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Vectors

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  Vectors Algis Kabaila <akabaila@pcug.org.au> - 2011-04-20 17:47 +1000
    Re: Vectors Anssi Saari <as@sci.fi> - 2011-04-20 11:07 +0300
      RE: Vectors Andreas Tawn <andreas.tawn@ubisoft.com> - 2011-04-20 15:43 +0200
        Re: Vectors RJB <rbotting@csusb.edu> - 2011-04-20 08:34 -0700
          RE: Vectors Andreas Tawn <andreas.tawn@ubisoft.com> - 2011-04-20 17:49 +0200
          Re: Vectors Algis Kabaila <akabaila@pcug.org.au> - 2011-04-21 17:25 +1000
            Re: Vectors Gregory Ewing <greg.ewing@canterbury.ac.nz> - 2011-04-22 13:43 +1200
              Re: Vectors Algis Kabaila <akabaila@pcug.org.au> - 2011-04-22 20:58 +1000
        Re: Vectors Anssi Saari <as@sci.fi> - 2011-04-21 17:07 +0300
        Re: Vectors Jonathan Hartley <tartley@tartley.com> - 2011-04-25 03:49 -0700
          Re: Vectors Algis Kabaila <akabaila@pcug.org.au> - 2011-04-26 21:26 +1000
    Re: Vectors sturlamolden <sturlamolden@yahoo.no> - 2011-04-22 13:57 -0700
      Re: Vectors Algis Kabaila <akabaila@pcug.org.au> - 2011-04-23 10:32 +1000
        Re: Vectors sturlamolden <sturlamolden@yahoo.no> - 2011-04-22 21:13 -0700
          Re: Vectors Algis Kabaila <akabaila@pcug.org.au> - 2011-04-23 22:26 +1000
            Re: Vectors sturlamolden <sturlamolden@yahoo.no> - 2011-04-23 07:02 -0700
      Re: Vectors Robert Kern <robert.kern@gmail.com> - 2011-04-24 18:49 -0500
        Re: Vectors rusi <rustompmody@gmail.com> - 2011-04-24 19:59 -0700
          Re: Vectors Algis Kabaila <akabaila@pcug.org.au> - 2011-04-25 17:05 +1000

#3663 — Vectors

Hi,

Are there any modules for vector algebra (three dimensional 
vectors, vector addition, subtraction, multiplication [scalar 
and vector]. Could you give me a reference to such module?

platform - ubuntu 10.10 (Linux), Python 3.1 or higher.

Thanks for your help to avoid re-invention of the wheel.

OldAl.

-- 
Algis
http://akabaila.pcug.org.au/StructuralAnalysis.pdf

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#3666

Algis Kabaila <akabaila@pcug.org.au> writes:

> Are there any modules for vector algebra (three dimensional 
> vectors, vector addition, subtraction, multiplication [scalar 
> and vector]. Could you give me a reference to such module?

NumPy has array (and matrix) types with support for these basic
operations you mention. See the tutorial at http://numpy.scipy.org/

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#3702

> Algis Kabaila <akabaila@pcug.org.au> writes:
> 
> > Are there any modules for vector algebra (three dimensional
> > vectors, vector addition, subtraction, multiplication [scalar
> > and vector]. Could you give me a reference to such module?
> 
> NumPy has array (and matrix) types with support for these basic
> operations you mention. See the tutorial at http://numpy.scipy.org/

You might also want to consider http://code.google.com/p/pyeuclid/

Cheers,

Drea

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#3721

On Apr 20, 6:43 am, Andreas Tawn <andreas.t...@ubisoft.com> wrote:
> > Algis Kabaila <akaba...@pcug.org.au> writes:
>
> > > Are there any modules for vector algebra (three dimensional
> > > vectors, vector addition, subtraction, multiplication [scalar
> > > and vector]. Could you give me a reference to such module?
>
> > NumPy has array (and matrix) types with support for these basic
> > operations you mention. See the tutorial athttp://numpy.scipy.org/
>
> You might also want to considerhttp://code.google.com/p/pyeuclid/
>
> Cheers,
>
> Drea

