There is one (huge and very badly scaled) problem
Just for curiosity. How big is this instance and why it is badly scaled?
where
glp_simplex(..) fails to find a feasible solution (even after two days
of computation ...).
Maybe it would be useful to introduce artificial variables in
finds correct
solution; if not, please report. Thanks.
Andrew Makhorin
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Forwarded Message
From: Robert Baier robert.ba...@uni-bayreuth.de
To: help-glpk@gnu.org
Cc: huijuan...@uni-bayreuth.de huijuan...@uni-bayreuth.de
Subject: request for a feature (maximal iteration number or callback
function in glpk_simplex)
Date: Thu, 16 May 2013 18:30:28 +0200
Forwarded Message
From: Philipp p_roech...@web.de
To: help-glpk@gnu.org
Subject: Invalid MEX-file
Date: Tue, 07 May 2013 15:43:18 +0200
Hallo,
i tried to use glpk with matlab but i have problem. I downloaded the
file here http://glpkmex.sourceforge.net/
and added the folder to
Are the forall and exists iterated expressions still supported? I see
in the documentation that both are of the form
iterated-operator indexing-expression integrand
but I can't seem to get either to work. Are these still supported by
glpk v 4.45?
Yes, these operators are
On Mon, 2013-04-29 at 18:48 -0500, Michael Hennebry wrote:
On Sat, 27 Apr 2013, Heinrich Schuchardt wrote:
the current definition of the MIP gap is compatible to other optimizers
like CPLEX.
To the best of of my knowledge,
the terminal output is designed to be read by humans.
It will
please, update the documentation to clearly point out that an error is
thrown in glp_find_col
and glp_find row if not preceded by a call to glp_create_index.
Okay, I will add a paragraph to clarify the issue.
Wouldn't it be a good idea to let these functions implicitly call
Perhaps I'm missing something, buy why expose glp_create_index at all?
By default the name index is not created. If the user wants to find rows
or columns by name (i.e. to determine their ordinal numbers in the
problem object), he should enable this feature with glp_create_index.
Note that
When I use primal simplex method to solve an unbounded LP problem.
Checking status gives this:
glp_get_status() returns GLP_UNBND,
glp_get_prim_stat() returns GLP_FEAS,
glp_get_dual_stat() returns GLP_NOFEAS.
Then using dual simplex method to solve the same problem, I
I attach a picture of a 100% gap on integer programming on GLPK.
Some minutes later, the gap even increased to 200%.
Is it normal?
If you need, I can send you the model.
Yes, this can happen if the best integer feasible solution (incumbent
value) and the best solution to lp
Robbie,
There is a typo in the formula for computing mip gap on the page
http://en.wikibooks.org/wiki/GLPK/Terminal_output
The denominator should be |best_mip| + eps.
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Forwarded Message
From: Dieter Kömle dieter.koe...@gmx.net
To: help-glpk@gnu.org
Subject: Ipopt GMPL Interface
Date: Sun, 21 Apr 2013 20:12:46 +0200
Hello everyone!
I am new to GLPK and so far I'm very impressed by it's capabilities. My
question goes to solving non-linear
The University of Pisa Computer Science Department
have also reimplemented the original RELAX-IV
Fortran code, but into C++ instead. They offer
their version with warning that the algorithm may
fail to converge. The full text is:
RelaxIV is our C++ re-implementation of the
Relaxation
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
GLPK 4.49 Release Information
*
Release date: April 16, 2013
GLPK (GNU Linear Programming Kit) is intended for solving large-scale
linear programming (LP), mixed integer linear programming (MIP), and
other related
This is great news. I have found many uses of minimum cost
network-flow over the years, including revenue management models,
small models for doing first-come, first serve and last-come,
first-serve connections within the transportation industry, passenger
rail crew rostering problems, and a
This may only mean that optimal solution to the root lp relaxation
is
integer feasible, and therefore the mip has been solved.
