### Re: [Bug-glpk] Infinite loop

becomes primal infeasible within a tolerance, that sometimes may lead to an infinite loop. This is a lack of implementation. I hope to finish soon a new, more robust and faster simplex code, which will be included in glpk as a basic lp solver. Andrew Makhorin

### Re: [Bug-glpk] bug

I am using the GLPK solver to resolve MIP problems. In the stand-alone program, there are options called cuts cover, --gomory to put cut strategies on the process of solve. In the refman.ps (manual) I found the integer control parameter LPX_K_USECUTS, but this parameter does not exist, and I

### Re: RES: [Bug-glpk] bug

Yes! I am using GLPK 4.11! The command to invoke this parameter that I am using is: lpx_set_int_parm(lp, LPX_K_USECUTS, 3); The third parameter must be LPX_C_COVER, LPX_C_CLIQUE, LPX_C_GOMORY, or LPX_C_ALL; bitwise or is allowed. ___

### Re: [Bug-glpk] time limit odd case

to be much less than the time to solve the entire problem. The time limit is just an estimation, so probably there is no need to trace it exactly. Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### [Bug-glpk] patch to fix the bug in glpk 4.12

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 To fix the '-lm' bug in glpk 4.12 just replace the original files 'configure.in' and 'configure' in the glpk distribution by the patched ones included in the attachment. Then configure and compile the package in usual way. -BEGIN PGP

### Re: [Bug-glpk] Variables defined more than once

Perhaps not a bug, but the following constatnts are defined twice to the same values in glplpx.h with annoying consequences when I try to bind to ruby. [EMAIL PROTECTED] ruby]$ ruby sample.rb ./nigelzGLPK.so: warning: already initialized constant LPX_FR ./nigelzGLPK.so: warning: already

### Re: [Bug-glpk] RUN GLPSOL ITANIUM

I NEED TO RUN GLPSOL IN MY ITANIUM PROCESSOR. I CAN DO ALLMOST EVERITHING, EXEPT RUN FROM .mod FILES, I GOT AN UNALIGMENT ERROR WHE I TRIED TO DO THAT. CAN YOU HELP ME TO SET UP GLPSOL IN MY ITANIUM Please provide more details. GLPK conforms to ILP32, LLP64, and LP64 programming models

### Re: [Bug-glpk] GLPK 4.15 fails to build on mac

GLPK 4.13 and 4.14 configured and built without an issue. Now with 4.15, I eventually get the following error: ld: common symbols not allowed with MH_DYLIB output format with the -multi_module option /usr/local/lib/libgmp.a(mp_bpl.o) definition of common ___gmp_junk (size 4)

### Re: [Bug-glpk] Possible Bug

Please, can you tell me if this is a bug in glpksol? This is not a bug. var p {i in Facility} integer = 1 = 10; /* level of production in 0..10 then * 10 = %s */ minimize time: sum {j in Resource} ( max(Resource_Objective[j] - Resource_Qte[j],0) / (sum{i in Facility} Facility_Data[i,

### Re: [Bug-glpk] lib_set_print_hook disappeared

Can you also add to the header file something that easily allows detecting the version of GLPK? Something like the following would be OK: /* The major number of the GLPK version. */ #define GLPK_VERSION_MAJOR 4 /* The minor number of the GLPK version. */ #define GLPK_VERSION_MINOR 15

### [Bug-glpk] Re: [Help-glpk] Error delete column

; } } } #endif return; } (I marked the fragment to be inserted by #if-#endif.) Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### Re: [Bug-glpk] Assertion failure in glp_simplex GLPK-4.18

); } return ret; } Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### Re: [Bug-glpk] write_freemps does not write objective function coefficients

Trying to debug a stack error in GLPK, I am writing the problem out at every iteration of a column generation scheme Initially only in the free mps format, but then also in the lp format One major and one minor error occur: major: write_freemps does not write the objective function