Pyeuclid docs don't mention dot or cross products.
RJB

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#3725

> On Apr 20, 6:43 am, Andreas Tawn <andreas.t...@ubisoft.com> wrote:
> > > Algis Kabaila <akaba...@pcug.org.au> writes:
> >
> > > > Are there any modules for vector algebra (three dimensional
> > > > vectors, vector addition, subtraction, multiplication [scalar
> > > > and vector]. Could you give me a reference to such module?
> >
> > > NumPy has array (and matrix) types with support for these basic
> > > operations you mention. See the tutorial athttp://numpy.scipy.org/
> >
> > You might also want to considerhttp://code.google.com/p/pyeuclid/
> >
> > Cheers,
> >
> > Drea
> 
> Pyeuclid docs don't mention dot or cross products.
> RJB

http://partiallydisassembled.net/euclid/vector-classes.html#SECTION002220000000000000000

Bottom of the page.

Cheers,

Drea

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#3771

On Thursday 21 April 2011 01:49:57 Andreas Tawn wrote:
> > On Apr 20, 6:43 am, Andreas Tawn <andreas.t...@ubisoft.com> 
wrote:
> > > > Algis Kabaila <akaba...@pcug.org.au> writes:
> > > > > Are there any modules for vector algebra (three
> > > > > dimensional vectors, vector addition, subtraction,
> > > > > multiplication [scalar and vector]. Could you give
> > > > > me a reference to such module?
> > > > 
> > > > NumPy has array (and matrix) types with support for
> > > > these basic operations you mention. See the tutorial
> > > > athttp://numpy.scipy.org/
> > > 
> > > You might also want to
> > > considerhttp://code.google.com/p/pyeuclid/
> > > 
> > > Cheers,
> > > 
> > > Drea
> > 
> > Pyeuclid docs don't mention dot or cross products.
> > RJB
> 
> http://partiallydisassembled.net/euclid/vector-classes.html#S
> ECTION002220000000000000000
> 
> Bottom of the page.
> 
> Cheers,
> 
> Drea

Yes, pyeuclid had "cross" and "dot" product of vectors. I am 
impressed with it and curious how it works:  the Vector3 class 
is available without any prefix euclid:

import euclid 
v = Vector3(111.., 222.2, 333.3)

works without  requiring as in:
v = euclid.Vector3( etc...)

I am really intrigued by that. OTOH, I also am somewhat 
aprehensive about using something that affects the program 
writing after importing "euclid", without any need to explicitly 
refer to euclid.  Looks rather risky to me.  What does that do 
to the namespace?

Thanks for bringing this to my attention.  I confess that I 
would be hapier if euclid was accessible in a "standard" manner 
with prefix of module name for classes in the module.

OldAl.

-- 
Algis
http://akabaila.pcug.org.au/StructuralAnalysis.pdf

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#3834

Algis Kabaila wrote:
> the Vector3 class 
> is available without any prefix euclid:
> 
> import euclid 
> v = Vector3(111.., 222.2, 333.3)

Doesn't work that way for me:

Python 2.7 (r27:82500, Oct 15 2010, 21:14:33)
[GCC 4.2.1 (Apple Inc. build 5664)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
 >>> import euclid
 >>> Vector3
Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
NameError: name 'Vector3' is not defined

Are you sure you hadn't previously done 'from euclid import
Vector3' or 'from euclid import *' in that session?

-- 
Greg

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#3859

On Friday 22 April 2011 11:43:26 Gregory Ewing wrote:
> Algis Kabaila wrote:
> > the Vector3 class
> > is available without any prefix euclid:
> > 
> > import euclid
> > v = Vector3(111.., 222.2, 333.3)
> 
> Doesn't work that way for me:
> 
> Python 2.7 (r27:82500, Oct 15 2010, 21:14:33)
> [GCC 4.2.1 (Apple Inc. build 5664)] on darwin
> Type "help", "copyright", "credits" or "license" for more
> information.
> 
>  >>> import euclid
>  >>> Vector3
> 
> Traceback (most recent call last):
>    File "<stdin>", line 1, in <module>
> NameError: name 'Vector3' is not defined
> 
> Are you sure you hadn't previously done 'from euclid import
> Vector3' or 'from euclid import *' in that session?