Well, I thought that it wasn't true, in fact the manual says:
The difference between optimal solution to LP relaxation and
corresponding MIP solution is
On Mon, 2013-04-08 at 18:45 +0200, Giorgio Sartor wrote:
I have a model to which I can provide a initial feasible solution.
How can I do that?
The GLPK reference manual offers two different methods: one is by
using the routine glp_read_mip and the second is by using the callback
routine
Unfortunately, the general case is that it will not work.
The reason is that there is skew among the various Linux distros
particularly relative to libc with the result that executables tend to
dump core if run on a different distro. This is the reason that
commercial software running on
Forwarded Message
From: Sina Burkhardt sina.burkha...@gmx.de
To: 'Andrew Makhorin' m...@gnu.org
Subject: AW: [Fwd: Re: [Help-glpk] [Fwd: How to rewrite a nonlinear
expression in a linear one]]
Date: Tue, 2 Apr 2013 10:51:13 +0200
Hi Jeff,
thanks for your answer.
You're right
Forwarded Message
From: Sina Burkhardt sina.burkha...@gmx.de
To: help-glpk@gnu.org
Subject: How to rewrite a nonlinear expression in a linear one
Date: Mon, 1 Apr 2013 23:31:16 +0200
Hi all,
I’m currently writing my Master thesis and I hope someone can help me to
solve the
On Tue, 2013-03-26 at 08:18 -0700, un_zero_2011 wrote:
Hello,
When I a give glp_prob pointer to my function that call GLPK routines like
glp_add_rows(...) , I get the following message :
Invalid GLPK environment
Aborted (core dumped)
This error means that glpk internal memory areas
Forwarded Message
From: Hernandez Hormazabal, Jorge j.e.hernan...@liverpool.ac.uk
To: 'Jeffrey Kantor' kanto...@nd.edu, Hernandez Hormazabal, Jorge
j.e.hernan...@liverpool.ac.uk
Cc: help-glpk@gnu.org help-glpk@gnu.org
Subject: RE: [Help-glpk] GUSEK question - MRP
Date: Mon, 25
Nevertheless, now I have another error in the line 45. I have checked
all the brackets and everything, and I’m not sure why is the error:
“20130325_MRP_vJEH2.mod:45: syntax error in objective statement”
You forgot a semicolon.
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Forwarded Message
From: Vina Shukla vina.shu...@itcube.net
To: help-glpk@gnu.org
Cc: 'Vina Shukla' vina.shu...@itcube.net
Subject: GLPK - Vehicle routing problem with time window(VRPTW)
Date: Wed, 20 Mar 2013 15:13:54 +0530
Hello!
I'm just starting with GLPK (GNU Linear
On Tue, 2013-03-19 at 00:45 +0200, Figen Güngör wrote:
Can you please look at my question at Stackoverflow?
http://stackoverflow.com/questions/15488041/syntax-error-in-linear-programming-modelling-with-glpk?noredirect=1#comment21925482_15488041
var po := sum{i in I} c[i]*x[i];
var cost :=
The following project may be interesting for you:
http://code.google.com/p/cspsol/
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Forwarded Message
From: pmcnam paulm...@gmail.com
To: Help-glpk@gnu.org
Subject: Re: [Help-glpk] Any users of dwsolver (Dantzig-Wolfe)?
Date: Sat, 9 Mar 2013 07:50:18 -0800 (PST)
Hey Joey,
I'm interested in using your software though Matlab for a power systems
problem. I was
Forwarded Message
From: Guest276 caroline.niem...@tuhh.de
To: Help-glpk@gnu.org
Subject: [Help-glpk] No mod or round function available for variables
Date: Wed, 6 Mar 2013 07:05:05 -0800 (PST)
Hi,
I am trying to solve the following problem:
I have an LP with a max objective
] ...
minimize obj: delay;
in which case the new objective will have a zero shift, and the problem
will disappear.
FYI: Your glpk version is very old. The most recent version is 4.48.