### Re: [Bug-glpk] detecting a memory leak in glpk 4.17

I am using GLPK 4.17 compiled for windows to a DLL The application solves a problem in a column generation scheme. The algorithm completes successfully. When shutting down the application, GLPK gives the following memory leak detecting memory leaks: Data 4.17 with size 136 bytes I assume

### [Bug-glpk] Re: error in mip presolver

and now I cant reproduce the error. If it crops up agian I will be more carefull in saving the mps file. Sorry for wasting your time here. Graham. On 7/19/07, Andrew Makhorin [EMAIL PROTECTED] wrote: The following free mps file generates the following error when I run intopt on it but now

### [Bug-glpk] Re: GLPSOL, Version 4.9 (Windows XP Service Pack 2 Installation) - Bug

provide more information about the bug? Please note that the most recent version of glpk is 4.20. GLPK distribution can be ftp'ed from ftp://ftp.gnu.org/gnu/glpk/ or from some mirror ftp sites; see http://www.gnu.org/order/ftp.html. Andrew Makhorin Reading model section from mod2.mod... Reading

### Re: [Bug-glpk] Bug in glpk 4.21?

, i); } /* determine original column bounds */ and then compile the package as usual. Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### Re: [Bug-glpk] Bug in glpk 4.21?

-mip_obj - mip-c0; 751: L[0] = mip-mip_obj - mip-c0, U[0] = +DBL_MAX; Please note that these changes will appear in the next version of the package. Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman

### [Bug-glpk] bug found in the routines glp_set_mat_row and glp_set_mat_col

the element from the row list */ 815 xassert(aij-r_prev == NULL); 816 aij-row-ptr = aij-r_next; +++ if (aij-r_next != NULL) aij-r_next-r_prev = NULL; 817 /* remove the element from the column list */ Andrew Makhorin ___ Bug

### Re: [Bug-glpk] Another Bug in mip presolver?

Some time ago I posted a bug report regarding a bug in the presolver. Somehow the attached model file vanished, so I assume it has been rejected due to its size. I tried to reproduce the error with a reduced model, but I didnt succeed on that, so I try again to send the original model file,

### Re: [Bug-glpk] Fwd: bug in GLPK 4.17

I'm sorry, I think I did'nt send you the correct files. The problem is with eq.lp. Alain Forwarded Message From: Alain Poirier [EMAIL PROTECTED] To: bug-glpk@gnu.org Subject: bug in GLPK 4.17 Date: Wed, 12 Sep 2007 13:00:36 -0400 Hello, Here's a problem which GLPK

### Re: [Bug-glpk] GLPK Model Transfer to CPLEX LP File

I found there is a bug in the GLPK when transfering MathProg model to CPLEX LP file. While CPLEX LP does not allow for slash / in the model, certain / in the MathProg model is not transfered to other symbol which causes CPLEX reporting error. Specifically, in my MathProg model, I have a set S

### Re: [Bug-glpk] Bug with LP format

I think I've come across a bug with the function 'lpx_write_cpxlp' for writing linear programs in CPLEX LP format. The problem is with upper bounded variables that do not have lower bound. Such a variable say x is written by GLPK as x = upper_bound in the Bounds section of the LP file.

### Re: [Bug-glpk] internal error: row-lb != row-ub

Im an Octave user. I have tried to implement the so called Earth Movers Distance, a difference measure for distributions. It is an optimization problem that maps to a transportation problem instance and can be solved by linear programming. My script has worked well for many cases, but

### Re: [Bug-glpk] mip gap 0 causes return code time limit exceeded

Thank you for your report. However, as return code from lpx_intopt I get LPX_E_TMLIM (time limit exceeded), which I do not really understand. It is probably caused by the ret = GLP_ETMLIM; in glpios03.c line 1346. There should be a specific return code in glp_intopt, however, since it could

### [Bug-glpk] incorrect version number in glpk.h

In glpk 4.24 the header glpk.h was not changed properly in order to reflect the new minor version number. To fix the bug please replace line 33 in file glpk.h: #define GLP_MINOR_VERSION 23 by the following one: #define GLP_MINOR_VERSION 24 This should be done before compiling and installing

