Re: [Help-glpk] Suggestions to solve the master problem faster in a Branch-and-Price model.

> > When I have to remove a basic variable, I fix its bound using the > GLP_FX constant as Heinrich suggested, and when I have to remove a > non-basic constraint, I unbind it using GLP_FR, before removing them > from the problem object in a further iteration where the variable is > no more basic

Re: [Help-glpk] Access the LP relaxation solution in lp_intopt

> Is there some way to access the LP Relaxation solution that is found > before integer optimization begins in glp_intopt() function? > Specify --nomip option for glpsol, in which case integrality constraints are ignored. Using the option -o filename or -w filename you may write the solution to

[Help-glpk] [Fwd: RE: Fwd: glpk terminating abnormally]]

longer have that error. We will be working towards implementing the new version of GLPK in our next version. Marc -Original Message- From: Andrew Makhorin [mailto:m...@gnu.org] Sent: March-21-14 5:04 PM To: marc.thom...@statcan.gc.ca Cc: xypron.g...@gmx.de; help-glpk@gnu.org Subject: RE

[Help-glpk] glpk 4.54 release information

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 GLPK 4.54 Release Information * Release date: March 28, 2014 GLPK (GNU Linear Programming Kit) is intended for solving large-scale linear programming (LP), mixed integer linear programming (MIP), and other related problems

[Help-glpk] [Fwd: tutorial]

Forwarded Message From: Khoa Vo To: help-glpk@gnu.org Subject: tutorial Date: Mon, 31 Mar 2014 14:19:51 +0700 hi I'm want to use this to solve some optimization problem, but I dont know how to input and compute it (Im using matlab). Optimization is not my major so can you send m

[Help-glpk] [Fwd: need help about gusek]

Forwarded Message From: 郑志鹏 <304758...@qq.com> To: Makhorin Subject: need help about gusek Date: Thu, 3 Apr 2014 17:38:17 +0800 Hello,Andrew: My name is Zheng Zhipeng,I am a student from China,these days I am using the GUSEk program. There are some problems I don't know

Re: [Help-glpk] [Fwd: need help about gusek]

> Second ,if I want to solve the least-absolute-deviation problem using > gusek,how should I convert the objective function.My objective function > is following: > > sum{a in A,c in C}|(sum{i in I,j in J} > pl[i,j,a,c]*d[i,j]-col[a,c])| > > +sum{a in A,b in B,c in C}|(sum{i in

Re: [Help-glpk] About glp_set_col_bnds()

> My name is Nan Hu. Now I’m using GLPK for a LP problem and facing a > potential bug. > > My code is like > > glp_simplex(ilp, NULL); > double tmp = glp_get_col_prim(ilp, index); > while(tmp != 0) { > glp_set_col_bnds(ilp, index, GLP_FX, 0.0, 0.0); > glp_simplex(ilp, NULL); > tm

[Help-glpk] [Fwd: MathProg to Cplex problem]

Forwarded Message From: smor...@ibisc.univ-evry.fr To: help-glpk@gnu.org Subject: MathProg to Cplex problem Date: Mon, 7 Apr 2014 11:24:10 +0200 Hi All, I'm a new user of both Cplex and Glpsol, and i'm currently facing a strange problem which you guys might know how to go throug

Re: [Help-glpk] [Fwd: MathProg to Cplex problem]

> I'm a new user of both Cplex and Glpsol, and i'm currently facing a > strange problem which you guys might know how to go through. I want to > convert a MathProg file into cplex formulation so that i can solve it > faster. > > I use the simple command : glpsol -m model.mod -d data.dat --check >

Re: [Help-glpk] Calculate sqrt of var

On Tue, 2014-04-08 at 18:46 +0100, Tiago Costa wrote: > Hi, > > I'm trying to apply the following restriction: > > subject to calc2 {m in M} : > fee[m] = sqrt(1000 + (100 + (sum {n in N} (n mod 47))) * (sum {l in > L} prod[l,m])); > > However since prod[l,m] is a var, I get "argument for s

Re: [Help-glpk] Objective too large

On Tue, 2014-04-08 at 14:06 -0400, Edward Seaman wrote: > To Whom It May Concern, > I am generating an AMPL file with a very large objective. I have > attached the file for your information/reference. > > > What I have found from testing is that if I reduce the objective to > below 7652 terms- th

Re: [Help-glpk] API (4.54 glpk.h) vs. Docs

> I would like to clear up some things about the API as described in > glpk.h (for version 4.54) versus what I can find in the (excellent) > documentation: > > * In 'glp_iocp', the parameters 'use_sol' (GLP_ON/GLP_OFF?), 'save_sol', > and 'alien' are listed, but I have not found a description i

Re: [Help-glpk] Simple glpk program giving me wrong maximum value output?