Andrew Makhorin
Thanks
SV
--- On Sat, 3/2/13, Andrew Makhorin m...@gnu.org wrote:
From: Andrew
On Fri, 2013-03-01 at 09:06 -0800, Sundaravalli Narayanaswami wrote:
Hi all,
I am working on a MILP model for a transportation problem, with 24
data sets. Some of the data sets are solved to integer optimality and
others return an integer undefined by GLPK solver.
To verify and evaluate
Forwarded Message
From: Alexandre Saidi alexandresaidiglan...@gmail.com
To: glpk help-glpk@gnu.org
Cc: Alexandre Saidi alexandre.sa...@ec-lyon.fr, Andrew Makhorin
m...@gnu.org
Subject: Help demand
Date: Mon, 11 Feb 2013 10:14:48 +0100
Dears,
I've been fighting some (few
Forwarded Message
From: FileCluster Support supp...@filecluster.com
Reply-to: FileCluster Support supp...@filecluster.com
To: help-glpk@gnu.org
Subject: GLPK 4.48 - Filecluster.com Listing Confirmation
Date: Fri, 8 Feb 2013 13:49:50 +0200
Dear Developer,
You have received this
solution and try again. (I say 'resembles' because the TSP has a
special structure with permits other ways to avoid loops, these other
ways don't work here).
Except when I tried it didn't work, because the reason GLP_IROWGEN is
called with the solution to the LP relaxation, at which
Forwarded Message
From: Softpedia Editorial Team softedi...@softpedia.com
To: help-glpk@gnu.org
Subject: GLPK included in the Softpedia software database
Date: Tue, 5 Feb 2013 18:05:01 -0500 (EST)
Hello,
As you may already know, GLPK, one of your products, is part of
and remove unwanted symbols from glpk.h in the next release.
In the next release I think to rename lpx_check_kkt (it is the only
routine from old api which is still used in new api) to glp_check_kkt
and then remove all lpx routines from the package.
Best regards,
Andrew Makhorin
As Jeffrey say:
Sometimes small changes in numerics can make a big difference in how
the branches of an MIP problem are explored
The FPU Control Word directly impact how glpk will explore branches.
It can be different by thread. The default value is not the same if you
are using visual
, because some api
routines were changed/removed. Or I did something wrong?
Andrew Makhorin
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GLPK 4.48 Release Information
*
Release date: January 28, 2013
GLPK (GNU Linear Programming Kit) is intended for solving large-scale
linear programming (LP), mixed integer linear programming (MIP), and
other related
This is a maintainer release.
Must read This is a maintenance release.
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I have been looking for around a month into glpk, mainly minimizing a
linear problem (no integer programming).
Some times, the problem is infeasible, and i started looking into
Chinneck iis algorithms.
As a start, I started by implementing a relaxation of a large
infeasible problem,
it with other
GLPK users interested in reenterable binaries.
Andrew Makhorin
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decomposition that I might be able to adapt to work in GLPK to
monitor the evolution of the solution.
Could you please explain what exactly do you need to do?
Andrew Makhorin
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Forwarded Message
From: Ali Raza rizvisa...@gmail.com
To: help-glpk@gnu.org
Subject: GNU Program
Date: Tue, 15 Jan 2013 17:44:24 -0500
I have a quick question. I am trying to write a simple program in GNU
software. I am having difficities and it is giving me errors. I have not
Forwarded Message
From: Matteo Fischetti DEI m.fische...@gmail.com
Reply-to: m.fische...@gmail.com
To: Andrew Makhorin m...@gnu.org
Subject: Re: [Help-glpk] Help: How to build MIP model
Date: Fri, 04 Jan 2013 15:43:34 +0100
Hi Andrew.
to easy writing a MIP model (in Cplex
Forwarded Message
From: Vladimir Dergachev volo...@caltech.edu
To: glpk xypron xypron.g...@gmx.de
Cc: Reginald Beardsley pulask...@yahoo.com, help-glpk@gnu.org
Subject: Re: [Help-glpk] Optimization and Multicore GLPK
Date: Tue, 25 Dec 2012 01:03:13 -0800 (PST)
On Tue, 25 Dec
On Tue, 2012-12-25 at 19:00 -0200, Hugo Mezarina wrote:
I am looking for someone willing to teach me how to model the Weighted
Tardiness Problem (as decrived at
http://people.brunel.ac.uk/~mastjjb/jeb/orlib/wtinfo.html) to solve it
with glpsol and receiving the input given there.