I've tested it again and it does behave in a "standard" manner.  
I must have imported all as you suspected. Makes me much 
happier, though I do feel sheepish.  As they say, sh... happens.

BTW, I did modify the euclid very slightly to work with Python 3 
- just change the syntax of messages with exception in line with 
syntax changes.

Thanks for sharing your experience with that cute package!

OldAl.
-- 
Algis
http://akabaila.pcug.org.au/StructuralAnalysis.pdf

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#3798

Andreas Tawn <andreas.tawn@ubisoft.com> writes:

> You might also want to consider http://code.google.com/p/pyeuclid/

Thanks, I was studying quaternions recently and had to use two
packages to get some stuff done. And of course one of them used
ass-backwards declaration for a quaternion and one didn't...

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#3972

On Apr 20, 2:43 pm, Andreas Tawn <andreas.t...@ubisoft.com> wrote:
> > Algis Kabaila <akaba...@pcug.org.au> writes:
>
> > > Are there any modules for vector algebra (three dimensional
> > > vectors, vector addition, subtraction, multiplication [scalar
> > > and vector]. Could you give me a reference to such module?
>
> > NumPy has array (and matrix) types with support for these basic
> > operations you mention. See the tutorial athttp://numpy.scipy.org/
>
> You might also want to considerhttp://code.google.com/p/pyeuclid/
>
> Cheers,
>
> Drea


Stealing this from Casey Duncan's recent post to the Grease users
list:


- (ab)use complex numbers for 2D vectors (only). Very fast arithmetic
and built-in to Python. Downside is lack of abstraction.

- Use pyeuclid (pure python) if ultimate speed isn't an issue, or if
compiled extensions are. It supports 3D and has a nice api

- vectypes is a more recent project from the same author as pyeuclid.
It offers a more consistent 'GLSL' like interface, including
swizzling, and internally seems to have more maintainable code because
it generates various sizes of vector and matrix from a single
template. This is done without performance penalty because the
generation is done at design time, not runtime.

- Use pyeigen if you want fast vectors, and don't mind compiling some
C/C++. I don't know how the Python api looks though

- Use numpy if you want fast batch operations

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#4033

On Monday 25 April 2011 20:49:34 Jonathan Hartley wrote:
> On Apr 20, 2:43 pm, Andreas Tawn <andreas.t...@ubisoft.com> 
wrote:
> > > Algis Kabaila <akaba...@pcug.org.au> writes:
> > > > Are there any modules for vector algebra (three
> > > > dimensional vectors, vector addition, subtraction,
> > > > multiplication [scalar and vector]. Could you give me
> > > > a reference to such module?
> > > 
> > > NumPy has array (and matrix) types with support for these
> > > basic operations you mention. See the tutorial
> > > athttp://numpy.scipy.org/
> > 
> > You might also want to
> > considerhttp://code.google.com/p/pyeuclid/
> > 
> > Cheers,
> > 
> > Drea
> 
> Stealing this from Casey Duncan's recent post to the Grease
> users list:
> 
> 
> - (ab)use complex numbers for 2D vectors (only). Very fast
> arithmetic and built-in to Python. Downside is lack of
> abstraction.
> 
> - Use pyeuclid (pure python) if ultimate speed isn't an
> issue, or if compiled extensions are. It supports 3D and has
> a nice api
> 
> - vectypes is a more recent project from the same author as
> pyeuclid. It offers a more consistent 'GLSL' like interface,
> including swizzling, and internally seems to have more
> maintainable code because it generates various sizes of
> vector and matrix from a single template. This is done
> without performance penalty because the generation is done
> at design time, not runtime.
> 
> - Use pyeigen if you want fast vectors, and don't mind
> compiling some C/C++. I don't know how the Python api looks
> though
> 
> - Use numpy if you want fast batch operations
Jonathan,

Thank you for a nice and extensive list of references. To 
clarify my position - surprisingly, speed is not an issue- I've 
programmed a matrix in pure python (3, but mainly iwth python 2 
syntax) and found that inversion was quite fast enough for my 
requirements.  