On Tue, 2014-04-15 at 09:21 +0530, Amit Gurung wrote: > "I do not know why the maximum value is 0 when it should have been -5. > Not just this example, but with any other negative value, the output > is always zero. How can I fix this?" You incorrectly set lower bounds for 2nd and 4th rows (see be

Re: [Help-glpk] Objective too large

On Wed, 2014-04-16 at 16:37 -0400, Edward Seaman wrote: > Andrew, > I tried 4.54 and the Gusek 0-2-17. They both fail in the same way. > > > Regards, > Ed > The exception code reported by MS Windows is 0xC0FD that means the stack overflow exception. Thus, to avoid the error glpsol needs to

Re: [Help-glpk] 4.54 sgf_reduce_nuc triggers assertion on line 165 of sgf.c

ctorize, as follows: . . . 1300 int i, j, k, k1, k2, p, q, nnz; singl = 0; /* disable singleton phase */ 1301 /* build matrix V = A in row-wise format */ 1302 luf_build_v_rows(luf, rs_prev); . . . I will fix this bug in a next release. Andrew Makhorin ___

Re: [Help-glpk] Calculate sqrt of var

Nigel, > The following model estimates the sqrt of a variable. If you think it > will > enhance glpk's examples, then please add it. Thank you very much. Could you please add more detailed comments into your model? Andrew Makhorin ___

Re: [Help-glpk] GLPK GNU LINEAR PROGRAMMING KIT - ECCN - Export Control Classification Number

> Could you please inform the ECCN – Export Control Classification > Number for the software GLPK GNU LINEAR PROGRAMMING KIT? > Glpk is publicly available software and free of charge to download, so it is covered by TSU/TSPA and does not require a ECCN. __

Re: [Help-glpk] Solving linear/nonlinear systems of equations via glpk

> In an academic paper it is claimed finding all solutions to non linear > systems of equations by using glpk.There, dual simplex method is said > to use. > My question is how we can define this problem in glpk to have the > solutions. > In other words how can we define a problem about solving sys

Re: [Help-glpk] glp_transform_row/col: len' <= len or other means of selecting ind/val array lengths?

> When using glp_transform_row/col, is there a guarantee that len' <= len No, len' can be greater than len. > or is there another means of selecting an appropriate length to use for > allocating memory for the arrays ind and val? Glp_transform_row guarantees that 0 <= len' <= n, where n is the

[Help-glpk] [Fwd: Is it possible to enumerate all integer points?]

Forwarded Message From: Sebastian Gutsche To: help-glpk@gnu.org Subject: Is it possible to enumerate all integer points? Date: Tue, 13 May 2014 10:30:59 +0200 Dear all, is it possible to enumerate all feasible points of a ILP Ax>=b? Thank you, Sebastian ___

[Help-glpk] [Fwd: Question about GLPK]

Forwarded Message From: Pierre Jean GALIAZZO To: help-glpk@gnu.org Subject: Question about GLPK Date: Thu, 15 May 2014 11:59:05 +0200 Hello, I’m a dataminer consultant and I’m testing GLPK for one of our client. I would know if it’s possible to use a combination of a “s

[Help-glpk] [Fwd: Valid input range for glp_mem_limit]

Forwarded Message From: Bradford Boyle To: help-glpk@gnu.org Subject: Valid input range for glp_mem_limit Date: Fri, 16 May 2014 22:15:54 -0400 I'm updating some old code that links against glpk and in the process, I came across an interesting change in the behavior of `glp_mem_

[Help-glpk] [Fwd: Re: Problem using Rglpk with Ruby]

Forwarded Message From: Eric Winter To: help-glpk@gnu.org Subject: Re: [Help-glpk] Problem using Rglpk with Ruby Date: Wed, 11 Jun 2014 13:13:27 -0400 Lukas, Your issue probably stems from a lack of good examples. rglpk (as opposed to Rglpk) comes with a single example. That e