For modeling
-20050101272
Best regards,
Andrew Makhorin
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As a native english speaker let me deny, on all our behalf,
resposibility for users of internet slang. see
http://www.internetslang.com/W_2F-meaning-definition.asp
IAWTC
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Does anybody have tried to solve a Sudoko instance with a BigM method
(to say all of the digits of a line must be different).
Using integer variables (like 0 = x[i,j] = 9) to model sudoku
solutions together with all different constraints leads to a poor
formulation which is hard to solve with
Forwarded Message
From: Matteo Fischetti DEI m.fische...@gmail.com
Reply-to: m.fische...@gmail.com
To: Andrew Makhorin m...@gnu.org
Subject: randomization in MIPs
Date: Mon, 17 Dec 2012 11:28:11 +0100
Hi Andrew.
I have a paper on the role of randomization at
http
So, depending on the random seeds, your instance can be solved in 79 or
1816 sec.s (!!)
Looks like a black magic.
I encountered this when developed a mip preprocessing. At some moment it
was absolutely unclear to me to which form the original instance should
be transformed.
mips the solution
time grows exponentially, this approach helps not so much (until you
have 2**n processors, where n is the number of integer variables :). It
seems to me that algorithmic solutions are able to provide much greater
performance.
Andrew Makhorin
Dear Prof. Fischetti,
Thank you very much for your information.
Andrew Makhorin
On Thu, 2012-12-13 at 17:34 +0100, Matteo Fischetti DEI wrote:
Dear friends,
I posted at
http://www.dei.unipd.it/~fisch/proximity_search.pdf
a joint work with Michele Monaci with an outline of our
] = 0 and pres[0] = { 1, 101, 102 }, j *cannot* be
assigned 2, and therefore Stand_Type[314,2,17] *cannot* be referenced
on computing this sum.
Andrew
On 08/12/2012 5:56 AM, Andrew Makhorin wrote:
Thanks for your response.
I entered the debugging statement you suggested; the triplet
Forwarded Message
From: Jean-Pierre Flori jpfl...@gmail.com
To: help-glpk@gnu.org
Subject: Build glpk as a shared library on Cygwin, MinGW and similar
systems
Date: Mon, 10 Dec 2012 19:20:19 +0100
Dear all,
First thanks for this great library.
I'd like to be able to build glpk
atzeri marco.atz...@gmail.com:
On 12/10/2012 8:20 PM, Andrew Makhorin wrote:
Forwarded Message
From: Jean-Pierre Flori jpfl...@gmail.com
To: help-glpk@gnu.org
Subject: Build glpk as a shared library on Cygwin, MinGW and similar
systems
Date: Mon, 10 Dec 2012 19:20:19 +0100
what to make of it.
I tried to reproduce the effect (see below). As you can see,
Stand_Type[314,2,17] is *not* referenced; otherwise, this would cause a
zero divide error. Please check your model and data more carefully;
maybe that parameter member is referenced somewhere else.
Andrew Makhorin
Forwarded Message
From: dante Baldeon Molleda reydan1...@hotmail.com
To: help-glpk@gnu.org
Subject: Greetings from Peru
Date: Sat, 8 Dec 2012 15:45:18 +
Hello good morning:
My monbre is Dante Baldeon belong in the National Engineering
University, specializing in pure
This is a question about how GLPK/GMPL handles parameters populated
with csv table data when executing statements.