Good vector algebra is necessary for 3 D frame analysis, so a 
vector package is indicated.  numpy is great, but it is a tool 
like a sledge to drive a nail...

OldAl.
-- 
Algis
http://akabaila.pcug.org.au/StructuralAnalysis.pdf

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#3893

On Apr 20, 9:47 am, Algis Kabaila <akaba...@pcug.org.au> wrote:

> Are there any modules for vector algebra (three dimensional
> vectors, vector addition, subtraction, multiplication [scalar
> and vector]. Could you give me a reference to such module?

NumPy

Or one of these libraries (ctypes or Cython):

BLAS (Intel MKL, ACML, ACML-GPU, GotoBLAS2, or ATLAS)
Intel VML
ACML-VM

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#3899

On Saturday 23 April 2011 06:57:23 sturlamolden wrote:
> On Apr 20, 9:47 am, Algis Kabaila <akaba...@pcug.org.au> 
wrote:
> > Are there any modules for vector algebra (three dimensional
> > vectors, vector addition, subtraction, multiplication
> > [scalar and vector]. Could you give me a reference to such
> > module?
> 
> NumPy
> 
> Or one of these libraries (ctypes or Cython):
> 
> BLAS (Intel MKL, ACML, ACML-GPU, GotoBLAS2, or ATLAS)
> Intel VML
> ACML-VM

Thanks for that.  Last time I looked at numpy (for Python3) it 
was available in source only.  I know, real men do compile, but 
I am an old man...  I will compile if it is unavoidable, but in 
case of numpy it does not seem  a simple matter. Am I badly 
mistaken?

euclid has another attraction - the source is readily available, 
not too burdened by backward compatibility issues and relatively 
easy to follow, though I "managed" to get lost in it   :)

OldAl.
-- 
Algis
http://akabaila.pcug.org.au/StructuralAnalysis.pdf

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#3902

On Apr 23, 2:32 am, Algis Kabaila <akaba...@pcug.org.au> wrote:

> Thanks for that.  Last time I looked at numpy (for Python3) it
> was available in source only.  I know, real men do compile, but
> I am an old man...  I will compile if it is unavoidable, but in
> case of numpy it does not seem  a simple matter. Am I badly
> mistaken?


There is a Win32 binary for Python 3.1:

http://sourceforge.net/projects/numpy/files/NumPy/1.5.1/

I have not tried to compile NumPy as I use Enthought to
avoid such headaches. I value my own time enough to pay
for a subscription ;-)

http://enthought.com/



Sturla

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#3908

On Saturday 23 April 2011 14:13:31 sturlamolden wrote:
> On Apr 23, 2:32 am, Algis Kabaila <akaba...@pcug.org.au> 
wrote:
> > Thanks for that.  Last time I looked at numpy (for Python3)
> > it was available in source only.  I know, real men do
> > compile, but I am an old man...  I will compile if it is
> > unavoidable, but in case of numpy it does not seem  a
> > simple matter. Am I badly mistaken?
> 
> There is a Win32 binary for Python 3.1:
> 
> http://sourceforge.net/projects/numpy/files/NumPy/1.5.1/
> 
> I have not tried to compile NumPy as I use Enthought to
> avoid such headaches. I value my own time enough to pay
> for a subscription ;-)
> 
> http://enthought.com/
> 
> 
> 
> Sturla

Whilst I have Win32 officially paid for OS, never "fire it up".  
I find nix systems much more interesting and convenient for 
programming and  consequently I use ubuntu for computing 
activities.  I do understand that many people prefer Win32 and 
appreciate their right to use what they want.  I just am at a 
loss to understand *why* ...

I guess each to own taste,

OldAl.
-- 
Algis
http://akabaila.pcug.org.au/StructuralAnalysis.pdf

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#3912

On Apr 23, 2:26 pm, Algis Kabaila <akaba...@pcug.org.au> wrote:

> I do understand that many people prefer Win32 and
> appreciate their right to use what they want.  I just am at a
> loss to understand *why* ...

For the same reason some people prefered OS/2 or
DEC to SunOS or BSD.

For the same reason some people prefer Perl or Java
to Python.