[Help-glpk] [Fwd: jar files and libglpk.so]

Forwarded Message From: João Campos To: help-glpk@gnu.org Subject: jar files and libglpk.so Date: Thu, 12 Jun 2014 11:05:31 + Dear Sir, I am trying to use GLPK with java in eclipse. I have installed GLPK for Java in my computer, but it has been hard for me to use it in ecl

Re: [Help-glpk] glp_ios_add_row: name argument usable afterwards

> I would be grateful if somebody could tell me whether the name argument > that can be passed in the search tree glp_ios_add_row function can be > used afterwards for some purpose, e.g., to access that row as with the > problem function glp_find_row. > Yes, you can use the name passed to glp_

[Help-glpk] [Fwd: Help required : glp_alloc: no memory avaialable]

Forwarded Message From: Prem Chedella To: help-glpk@gnu.org Subject: Help required : glp_alloc: no memory avaialable Date: Wed, 18 Jun 2014 10:55:44 + Hi All, I’m using GPLK library 4.54 in Window environment for one of the project. For smaller set the of data, it

Re: [Help-glpk] GLPK Documentation in Spanish...

Dear Pablo, Thank you very much for your contribution to glpk. I will include your translation (both tex and pdf) in a next release of the package. Currently the tex and pdf files can be downloaded from: http://sourceforge.net/projects/noumenon/files/ With best wishes, Andrew Makhorin On

[Help-glpk] glpk 4.55 release information

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 GLPK 4.55 Release Information * Release date: August 22, 2014 GLPK (GNU Linear Programming Kit) is intended for solving large-scale linear programming (LP), mixed integer linear programming (MIP), and other related problem

Re: [Help-glpk] GLPSOL issue

> I am having an issue using the standalone glpsol solver: on some > particular instances, the solver enters a never-ending elaboration (I > let it run for 8 hours, when 20 seconds would be already a huge time > for an instance of that size), without finding any solution. Try using --cuts option

[Help-glpk] [Fwd: Syntax error]

Forwarded Message From: Przemek Przybyszewski To: help-glpk@gnu.org Subject: Syntax error Date: Thu, 11 Sep 2014 17:19:53 +0200 Hi, do you know what does such a message mean? "character l' not allowed". I have found your e-mail address in http://stackoverflow.com/questions

[Help-glpk] [Fwd: Higher resolution glp_time under POSIX]

Forwarded Message From: C Blake Reply-to: C Blake To: help-glpk@gnu.org Subject: Higher resolution glp_time under POSIX Date: Wed, 1 Oct 2014 07:41:17 -0400 Hey. About 55% of the test programs in examples/*.mod run in under a single millisecond on my test machine. It is hard

[Help-glpk] [Fwd: Table Simplex: inverse of the matrix of the basic variables]

Forwarded Message From: Mateus Pereira Martin To: help-glpk@gnu.org Subject: Table Simplex: inverse of the matrix of the basic variables Date: Tue, 14 Oct 2014 12:53:46 -0300 Hi All, I wonder how can I get (using API functions) the inverse of the basic matrix variables (B^-1)

Re: [Help-glpk] Table Simplex: inverse of the matrix of the basic variables

> I wonder how can I get (using API functions) the inverse of the basic > matrix variables (B^-1) after obtaining the optimum of a linear > problem. The api routine glp_ftran computes y = inv(B) * x for a given vector x, so if you specify x = ej, where ej is j-th unity vector (i.e. j-th column of

[Help-glpk] [Fwd: problem glpk_4_55_java.dll for win32]

Forwarded Message From: frédéric quesnel To: help-glpk@gnu.org Subject: problem glpk_4_55_java.dll for win32 Date: Fri, 31 Oct 2014 11:07:55 -0400 Hi, I am trying to use glpk in a java application. I want to create a runnable jar file that can be used on another computer. So

Re: [Help-glpk] [Fwd: Build glpk as a shared library on Cygwin, MinGW and similar systems]

> So I suggest to integrate the patch with the next release. Please provide me with a patched configure.ac (maybe post it to the list?). I don't have cygwin64 and cannot test the script by myself. Is the patched script applicable on both cygwin32 and cygwin64?

