Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.python > #53468

Re: Simplex Algorithm

Path csiph.com!usenet.pasdenom.info!aioe.org!news.stack.nl!newsfeed.xs4all.nl!newsfeed2.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Return-Path <python-python-list@m.gmane.org>
X-Original-To python-list@python.org
Delivered-To python-list@mail.python.org
X-Spam-Status OK 0.004
X-Spam-Evidence '*H*': 0.99; '*S*': 0.00; 'url:pypi': 0.03; 'algorithm': 0.04; 'conventions': 0.07; 'conventions.': 0.09; 'linear': 0.09; 'positioned': 0.09; 'received:80.91': 0.09; 'received:80.91.229': 0.09; 'received:gmane.org': 0.09; 'received:list': 0.09; 'python': 0.11; "wouldn't": 0.14; 'kern': 0.16; 'programmatic': 0.16; 'received:80.91.229.3': 0.16; 'received:plane.gmane.org': 0.16; 'solver': 0.16; 'solver,': 0.16; 'tommy': 0.16; 'underlying': 0.16; 'language': 0.16; 'wrote:': 0.18; 'properly': 0.19; 'solution.': 0.20; 'work,': 0.20; 'programming': 0.22; 'header:User-Agent:1': 0.23; 'interpret': 0.24; "i've": 0.25; 'compiled': 0.26; 'excel': 0.26; 'header:X -Complaints-To:1': 0.27; 'header:In-Reply-To:1': 0.27; 'tried': 0.27; 'robert': 0.30; "i'm": 0.30; '(which': 0.31; 'getting': 0.31; 'anyone': 0.31; 'class': 0.32; 'figure': 0.32; 'url:python': 0.33; 'sources': 0.33; "can't": 0.35; 'something': 0.35; 'convert': 0.35; 'test': 0.35; 'but': 0.35; 'there': 0.35; 'url:org': 0.36; 'too': 0.37; 'represent': 0.38; 'to:addr:python- list': 0.38; 'rather': 0.38; 'itself': 0.39; 'to:addr:python.org': 0.39; 'received:org': 0.40; 'how': 0.40; 'easy': 0.60; 'show': 0.63; 'choose': 0.64; 'our': 0.64; 'different': 0.65; 'spot': 0.65; 'world': 0.66; 'between': 0.67; 'believe': 0.68; 'results': 0.69; 'eco': 0.84; 'forced': 0.84; 'terrible': 0.84; 'vba': 0.84; 'luck': 0.93; 'modelling': 0.93
X-Injected-Via-Gmane http://gmane.org/
To python-list@python.org
From Robert Kern <robert.kern@gmail.com>
Subject Re: Simplex Algorithm
Date Mon, 02 Sep 2013 10:55:43 +0100
References <1PRUt.242963$ZD2.40442@fx19.iad>
Mime-Version 1.0
Content-Type text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding 7bit
X-Gmane-NNTP-Posting-Host 213.1.240.226
User-Agent Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:17.0) Gecko/20130801 Thunderbird/17.0.8
In-Reply-To <1PRUt.242963$ZD2.40442@fx19.iad>
X-BeenThere python-list@python.org
X-Mailman-Version 2.1.15
Precedence list
List-Id General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe <http://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive <http://mail.python.org/pipermail/python-list/>
List-Post <mailto:python-list@python.org>
List-Help <mailto:python-list-request@python.org?subject=help>
List-Subscribe <http://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups comp.lang.python
Message-ID <mailman.477.1378115748.19984.python-list@python.org> (permalink)
Lines 37
NNTP-Posting-Host 2001:888:2000:d::a6
X-Trace 1378115748 news.xs4all.nl 15893 [2001:888:2000:d::a6]:58114
X-Complaints-To abuse@xs4all.nl
Xref csiph.com comp.lang.python:53468

Show key headers only | View raw


On 2013-09-02 02:26, Tommy Vee wrote:
> Anyone know where I can get an easy to use Python class or algorithm for the
> Simplex optimization algorithm?  I've tried the one in the link below, but I
> can't figure out if a) I'm using it properly, or b) where to get the solution.
> BTW, I tried some test scenarios using MS Excel's "Solver" and just can't get
> this algorithm to match Excel's results (which is spot on).
>
> http://taw9.hubpages.com/hub/Simplex-Algorithm-in-Python
>
> BTW, if I can't something to work, I'm going to be forced to use the VBA
> programmatic Excel interface. That wouldn't be too bad, but the data comes from
> a DB and getting it properly positioned to use Excel's "Solver" is very
> painful.  A Python approach would be much cleaner.

Can you show some of the test scenarios that you tried? There are different 
conventions in how to represent a linear programming problem, and different 
solvers may choose different conventions. You may have to convert between 
representations.

You may have better luck with the PuLP interface:

   https://pypi.python.org/pypi/PuLP

PuLP itself is just a modelling language rather than a solver, but the sources 
do contain compiled binaries for the CoinMP solver so it will work out-of-box on 
popular platforms, like Windows.

   https://projects.coin-or.org/CoinMP

-- 
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

Back to comp.lang.python | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

Simplex Algorithm Tommy Vee <xxxxx@xxxxxx.xxx> - 2013-09-01 21:26 -0400
  Re: Simplex Algorithm Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-09-02 09:06 +0100
    Re: Simplex Algorithm Tommy Vee <xxxxx@xxxxxx.xxx> - 2013-09-02 10:42 -0400
    Re: Simplex Algorithm Tommy Vee <vitaletom1@gmail.com> - 2013-09-02 10:42 -0400
  Re: Simplex Algorithm Robert Kern <robert.kern@gmail.com> - 2013-09-02 10:45 +0100
  Re: Simplex Algorithm Robert Kern <robert.kern@gmail.com> - 2013-09-02 10:55 +0100
    Re: Simplex Algorithm Tommy Vee <xxxxx@xxxxxx.xxx> - 2013-09-02 11:06 -0400
      Re: Simplex Algorithm Robert Kern <robert.kern@gmail.com> - 2013-09-02 16:43 +0100
        Re: Simplex Algorithm Tommy Vee <xxxxx@xxxxxx.xxx> - 2013-09-02 14:59 -0400
        Re: Simplex Algorithm Tommy Vee <vitaletom1@gmail.com> - 2013-09-02 14:59 -0400
    Re: Simplex Algorithm Tommy Vee <vitaletom1@gmail.com> - 2013-09-02 11:06 -0400
  Re: Simplex Algorithm Tony the Tiger <tony@tiger.invalid> - 2013-09-16 13:47 -0500

csiph-web