I have a parameter Stand_Type (dimension 3), and a set of sets
pres{0..1}:
pres[0] = 1,101,102
pres[1]= 1,2,3,4,5,6
Stand_Type is indexed by { i in stands, j in pres[
Forwarded Message
From: Martin Lester les...@maths.ox.ac.uk
Reply-to: martin.les...@cs.ox.ac.uk
To: help-glpk@gnu.org
Subject: Using a SAT solver other than MiniSAT
Date: Wed, 5 Dec 2012 23:32:18 + (GMT)
Hi.
I have a problem (an encoding of the social golfers problem)
Forwarded Message
From: purser yura...@mail.ru
To: Help-glpk@gnu.org
Subject: [Help-glpk] Existing constraint
Date: Sun, 25 Nov 2012 23:58:14 -0800 (PST)
Hi, All!
When constraints declared, it is meaning, that each constraint must be
ensure. Is it possible to specify how at
That looks confusing? The maximize in the model
statement should be picked up, surely?? In which case
the --max should be unnecessary (except to override
a minimize in the code, from the command line).
The mps format does not allow specifying the objective sense.
Or am I
Forwarded Message
From: paterijk pater...@gmail.com
To: Help-glpk@gnu.org
Subject: [Help-glpk] Constraints on 2 successive elements of a set
Date: Tue, 20 Nov 2012 09:40:00 -0800 (PST)
Hi,
I'm trying to model a constraint using the GMPL modeling language.
To start, we have a
this work for you?
set J;
var x{i in J};
s.t. c{i in K : i card(J)} x[i] = x[i+1]
-Original Message-
From: help-glpk-bounces+marc.meketon=oliverwyman@gnu.org
[mailto:help-glpk-bounces+marc.meketon=oliverwyman@gnu.org] On Behalf
Of Andrew Makhorin
Sent
Looks like your instance is maximization while mps always assumes
minimization. You need either to change the objective sign in the
mathprog model or specify --max option for glpsol.
I don't understand this statement. Where do you specify -max option
for glpsol?
e.g. glpsol --math
maximize Discounted_Net_Value:
sum {s in STAND, p in PERIOD} Stand_Cut_Candidates[s,p] *
NPV_Calc[s,p] * FStand[s,p];
When you pass mps to glpsol, the optimization direction
is minimization by default, so you need to specify the
--max option to tell glpsol to maximize rather
It seems that --with-zlib missing or ommitted in GLPK-4.47. It is
present in GLPK-4.45 (I have not checked GLPK-4.4.46). I have checked
the configure.ac of 4.47. It was not there.
Any reason why it is ommitted / missing?
Now zlib is included in the glpk distribution.
Here's the part
The main bottleneck for GLPK MIP solver is GLPK LP solver, which is
still slow compared to CLP, for instance.
Success in solving mips mainly depends on cutting planes used, not on an
underlying lp solver.
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It seems that the generated FreeMPS and MPS could not be solved as
well in GLPK/Mathrog CLI (i.e. glpsol).
However, nothing wrong with GLPK/MathProg generated FreeMPS and MPS
MIP models. I check the other MIP models in example (e.g. bpp.mod)
glpsol --math bpp.mod --wfreemps bpp_fmps.mps
Actually, my constraint matrix can't be fit in the memory of my
machine. So, I assume that in cutting plane method, we don't need to
retain all the constraints in memory, So, can you please tell me more
about the restriction you mentioned?
You don't need to use the callback until you solve
Forwarded Message
From: alreva avazifedo...@yahoo.com
To: Help-glpk@gnu.org
Subject: [Help-glpk] adding constraints incrementally
Date: Fri, 9 Nov 2012 00:57:10 -0800 (PST)
Dear all,
I have a LP problem with a huge number of constraints which are saved into a
large file. The
Forwarded Message
From: Steven G steven123...@gmail.com
To: help-glpk@gnu.org
Subject: Converting AMPL Bender's Decomposition code to GLPK
Date: Thu, 8 Nov 2012 00:45:51 -0500
Hello,
I am trying to convert the following .data .mod and .run files from APML
to GLPK. The reason
If a row is non-active, changing its bounds does not affect the basic
solution.
This is only true for small change but not true for large change.
