any Python equivalent of Math::Polynomia l::Solve?

[Just]

While googling for a non-linear equation solver, I found
Math::Polynomia l::Solve in CPAN. It seems a great little module, except
it's not Python... I'm especially looking for its poly_root()
functionality (which solves arbitrary polynomials). Does anyone know of
a Python module/package that implements that?

Just

[Nick Coghlan]

Just wrote:

While googling for a non-linear equation solver, I found
Math::Polynomia l::Solve in CPAN. It seems a great little module, except
it's not Python... I'm especially looking for its poly_root()
functionality (which solves arbitrary polynomials). Does anyone know of
a Python module/package that implements that?

Just

Does SciPy do what you want? Specifically Scientific.Func tions.FindRoot [1] &
Scientific.Func tions.Polynomia l [2]

Regards,
Nick.

[1]
http://starship.python.net/~hinsen/S...entific_9.html
[2]
http://starship.python.net/~hinsen/S...ntific_13.html
--
Nick Coghlan | nc******@email. com | Brisbane, Australia
---------------------------------------------------------------
http://boredomandlaziness.skystorm.net

[Just]

In article <ma************ *************** ************@py thon.org>,
Nick Coghlan <nc******@iinet .net.au> wrote:

Just wrote:

While googling for a non-linear equation solver, I found
Math::Polynomia l::Solve in CPAN. It seems a great little module, except
it's not Python... I'm especially looking for its poly_root()
functionality (which solves arbitrary polynomials). Does anyone know of
a Python module/package that implements that?

Just

Does SciPy do what you want? Specifically Scientific.Func tions.FindRoot [1] &
Scientific.Func tions.Polynomia l [2]

Regards,
Nick.

[1]
http://starship.python.net/~hinsen/S...thonManual/Sci
entific_9.html
[2]
http://starship.python.net/~hinsen/S...thonManual/Sci
entific_13.html

(Hm, I had the impression that scipy != Konrad Hinsen's Scientific
module.)

I had played with [1], but it "only" calculates one root, and I need all
roots (specifically, for a quintic equation). [2] doesn't seem to be a
solver?

Just

[Terry Reedy]

"Just" <ju**@xs4all.nl > wrote in message
news:ju******** *************** *@news1.news.xs 4all.nl...

Does SciPy do what you want? Specifically Scientific.Func tions.FindRoot
[1] &
Scientific.Func tions.Polynomia l [2]
http://starship.python.net/~hinsen/S...thonManual/Sci
entific_9.html
[2]
http://starship.python.net/~hinsen/S...thonManual/Sci
entific_13.html

(Hm, I had the impression that scipy != Konrad Hinsen's Scientific
module.)

www.scipy.org (first hit on "Python SciPy" google search)

Terry J. Reedy

[John M. Gamble]

In article <ju************ ************@ne ws1.news.xs4all .nl>,
Just <ju**@xs4all.nl > wrote:

While googling for a non-linear equation solver, I found
Math::Polynomi al::Solve in CPAN. It seems a great little module, except
Thank you.
it's not Python...
Sorry about that.
I'm especially looking for its poly_root()
functionalit y (which solves arbitrary polynomials). Does anyone know of
a Python module/package that implements that?

Are you looking for that particular algorithm, or for any
source that will find the roots of the polynomial? The
original source for the algorithm used in the module is
from Hiroshi Murakami's Fortran source, and it shouldn't
be too difficult to repeat the translation process to python.

--
-john

February 28 1997: Last day libraries could order catalogue cards
from the Library of Congress.

[Just]

In article <cv**********@e 250.ripco.com>,
jg*****@ripco.c om (John M. Gamble) wrote:

In article <ju************ ************@ne ws1.news.xs4all .nl>,
Just <ju**@xs4all.nl > wrote:

While googling for a non-linear equation solver, I found
Math::Polynomi al::Solve in CPAN. It seems a great little module, except
Thank you.

it's not Python...

Sorry about that.

Heh, how big are the odds you find the author of an arbitrary Perl
module on c.l.py...

I'm especially looking for its poly_root()
functionalit y (which solves arbitrary polynomials). Does anyone know of
a Python module/package that implements that?

Are you looking for that particular algorithm, or for any
source that will find the roots of the polynomial?

Any will do. As I wrote in another post, I'm currently only looking for
a quintic equation solver, which your module does very nicely.
The
original source for the algorithm used in the module is
from Hiroshi Murakami's Fortran source, and it shouldn't
be too difficult to repeat the translation process to python.

Ah ok, I'll try to locate that (following the instruction in Solve.pm
didn't work for me :( ).

Just

[John M. Gamble]

In article <ju************ ************@ne ws1.news.xs4all .nl>,
Just <ju**@xs4all.nl > wrote:

Heh, how big are the odds you find the author of an arbitrary Perl
module on c.l.py...