[Help-glpk] Fwd: Re: MIP Help

On Fri, 2014-11-14 at 09:06 +0100, Erik Quaeghebeur wrote: > Dear Sam, > > > > I am new to GLPK and I can't the MIP solver to report integer values. > > Basically, when I first call the simplex, and then cal glp_inop, the > > message report that it found a solution but when I call glp_mip_col_val

Re: [Help-glpk] subscribe

Please send administrative requests (like subscribe, unsubscribe, etc.) to help-glpk-requ...@gnu.org . Another way to subscribe is to use the mailing list interface; see http://mail.gnu.org/mailman/listinfo/help-glpk . ___ Help-glpk mailing list Help-

Re: [Help-glpk] API problem

> I attached 2 files. One is .lp file and second sample.c > > > Both are trying to solve same problem. With glpsol i have no problem > to solve it, but when I try to modify sample.c so it solve the same > problem it just write back: > GLPK Simplex Optimizer, v4.55 > 26 rows, 9 columns, 90 non-ze

Re: [Help-glpk] Column Generation

and generic cutting planes, i.e. nearly all the features provided by the ios. Andrew Makhorin ___ Help-glpk mailing list Help-glpk@gnu.org https://lists.gnu.org/mailman/listinfo/help-glpk

Re: [Help-glpk] Making GLPK silent

> Any way this can be turned off as well? glpk.h doesn't seem to expose > anything more either. > glp_term_out(GLP_OFF); ___ Help-glpk mailing list Help-glpk@gnu.org https://lists.gnu.org/mailman/listinfo/help-glpk

Re: [Help-glpk] Calculation of Time Used in Solution Parameters

> I have run an integer linear programming written in GNU MathProg using > GLPSOL. It has shown in parameters of solution that > > > Time Used: 0.2 secs > > > However, real time that program consumes to find the solution is much > longer than Time Used. > What is difference in calculation of

[Help-glpk] [Fwd: Binary variables act like float]

Forwarded Message From: Laguna Loire To: help-glpk@gnu.org Subject: Binary variables act like float Date: Thu, 26 Feb 2015 01:31:40 +0100 Dear GLPK developers, I'm a student from Roma Tre University and I'm working on a project using your glpk-java library. I'm having trouble

Re: [Help-glpk] sensitivity analysis

> I have some misunderstand about GLPK's sensitivity analysis. I read > several times the GLPK documentation but some details no more clear > for me. > Let investigate the following problem: > max > 9x1+20x2+45x3 > subject to > 2x1+5x2+15x3<=5000 > 4x1+6x2+8x3<=2 > end > I get the following ou

[Help-glpk] [Fwd: GLPK enhancement]

Forwarded Message From: Robert Rand Reply-to: Robert Rand To: help-glpk@gnu.org Subject: GLPK enhancement Date: Mon, 16 Mar 2015 17:34:49 + (UTC) Hello, I am presently working with GLPK, and would find it very useful to have a function which reads data from a string. S

Re: [Help-glpk] [Fwd: GLPK enhancement]

_read_data; or ii) using glpk api. Best regards, Andrew Makhorin ___ Help-glpk mailing list Help-glpk@gnu.org https://lists.gnu.org/mailman/listinfo/help-glpk

Re: [Help-glpk] [Fwd: GLPK enhancement]

> >> I am presently working with GLPK, and would find it very useful to have > >> a function which reads data from a string. > > > > Probably such a feature would be useful, however, it seems quite exotic. > > Actually, such functionality would be very useful for anyone using GLPK > in an interac

Re: [Help-glpk] sensitivity analysis

> I read again the documentation. The Chapter 4 helped me a lot. But I > still do not understand the sensitivity analysis exactly. > Let see again the the problem: > > max > 9x1+20x2+45x3 > subject to > c1:2x1+5x2+15x3<=5000 > c2:4x1+6x2+8x3<=2 > end > > For the second constraint I get an

Re: [Help-glpk] sensitivity analysis

> unlimitedly increase, value of c2 would be 1 (which is its upper > bound). Must read "which is its an implied upper bound due to other constraints". ___ Help-glpk mailing list Help-glpk@gnu.org https://lists.gnu.org/mailman/listinfo/help-glpk