Sturla

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#3966

On 4/22/11 7:32 PM, Algis Kabaila wrote:
> On Saturday 23 April 2011 06:57:23 sturlamolden wrote:
>> On Apr 20, 9:47 am, Algis Kabaila<akaba...@pcug.org.au>
> wrote:
>>> Are there any modules for vector algebra (three dimensional
>>> vectors, vector addition, subtraction, multiplication
>>> [scalar and vector]. Could you give me a reference to such
>>> module?
>>
>> NumPy
>>
>> Or one of these libraries (ctypes or Cython):
>>
>> BLAS (Intel MKL, ACML, ACML-GPU, GotoBLAS2, or ATLAS)
>> Intel VML
>> ACML-VM
>
> Thanks for that.  Last time I looked at numpy (for Python3) it
> was available in source only.  I know, real men do compile, but
> I am an old man...  I will compile if it is unavoidable, but in
> case of numpy it does not seem  a simple matter. Am I badly
> mistaken?

On UNIX machines with compilers and headers properly installed, it's really 
pretty straightforward.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco

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#3968

On Apr 25, 4:49 am, Robert Kern <robert.k...@gmail.com> wrote:
> On 4/22/11 7:32 PM, Algis Kabaila wrote:
>
>
>
> > On Saturday 23 April 2011 06:57:23 sturlamolden wrote:
> >> On Apr 20, 9:47 am, Algis Kabaila<akaba...@pcug.org.au>
> > wrote:
> >>> Are there any modules for vector algebra (three dimensional
> >>> vectors, vector addition, subtraction, multiplication
> >>> [scalar and vector]. Could you give me a reference to such
> >>> module?
>
> >> NumPy
>
> >> Or one of these libraries (ctypes or Cython):
>
> >> BLAS (Intel MKL, ACML, ACML-GPU, GotoBLAS2, or ATLAS)
> >> Intel VML
> >> ACML-VM
>
> > Thanks for that.  Last time I looked at numpy (for Python3) it
> > was available in source only.  I know, real men do compile, but
> > I am an old man...  I will compile if it is unavoidable, but in
> > case of numpy it does not seem  a simple matter. Am I badly
> > mistaken?
>
> On UNIX machines with compilers and headers properly installed, it's really
> pretty straightforward.

Mostly (on ubuntu/debian) that means do this [Untested]
$ aptitude build-dep python-numpy
Then you should be ready to build/compile numpy from source

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#3971

On Monday 25 April 2011 12:59:38 rusi wrote:
> On Apr 25, 4:49 am, Robert Kern <robert.k...@gmail.com> wrote:
> > On 4/22/11 7:32 PM, Algis Kabaila wrote:
> > > On Saturday 23 April 2011 06:57:23 sturlamolden wrote:
> > >> On Apr 20, 9:47 am, Algis Kabaila<akaba...@pcug.org.au>
> > > 
> > > wrote:
> > >>> Are there any modules for vector algebra (three
> > >>> dimensional vectors, vector addition, subtraction,
> > >>> multiplication [scalar and vector]. Could you give me
> > >>> a reference to such module?
> > >> 
> > >> NumPy
> > >> 
> > >> Or one of these libraries (ctypes or Cython):
> > >> 
> > >> BLAS (Intel MKL, ACML, ACML-GPU, GotoBLAS2, or ATLAS)
> > >> Intel VML
> > >> ACML-VM
> > > 
> > > Thanks for that.  Last time I looked at numpy (for
> > > Python3) it was available in source only.  I know, real
> > > men do compile, but I am an old man...  I will compile
> > > if it is unavoidable, but in case of numpy it does not
> > > seem  a simple matter. Am I badly mistaken?
> > 
> > On UNIX machines with compilers and headers properly
> > installed, it's really pretty straightforward.
> 
> Mostly (on ubuntu/debian) that means do this [Untested]
> $ aptitude build-dep python-numpy
> Then you should be ready to build/compile numpy from source

Thank you, Robert and Rusi,

I will try it RSN, but first the latest version of ubuntu that 
should become available this week (including today?!).

OldAl.
-- 
Algis
http://akabaila.pcug.org.au/StructuralAnalysis.pdf

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