Hey, that's why it's called lurking.

Any will do. As I wrote in another post, I'm currently only looking for
a quintic equation solver, which your module does very nicely.

The
original source for the algorithm used in the module is
from Hiroshi Murakami's Fortran source, and it shouldn't
be too difficult to repeat the translation process to python.

Ah ok, I'll try to locate that (following the instruction in Solve.pm
didn't work for me :( ).

Ouch. I just did a quick search and found that that site has undergone
a few changes, and the code that i reference is missing. A few other
links in the docs are stale too. I need to update the documentation.

Anyway, doing a search for 'hqr' and Eispack got me a lot of sites.
In particular, this one is pretty friendly:

<http://netlib.enseeiht .fr/eispack/>

Look at the source for balanc.f (does the prep-work) and hqr.f
(does the solving). Minor annoyance: the real and imaginary
parts of the roots are in separate arrays. I combined them into
complex types in my perl source, in case you want to make a
comparison.

Of course, all this may be moot if the other suggestions
work out.

--
-john

February 28 1997: Last day libraries could order catalogue cards
from the Library of Congress.

[Just]

In article <cv**********@e 250.ripco.com>,
jg*****@ripco.c om (John M. Gamble) wrote:

The
original source for the algorithm used in the module is
from Hiroshi Murakami's Fortran source, and it shouldn't
be too difficult to repeat the translation process to python.
Ah ok, I'll try to locate that (following the instruction in Solve.pm
didn't work for me :( ).

Ouch. I just did a quick search and found that that site has undergone
a few changes, and the code that i reference is missing. A few other
links in the docs are stale too. I need to update the documentation.

Anyway, doing a search for 'hqr' and Eispack got me a lot of sites.
In particular, this one is pretty friendly:

<http://netlib.enseeiht .fr/eispack/>

Look at the source for balanc.f (does the prep-work) and hqr.f
(does the solving). Minor annoyance: the real and imaginary
parts of the roots are in separate arrays. I combined them into
complex types in my perl source, in case you want to make a
comparison.

Thanks! I'll check that out.
Of course, all this may be moot if the other suggestions
work out.

SciPy indeed appear to contain a solver, but I'm currently stuck in
trying to _get_ it for my platform (OSX). I'm definitely not going to
install a Fortran compiler just to evaluate it (even though my name is
not "Ilias" ;-). Also, SciPy is _huge_, so maybe a Python translation of
that Fortran code or your Perl code will turn out to be more attractive
after all...

Just

[Raymond L. Buvel]

Just wrote:
<snip>

SciPy indeed appear to contain a solver, but I'm currently stuck in
trying to _get_ it for my platform (OSX). I'm definitely not going to
install a Fortran compiler just to evaluate it (even though my name is
not "Ilias" ;-). Also, SciPy is _huge_, so maybe a Python translation of
that Fortran code or your Perl code will turn out to be more attractive
after all...

Just

The GNU Scientific Library has a nice root finder for polynomials with
real coefficients. I have wrapped this with Pyrex to work with my
ratfun module see:

http://calcrpnpy.sourceforge.net/ratfun.html

If this will suit your needs, I can send you an alpha release of the
package with the root finder. It is not pure Python. I requires Pyrex
and a C compiler to install. My guess is that it will work on OSX as
well as it does on Linux. This functionality will be included in the
next release of the ratfun package but I still have to unit test a
number of components and update the documentation. Consequently, an
official release will not happen soon.

Ray

[Just]

In article <I6************ ***@twister.rdc-kc.rr.com>,
"Raymond L. Buvel" <le******@wi.rr .com> wrote:

Just wrote:
<snip>

SciPy indeed appear to contain a solver, but I'm currently stuck in
trying to _get_ it for my platform (OSX). I'm definitely not going to
install a Fortran compiler just to evaluate it (even though my name is
not "Ilias" ;-). Also, SciPy is _huge_, so maybe a Python translation of
that Fortran code or your Perl code will turn out to be more attractive
after all...

Just

The GNU Scientific Library has a nice root finder for polynomials with
real coefficients. I have wrapped this with Pyrex to work with my
ratfun module see:

http://calcrpnpy.sourceforge.net/ratfun.html

If this will suit your needs, I can send you an alpha release of the
package with the root finder. It is not pure Python. I requires Pyrex
and a C compiler to install. My guess is that it will work on OSX as
well as it does on Linux. This functionality will be included in the
next release of the ratfun package but I still have to unit test a
number of components and update the documentation. Consequently, an
official release will not happen soon.

Thank you, I'll check this out. I had come across GSL, but not Python
bindings. (GPL is probably a problem for my project, but it's very good
to know anyway.)

On the other hand, I just finished translating the relevant portions of
Math::Polynomia l::Solve to Python, so I'm probably all set, at least for
now. Thanks everyone for the responses, especially to John Gamble!

Just