Re: [Help-glpk] Bilinear problem

> Is it possible to solve a problem with bilinear constraints using > GLPK? > No, because bilinear constraints are non-linear while glpk allows only linear ones. ___ Help-glpk mailing list Help-glpk@gnu.org https://lists.gnu.org/mailman/listinfo/hel

Re: [Help-glpk] MILP and CP

impossible to automatically choose a preferable way for a particular model, so I decided not to implement such a feature. Andrew Makhorin ___ Help-glpk mailing list Help-glpk@gnu.org https://lists.gnu.org/mailman/listinfo/help-glpk

[Help-glpk] [Fwd: A query and a request for help]

Forwarded Message From: sanaullah swati To: m...@gnu.org Subject: A query and a request for help Date: Thu, 9 Apr 2015 22:27:26 +0500 Dear sir, sir i have this objective function for creating districts by clustering of census data (gis data) Inline image 1 The above objectiv

Re: [Help-glpk] glp_mip_col_val is returning negative zero

On Fri, 2015-05-01 at 15:17 +, Agostina Kodelia wrote: > Hi! > I'm solving a very simple postman travelling problem with > the glp_intopt method. When I retrieved the column value > with glp_mip_col_val, it returns a negative zero. The zero is alright, > but I don't understand why has a minus,

[Help-glpk] [Fwd: a question]

Forwarded Message From: sgholiza To: help-glpk@gnu.org Subject: a question Date: Mon, 13 Jul 2015 16:48:55 +0200 Dear GLPK, First of all I would like to thank you for your attention.. Actually, I would like to use an optimization Java library to solve my optimization model. Wh

[Help-glpk] [Fwd: GLPK exception]

Forwarded Message From: Roberto Trunfio To: m...@gnu.org Cc: m...@mai2.rcnet.ru Subject: GLPK exception Date: Mon, 13 Jul 2015 22:40:04 +0200 Dear Mantainer, This is Roberto, from Berlin. I work as software engineer for Zalando SE. I like to experiment open source library sinc

[Help-glpk] [Fwd: GLPK Dll function question]

Forwarded Message From: 조성국 Reply-to: sunggoog@samsung.com To: help-glpk@gnu.org, bug-g...@gnu.org Subject: GLPK Dll function question Date: Wed, 15 Jul 2015 09:30:34 + (GMT) Hello. I use the win32 version glpk_4_55.dll and I am developing the C# Windows program.

[Help-glpk] [Fwd: GLPK solution format]

Forwarded Message From: Atzeni, Simone To: help-glpk@gnu.org Subject: GLPK solution format Date: Thu, 23 Jul 2015 15:14:35 + Hi, I am running GLPK on a fairly big problem. It finds the solution and the number are big. I noticed that if I use the option –o they are “appro

Re: [Help-glpk] GLPK solution format

> I am running GLPK on a fairly big problem. > It finds the solution and the number are big. > I noticed that if I use the option –o they are “approximated” in the > format: 4.99e+08 > In particular two values of my solution, for the variables i498 and > i499, are: > > > 998 i498 *

Re: [Help-glpk] GLPK got out-of-memory exception when solving linear programming models

> > I am trying yto build a linear programming model by C# VS 2013 from > Optimization.Framework. > > The LP has 5000 constraints and 6000 decision variables. > How many non-zero constraint coefficients in your model? > > I got out-of-memory exceptin when I tried to solve it by GLPK. > >

Re: [Help-glpk] Zero valued coefficients

> currently > > glp_set_mat_col() > glp_set_mat_row() > glp_load_matrix() > > may be used to place zero valued coefficients in the sparse matrix > stored as structure GLPAIJ. > > These zero values are not needed in any way by GLPK. > > It is left to the calling problem to avoid passing zeros.

Re: [Help-glpk] Trying to Install GLPK through Cygwin

> > I did the ./configure and make and make check. I think something is > wrong. Below you can see the messages. > > ltdl.h is a standard header, so probably your cygwin installation is incomplete. You may try "./configure --disable-shared". You also may try to download precompiled glpk binar

[Help-glpk] [Fwd: About reading the relative mip gap from the glp_prob C struct]

Forwarded Message From: Nathann Cohen To: GLPK help , David Coudert Subject: About reading the relative mip gap from the glp_prob C struct Date: Wed, 26 Aug 2015 20:12:26 +0200 Hello everybody, David Coudert and I are contributors to a software called Sagemath [1], and we curr

