> standard
> doublependulum.py that ships with the software.  It works fine on my 
> Linux
> computer (as well as other scripts I've written).  I've tried 
> installing
> VPython on two seperate Macs and get the same behaviour on both.  
> Details:
>
>   - Mac OSX 10.1.5
>   - python 2.2.1 installed using fink version 0.4.1
>   - Installed VPython (Visual-2002-07-22) using the install script
>
> Regarding the theta1 suggestion, the script sometimes bombs even before
> the pendulum completes an oscillation, so I don't think it's a problem 
> with
> theta becoming too large.  It does seem to have something to do with 
> the
> number of computations, though.  I wrote a double-pendulum of my own 
> with
> Runga-Kutta and it consistently dies more quickly.
>
> Unfortunately, I don't maintain the Mac's, I just installed fink to get
> python working, so I don't know if there might be some esoteric 
> software
> that might interfere.  But fink seems to make its own little world 
> below
> /sw, so I don't see how there could be a conflict.
>
> I also tried installing python from source (ie., not using fink) and I 
> get
> the same problem.
>
> Chris
>
>> doublependulum.py is part of the standard VPython demo suite. All the 
>> demos
>> work on other OSX machines.
>>
>> Bruce Sherwood
>>
>> ----- Original Message -----
>> From: "Andy Dougherty" <dou...@la...>
>> To: "Bruce Sherwood" <bas...@un...>
>> Cc: "Andy Dougherty" <dou...@ma...>;
>> <cb...@sw...>; <vis...@li...>
>> Sent: Friday, October 04, 2002 3:20 PM
>> Subject: Re: [Visualpython-users] Errors running Vpython on OSX
>>
>>
>>> On Fri, 4 Oct 2002, Bruce Sherwood wrote:
>>>
>>>> This vague possibility would seem to be ruled out by the fact that 
>>>> these
>>>> programs run on other people's Mac OSX machines, with presumably the
>> same
>>>> math libraries, no?
>>>
>>> Not quite, unless I've misunderstood the original poster's question.
>>> Yes, Vpython runs fine on other people's Mac OS X machines, but I'm
>>> unclear if this particular script runs fine on other people's Mac OS 
>>> X
>>> machines.
>>>
>>>>>> Traceback (most recent call last):
>>>>>>   File "doublependulum.py", line 71, in ?
>>>>>>     atheta2 = -(A*atheta1+C*sin(theta1))/B
>>>>>> ValueError: unexpected math error
>>>
>>> What I'm imagining is that the user is simulating a (possibly damped,
>>> driven) double pendulum that might have swung over many many times, 
>>> so
>>> that theta1 and/or theta2 might be very large compared to 2 pi.  
>>> That's
>>> the sort of thing I've seen eventually lead to odd problems 
>>> elsewhere.
>>>
>>> Perhaps if the original script were posted, others could test it.
>>>
>>> --
>>>     Andy Dougherty dou...@la...
>>>     Dept. of Physics
>>>     Lafayette College, Easton PA 18042
>>>
>>>
>>
>>
>
>
>
> -------------------------------------------------------
> This sf.net email is sponsored by:ThinkGeek
> Welcome to geek heaven.
> http://thinkgeek.com/sf
> _______________________________________________
> Visualpython-users mailing list
> Vis...@li...
> https://lists.sourceforge.net/lists/listinfo/visualpython-users

Re: [Visualpython-users] Re: strange output

[Arthur <aj...@ix...>]

I feared in the back of my mind, my answer posted this morning is dead
wrong.  My answer had assumed
that ball.pos could be treated as a normal Python list Which is not the
case. It is of type "vector", which is not a native Python type, but one
coming over from the cvisual code.  As such it turns out it is neither
sliceable or copyable.

The *right* answer here seems to be:

rinitial=list(ball.pos)
or
rinitial=tuple(ball.pos)

This stores rinital in a separate object not effected by changes in
ball.pos, but which can work for
ball.pos=rinital
should one want to restore the initial position of ball.

I think.

Sorry for the misinfo.

Art



>I think it worth supplementing Bruce's analysis with the solution to what
was trying to be accomplished by

>rininitial = ball.pos

>I believe either:

>rinitial = ball.pos[:]

>or

>rinitial =copy(ball.pos)

>would get one to where one is trying to go.

>[:] returns a complete "slice" of the list.
>copy, of course, a copy of the list.

>In either case rinitial is no longer an additional name for ball.pos, but
an
>object independant of it, which will not be modified upon the modification
>of ball.pos.

>I think I have this right.  Corrections welcome.

>Art