No, this is true for any change, assuming that a new lower bound remains
not greater than and a new upper bound remains not less than the current
Forwarded Message
From: Naurattan Makhija nmakh...@umich.edu
To: help-glpk@gnu.org
Subject: .run file equivalent in GLPK?
Date: Sat, 3 Nov 2012 18:42:19 -0400
Hello,
I need to know if there is a .run file in GLPK such as in AMPL, or a
similar file that would work the same as a
Forwarded Message
From: Minh Hoang minh.ho...@npl.co.uk
To: m...@gnu.org
Cc: help-glpk@gnu.org
Subject: Re: [Help-glpk] sensitivity analysis table in glpk [NC]
Date: Fri, 2 Nov 2012 15:19:19 -
Classification: NPL Management Ltd - Commercial
Hi Andrew,
The information in
The information in sensitivity analysis table in glpk seems to be
incorrect.
For example: for the problem in sample.c file and in the manual
section 1.3.1 (page 14).
[...]
However the correct range of the row r would be 200- +inf not (120-
520).
Do I miss something here?
The
For detailed explanations of the report structure please see Section 3.4
Post-optimal analysis routines in the glpk reference manual,
pp.107-114.
You need reading the paragraph Sensitivity analysis of objective
coefficients at basic variables on pp.112-113.
Heh. Using 'glpsol --minisat' gave the answer almost
instantaneously [it took ~15 hours without the --minisat option].
Please note that --minisat allows to find only an integer feasible
solution, i.e. it solves an integer feasibility problem. To find a
better integer feasible solution you
Hi Xypron,
in GLPK you are refer to an author Driebeck. In
https://www.xypron.de/webdav/Heinrich/Literature/Linear_Programming/Branching/Driebeck_1966_MSc.pdf
I find the author to be Norman J. Driebeek.
@Article{RePEc:inm:ormnsc:v:12:y:1966:i:7:p:576-587,
author={Norman J. Driebeek},
MIP optimzers are not fast solvers for constraint programming
problems.
That's a shame.
What would you suggest for solving a 10x10x10 binary array subject to
~200 restrictions?
It's not suitable for DLX.
Also, I suspect that any insights I have into my problems will not
improve on
Forwarded Message
From: robin hankin hankin.ro...@gmail.com
To: bug-g...@gnu.org
Subject: read.me
Date: Fri, 26 Oct 2012 22:26:28 +1300
Hello. glpk is awesome; keep it up!
There is no read.me file in the examples section, and I wasted quite
a long time fiddling about
Forwarded Message
From: ze...@gmx.de
To: help-glpk@gnu.org
Subject: Read Excel data into subscripted set
Date: Fri, 26 Oct 2012 14:46:44 +0200
Hi,
I have troubles with reading a 2-dimensional table in MS Excel and
putting the data into a subscripted set. In a first step, I try
I have a problem in mixed integer linear proramming
The problem has variable named g , u and parameter named b
u is binary variabel, g integer and b is parameter
g will have value 0, if u=0
and g=b if u=1
How can i write this problem?
Please see
I'm having difficulties on understanding the error message related to
reading data file.
hub-location_10.dat:112: 10 items missing in data group beginning
with _u
Didn't I use the correct number of parameters and set?
Your syntax is incorrect. Please see an example on page 51 of
It is well known, and your links show how, to use Newton's algorithm
(aka Newton Raphson's algorithm) to find the IRR, since it's really
find a root of a polynomial (see the other post by Jeffery Kantor,
which also describes the fact that depending on the cash flows, there
could be multiple
Erwin manage to implement IRR using GAMS (below).
http://yetanothermathprogrammingconsultant.blogspot.com.au/2010/03/calculating-irr-internal-rate-of-return.html
Any GAMS expert in the list who might be able to help translate this
GAMS IRR script into MathProg IRR script.