[Help-glpk] [Fwd: Modifying the model after reading from a lp file]

Forwarded Message From: Yaser Tohidi To: help-glpk@gnu.org Subject: Modifying the model after reading from a lp file Date: Tue, 1 Sep 2015 17:05:50 +0200 Hi I wonder how it is possible to modify a model after reading from a lp file (by glp_read_lp). I have a loop inside which

Re: [Help-glpk] glp_find_col

On Thu, 2015-09-03 at 16:36 +0200, Yaser Tohidi wrote: > I cannot use "glp_find_col". It retrieves zero always even I use the > following code. I also create index at the beginning by > glp_create-index. > > > const char *name; > name= glp_get_col_name(lp1,j); > i=glp_find_col(lp1,name); > > >

[Help-glpk] [Fwd: How to install GLPK. Windows 7 64 bits.]

Forwarded Message From: EMANUEL DEGNI JUNIOR To: help-glpk@gnu.org Subject: How to install GLPK. Windows 7 64 bits. Date: Thu, 3 Sep 2015 19:30:10 -0300 Hello! Please send a step by step procedure to install GNU GLPK in my notebook, running Windows 7 64 bit and to route Window

Re: [Help-glpk] glp_find_col

_find_col returns zero. > I hope it's clear now. > > On Thu, Sep 3, 2015 at 8:53 PM, Andrew Makhorin wrote: > On Thu, 2015-09-03 at 16:36 +0200, Yaser Tohidi wrote: > > I cannot use "glp_find_col". It retrieves zero always even I > use the

[Help-glpk] [Fwd: A Request]

Forwarded Message From: Shaghayegh Mokarami To: help-glpk@gnu.org Subject: A Request Date: Sat, 5 Sep 2015 18:55:19 +0430 Hi I'm not very familar to GLPK. My problem contains two LP model, LP1 and LP2 which be solved separately. The variables of model LP1 and LP2 are defined

Re: [Help-glpk] what is the maximum LP model size that can be built/solved in GLPK

Please see: http://lists.gnu.org/archive/html/help-glpk/2008-07/msg00044.html Note that your model may happen to be hard for glpk due to its size. On Sun, 2015-09-13 at 23:02 -0400, usa usa wrote: > Hi, > > > I am new to GPLK. > > > Is it possible to use GLPK to build/solve an Linear Porgr

Re: [Help-glpk] build glpk.dll for C# so that I can call it from VS2013 on win7.

> I would like to build it by Visual C#. > See http://en.wikibooks.org/wiki/GLPK/C-Sharp . ___ Help-glpk mailing list Help-glpk@gnu.org https://lists.gnu.org/mailman/listinfo/help-glpk

Re: [Help-glpk] MIP presolver and dual simplex in root relaxation

+++>>> smcp.meth = GLP_DUALP; 382 mip->it_cnt = P->it_cnt; 383 ret = glp_simplex(mip, &smcp); PS: If possible, please post to me (not to the list) your gzipped model (in any format supported by glpsol). Thanks. Andrew Makhorin ___

Re: [Help-glpk] exact solutions

> When I use the option --exact and --xcheck I get unfortunately > a vertex with fractional coordinates expressed as 1.67 instead > of the expected 5/3.I know I can compute the exact solution > since I have a basis of incident inequalities. But it is a little bit > sad > to have to recompu

Re: [Help-glpk] MIP presolver and dual simplex in root relaxation

> Here is a mathprog-file that behaves as I described. Thank you. I was able to reproduce the behavior. JFYI: Numerical instability in the primal simplex happens because the choice of a pivot on some steps leads to a badly conditioned basis and as a result to non-accurate intermediate solutions.