### Re: [Bug-glpk] xassert fail in MIR cut back substitution

I have a MIP where an assertion in the new mir cut generation routines in GLPK 4.24 is failing. Find attached a cplex-lp file. I was able to produce the problem on a linux 64bit machine, and it also appear on some other platforms, but not on every, e.g., not on linux 32bit. It should pop up

### Re: [Bug-glpk] Bad return of a routine

Hi Andrew. I wish to inform you that when I compiled GLPK 4.25 under windows it said that routine sort_pool should return a value. Thank you for the bug report. Hope the compiler issues a warning, not error. Otherwise please replace the following line (file glpios03.c, line 1605): static

### Re: [Bug-glpk] internal error: x = ub; file glpios03.c, line 264

to numerical difficulties, because the underlying lp solver is not able to provide sufficient accuracy for such integer variables. Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### Re: [Bug-glpk] printf statement being ignored with large constraint

How am I to know there is a problem with my model? Shouldn't glpsol give me an error when it tries to generate the model? If the solver started to solve the model, it was generated successfully, without errors. What I do know is that if I comment out the third contraint

### Re: [Bug-glpk] printf statement being ignored with large constraint

Can't you have a look at my model (attached) and try running it through glpsol yourself? The line in question is line 13. I don't think it's a problem with the printf statement, as it works with line 13 commented out. There is no error. Introducing constraint

### Re: [Bug-glpk] Assertion failed: ipp != ipp; ..\src\glpipp02.c at line 801

Xypron, Thank you for your bug report. running glpsol --cuts on the following model gives an error Model has been successfully generated ipp_basic_tech: 5 row(s) and 0 column(s) removed Assertion failed: ipp != ipp Error detected in file ..\src\glpipp02.c at line 801 glpsol --version

### Re: [Bug-glpk] Re: minimization flag ignored by 'glp_simplex' (GLPK 4.25)

I am currently experiencing a problem getting 'minimization' to stick, even though I set this flag explicitly with 'glp_set_obj_dir' and 'glp_get_obj_dir' returns 'GLP_MIN' before and after the solver call. This is strange, because the direction flag is explicitly stored in the problem object

### Re: [Bug-glpk] Bus Error using GLPK on SGI-Altix when call lpx_read_model

I #39;m using GLPK (4.25) and I have a program that works very well in a x86 (IA-32) architecture. I started to port my program to a SGI-Altix (8 x Itanium IA-64) and when a call a lpx_read_model function a get a Bus Error. I know this error is caused by unaligned acess of memory

### Re: [Bug-glpk] static build workaround for 4.30

concern the shared library support used by some glpk modules. If you need to build the shared/static glpk library, you should pass options --enable-shared and/or --enable-static to the configure script. To see all available options, run 'configure --help'. Andrew Makhorin

### Re: [Bug-glpk] lpx_simplex and bad basis status

in the lpx_simplex method of GLPK 4.31 (and 4.30), a bad initial basis yields a return code LPX_E_FAULT, while I would expect to get an LPX_E_BADB. I think this just needs a little change at glplpx01.c:379. Lpx_simplex is obsolete and kept only for backward compatibility. Since it does not

### Re: [Bug-glpk] Segmentation fault in glpsql.c

the following model code creates a segmentation fault: table ta { l in LOCATIONS } OUT 'iODBC' 'DSN=glpk;UID=glpk;PWD=gnu' 'UPDATE result_t12 SET DATE = ' date ' WHERE ID = 4' 'UPDATE result_t12 SET QUAN = ? WHERE LOC = ? AND ID = 4' : quantity[l], l, 4 ~ id; The number of

### Re: [Bug-glpk] Segmentation fault (core dumped) in table statement

), because some dca-arg[k] is not initialized (contains 0x3f3f3f3f written by xmalloc/xcalloc). I need a time to fix the bug. Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### Re: [Bug-glpk] Segmentation fault (core dumped) in table statement