Literal
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To: help-glpk@gnu.org
Subject:
Date: Thu, 13 Sep 2012 11:01:43 +0800
Hi, I don't know how to represent this formula:
both p and KS are varibles, how to use multiplication for tow vars
s.t. psiM{i in I, j in J, k in K}:
Forwarded Message
From: Eric Anjie Guo ag...@cornell.edu
To: help-glpk@gnu.org
Subject: Trouble Linking with GLPK
Date: Wed, 12 Sep 2012 10:30:46 -0400
Hi All,
Sorry for the spam. I'm learning how to use GLPK, but seem to have
trouble linking with the library.
I compiled
Forwarded Message
From: Ankit Gandhi ankit.gandhiu...@students.iiit.ac.in
To: help-glpk@gnu.org
Subject: Specify initialization for MIP
Date: Mon, 10 Sep 2012 02:10:56 +0530
Hi,
I have been trying to solve MIP which contains around 1 integer
variables. Well, problem is very
i already solve a problem with glpk, but i want to validate it with
calculate the objective function in excel
but i have the different value between objective function in glpk and
excel.
glpk's objective function was 1805582104 , but if i calculate it with
excel it was 1838084829
hereby i
I've got this type of model working using MathProg
and glpsol, but now I'm trying to figure out how to
translate it to the strict form required by the C
API. Has anyone done this? What's the best way to
go about it? I'm going to need high performance on
some large problems.
For
there are differences in the
details.
Thank you very much for your information and for making the AMPL book
freely available.
Andrew Makhorin
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From: Sascha Anke sascha.a...@gmail.com
To: help-glpk@gnu.org
Subject: Implementation problems
Date: Thu, 30 Aug 2012 03:30:13 +0200
Hi,
I am trying to implement a model that is only given to me in a
conceptual form in GUSEK using GLPK.
When I try to solve
Forwarded Message
From: Robert Schroeder h2o...@gmail.com
To: help-glpk@gnu.org
Subject: MathProg model processing error: field CPT missing in input
table
Date: Tue, 28 Aug 2012 02:06:59 -0500
Hi,
I'm having trouble reading data from an input table. Funny thing is I
get the
I'm having trouble reading data from an input table. Funny thing is I
get the same basic error no matter if I use a CSV file or an Access
table (via ODBC). I'm very new to GLPK and the modelling language, so
perhaps I'm missing a key point, but I'm able to fill other Sets and
Parameters
I installed GLPK as a package in UBUNTU.
I did exactly how is wrutten in
http://en.wikibooks.org/wiki/GLPK/Linux_packages
When I tried to compile my file in C which calls the api routines I got a
message that glpk.h:29:20: fatal error: glpios.h: No such file or
directory.
Looks like gcc
Forwarded Message
From: Aly Megahed a...@gatech.edu
To: Robbie Morrison rob...@actrix.co.nz, glpk xypron
xypron.g...@gmx.de
Cc: GLPK help help-glpk@gnu.org
Subject: Re: [Help-glpk] [Fwd: No Memory Available Error]
Date: Sat, 18 Aug 2012 08:31:16 -0400 (EDT)
Thanks a lot for your
An interesting article on the simplex algorithm.
Journalistic, but written by a mathematician from the
University of Leeds, UK.
Elwes, Richard. 2012. The algorithm that runs the
world. New Scientist v215 no2877 p32-37.
doi:10.1016/S0262-4079(12)62078-8
web :
Forwarded Message
From: Aly Megahed a...@gatech.edu
To: glpk xypron xypron.g...@gmx.de
Cc: help-glpk@gnu.org
Subject: No Memory Available Error
Date: Wed, 15 Aug 2012 09:58:24 -0400 (EDT)
Hi guys,
I have two questions:
I am trying to solve a model that I generate its data
I follow your suggestions and I considered the following situation:
var check_t1 {(m,k) in FERMI, (j,p,m) in V_TECNOLOGICI } binary;
param BigP := max {(j,p) in FERMI} fine_fermo[j,p];
s.t. k2 {(m,k) in FERMI, (j,p,m) in V_TECNOLOGICI}:
inizio_fermo[m,k] = start[j,p,m] + BigP *
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