[Help-glpk] [Fwd: glpk tuning]

Forwarded Message From: Karol Rydzewski To: help-glpk@gnu.org Subject: glpk tuning Date: Mon, 21 Sep 2015 23:37:03 +0200 Hi, I would like to make use of glpk library in my C programme. I have made some tests of it in Octave and it works great, giving an expected results. Howeve

Re: [Help-glpk] [Fwd: glpk tuning]

> I would like to make use of glpk library in my C programme. I have made > some tests of it in Octave and it works great, giving an expected > results. However using "raw" glpk via C gives different, wrong, results. Looks like you forgot to specify column (i.e. variable) bounds. On api level all

Re: [Help-glpk] Quadratic Programming

> I wonder if it’s possible to solve an optimisation problem with linear > constraints and quadratic objective function (the problem is convex) > by glpk. > No, glpk does not support solving non-linear problems. ___ Help-glpk mailing list Help-glpk@

[Help-glpk] glpk 4.56 release information

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 GLPK 4.56 Release Information * Release date: October 1, 2015 GLPK (GNU Linear Programming Kit) is intended for solving large-scale linear programming (LP), mixed integer linear programming (MIP), and other related problem

[Help-glpk] reincarnation of tspsol

introduced in glpk 3.2.1 (August 2002), however, later in glpk 4.20 (July 2007) it was removed because of significant changes in api. Now TSPSOL is again available and will be included in a next release of the package. Any comments are appreciated. Andrew Makhorin tsp.tar.gz Description

Re: [Help-glpk] reincarnation of tspsol

onal. > > tspsol throws an error if EOF is missing. > > http://comopt.ifi.uni-heidelberg.de/software/TSPLIB95/DOC.PS > says: > COMMENTS: Additional comments ... > > Please, observe the plural form. tspsol throws a error when reaching a > second comment where it should not.

Re: [Help-glpk] [Fwd: tutorial]

your examples in a subdirectory, add README, then gzip the subdir and post it to me. I will include that subdir in my codebase into glpk/examples. Thanks. Andrew Makhorin ___ Help-glpk mailing list Help-glpk@gnu.org https://lists.gnu.org/mailman/listinfo/help-glpk

Re: [Help-glpk] reincarnation of tspsol

> Probably n should be limited, say, by 1000. Tspsol doesn't use column > generation, so the problem object includes *all* (n**2/2-n) Must read ((n**2)-n)/2. > binary > variables; e.g. for n = 1000 it is about 500,000 variables. > I think n = 500 is a practical limit for tspsol. Below here is

[Help-glpk] some tspsol benchmarks

Solver: TSPSOL for GLPK 4.56 Computer: Intel Celeron J1800 2.41 GHz OS: Debian GNU/Linux 8.1.0 "Jessie" Compiler: GCC 4.7.2 (options used: -O2) Test set: TSPLIB 95 Instance N Solution Lower BoundNodes It

Re: [Help-glpk] reincarnation of tspsol

tspsol throws a error when reaching a > second comment where it should not. > Fixed. > In README you describe that the TSPSOL95 format is supported. > I could not find the keyword 'NODE_COORD_TYPE' in the coding. > This feature is only needed to display the route, so not

Re: [Help-glpk] reincarnation of tspsol

> it for any other reason. > Probably the fact of specifying the callback routine can be used as a flag to disable primal heuristics, because the callback routine itself is able to apply heuristics performing necessary feasibility checks. Andrew Makhorin _

Re: [Help-glpk] reincarnation of tspsol

ay, row_gen) that explicitly allows row generation. By default it is clear (no row generation is allowed), and being set it disables all primal heuristics. Andrew Makhorin ___ Help-glpk mailing list Help-glpk@gnu.org https://lists.gnu.org/mailman/listinfo/help-glpk

Re: [Help-glpk] reincarnation of tspsol

> Why would you forbid all primal heuristics, e.g. the feasibility pump, to be > used in conjunction with row generation? > The result of the feasibility pump could be valid in which case the callback > would not add any lazy constraint. > As I understand you suggest to apply primal heuristics

Re: [Help-glpk] Double bounded vs. fixed

> Note the code that's commented out at the bottom. The code as it is as > shown says the overall linear system is infeasible (in the reals). > The row causing the infeasibility generated by the code above when Lower > == 0. > So the code is generating a double bounded row with ub = lb = 0. > U

Re: [Help-glpk] reincarnation of tspsol

> Therefore I still think that the option to disable the rounding > heuristic (as well as every other heuristic) should be available. > I've added sr_heur option to glp_iocp struct, which is GLP_ON by default. Probably it is the only option which should be explicitly disabled when row generatio

Re: [Help-glpk] Build using GLPK, solve using CLP and post solve using GLP

On Wed, 2015-10-28 at 17:31 +0100, Louis Mathieu wrote: > Hello, > > > I am currently using GLPK tu build my .mps matrix, solve it and use > post solving printf to get solution. > > > I would like to use CLP to solve my .mps. > > > What would be the easiest way to do so ? > > > I read that

Re: [Help-glpk] Build using GLPK, solve using CLP and post solve using GLP

> You may use the following sequence: > > glpsol -m foo.mod --check --wmps foo.mps > ...solve foo.mps and write solution to foo.sol... > glpsol -m foo.mod -r foo.sol > > For .sol format see the glpk manual (routines glp_read_sol for LP and > glp_read_mip for MIP). > Another way is to replace

[Help-glpk] [Fwd: GLPK packet]

Forwarded Message From: Fernando Garcia To: help-glpk@gnu.org Subject: GLPK packet Date: Thu, 29 Oct 2015 09:48:34 +0100 Good morning, My name is Fernando Garcia. First at all, congratulations for the development of this solver. I have one doubt with the use of the packet "g

Re: [Help-glpk] Using GLPK on windows 8

> Can I solve an LP model by GLPK on windows 8.1? > > > Could you please explain me (step by step) how to install GLPK on > windows 8 > > and also how to run a .mod file? > > > (Do I need additional program on my machine? (I install Visual Studio > 10, before.) > Please see http://en.wikib

Re: [Help-glpk] Build using GLPK, solve using CLP and post solve using GLP

On Mon, 2015-11-02 at 10:49 +0100, Louis Mathieu wrote: > Thanks for your answer > > > I also tried writing in freemps or lp. It makes the solution file much > easier to understand ! > > > One last question, do you know how are GLPK performances to build > matrix ? I did not find any benchmark

[Help-glpk] [Fwd: Adding constraints.]

Forwarded Message From: Fernando Garcia To: help-glpk@gnu.org Subject: Adding constraints. Date: Tue, 3 Nov 2015 14:07:23 +0100 Good evening, First at all, congratulations for the development of this solver. Here is my problem: I am trying to solve a Benders Decomposition pr

Re: [Help-glpk] expressing a constraint depending on a boolean variable

> Please could you help me to express the following constraint if > possible. > > > for i in {1..2} if V[i] =1 then 2<= sum {x in MySet} V2[x] <=3 > else (V[i] =0) then sum {x in MySet} V2[x] may > have any value (i do not care about the value in this case) > > > > > wit

Re: [Help-glpk] Using GLPK on windows 8

> I followed the instruction as you told, > But I still don't know how to execute " .mod" file using Visual > Studio, the glpk.h was included. > > (I want to apply glpk for my " .mod" files from my Mac in Window ) > If you has successfully built glpk, there must be glpsol.exe in subdirectory

Re: [Help-glpk] Using GLPK on windows 8

On Wed, 2015-11-04 at 16:07 +0300, Andrew Makhorin wrote: > > I followed the instruction as you told, > > But I still don't know how to execute " .mod" file using Visual > > Studio, the glpk.h was included. > > > > (I want to apply glpk for my "

Re: [Help-glpk] How I do for write a restriction with binary variables, with dynamic restriction

> I have a model which has the next lines > > set J:={1..3}; #Número de centrales hidroeléctricas del sistema > set T:={1..3}; #Número de periodos del horizonte temporal > > param Pmin{j in J, t in T}; > param Pmax{j in J, t in T}; > var v{j in J, t in T}, binary, >=0; > #constraint: > prodTer{j

Re: [Help-glpk] [PATCH] determine whether we are handling an error

On Thu, 2015-11-05 at 22:57 +0100, Jeroen Demeyer wrote: > On 2015-11-05 22:20, Heinrich Schuchardt wrote: > > Hello Jeroen, > > > > could you, please, describe the use case for the patch. > > My use case is really for using GLPK through SageMath, which is a > mathematical program with an interac

Re: [Help-glpk] [PATCH] determine whether we are handling an error

> Currently both normal messages and error messages are sent to stdout, > which does not match usual usage of output streams. The C standard does not require that. In my opinion, normal (usual) terminal-based applications should not use stderr at all; only system error messages (like segmentation

[Help-glpk] glpk 4.57 release information

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 GLPK 4.57 Release Information * Release date: November 08, 2015 GLPK (GNU Linear Programming Kit) is intended for solving large-scale linear programming (LP), mixed integer linear programming (MIP), and other related probl

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