To fix the bug reported by Xypron please apply the patch below. Note that the bug will be fixed in the next release of the package. *** glpk-4.31/src/glpmpl03.cTue Sep 2 12:00:00 2008 --- glpk-4.32/src/glpmpl03.cThu Sep 4 12:00:00 2008 *** *** 4895,4900 --- 4895,4903

### Re: [Bug-glpk] Problem in the MIP problem

in particular, in the cplex lp file Yi0_copy should be specified as follows: Bounds Yi0_copy = 1 This is not necessary, because glp_read_lp correctly set the types of variables having identical lower and upper bounds to GLP_FX. ___ Bug-glpk

### Re: [Bug-glpk] Problem in the MIP problem

0 = Yi4_copy = 1 0 = Yi5_copy = 1 0 = Yi6_copy = 1 0 = Yi7_copy = 1 0 = Yi8_copy = 1 0 = Yi9_copy = 1 Generals Yi0_copy Yi1_copy Yi2_copy Yi3_copy Yi4_copy Yi5_copy Yi6_copy Yi7_copy Yi8_copy Yi9_copy End Andrew Makhorin wrote: in particular, in the cplex lp

### Re: [Bug-glpk] Problem in the MIP problem

I don't use functions glp_read_lp or glp_read_cpxlp. And, I use GLP_FX (not GLP_DB) to fix bounds for the first variable. So, I don't understand. And, when I use lpx_write_cpxlp, I obtain this result. The problem is that variables aren't integer and the first variable bound is displayed

### [Bug-glpk] Re: table compatibility of GLPK 4.32

I am working on GLPK 4.32 and ran in to the following error while trying to use the table command. Is there a known bug in the version that handles tables ? Many thanks || Sincerely || Rajesh -- [EMAIL

### Re: [Bug-glpk] glpk 4.32 on Mac OS X

I have run into a problem building octave 3.0.3 against glpk version 4.32. When I investigated the issue, I found that the build works correctly for version 4.31, but not 4.32. The offending symbols are For version 4.32: nm /usr/local/lib/libglpk.0.17.0.dylib | grep 'lib_[a-z]*_hook'

### Re: [Bug-glpk] Problem in the MIP problem

I check my code and I resolve my problem. But, an other problem appear. When I fix a variable at one, and after, I define the type as binary, then the lower bound is 0 instead of 1. I resolve this problem in declaring variables as integer. But, why glp_set_col_kind redefine the lower

### Re: [Bug-glpk] *** glibc detected *** /src/glpk-4.32/examples/.libs/lt-glpsol: double free or corruption (!prev)

/glpsql.c?view=diffr1=297r2=294diff_format=h Please gzip the new version of glpsql.c and post it to me via e-mail. Thanks. Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### Re: [Bug-glpk] Problem to solve MIP problem

I have this problem: When I use this routine (lpx_intopt(glpkProbPtr)), my problem is solved normally. But, when I use this routine (glp_intopt(glpkProbPtr,glpkParamMipPtr)), my problem doesn't solve the problem. The error message is: glp_intopt: optimal basis to initial LP relaxation

### Re: [Bug-glpk] link time errors for GLPK 4.33

Hi Robbie, I am having trouble linking against my new build of GLPK 4.33. This is somewhat puzzling as my build process is the same as always. First, my config options are: $ ./configure --disable-shared --with-gmp After installing, I get: $ glpsol --version GLPSOL: GLPK LP/MIP

### [Bug-glpk] bug detected in cplex-like interface to glpk (routine CPXdelsetrows)

A bug has been detected in the cplex-like interface to glpk api (routine CPXdelsetrows). To fix the bug right now please replace all files in subdirectory examples/cplex (glpk 4.33) by the patched files attached. cplex.tar.gz Description: GNU Zip compressed data

### Re: [Bug-glpk] 0 ** 0; result undefined

According to ISO/IEC 9899:TC2 (ISO C99) A domain error may occur if x is zero and y is zero. (in function pow). This standard also says (see subsection F.9.4.4, page 460): pow(x, 0) returns 1 for any x, even a NaN. However, this does not mean that the GNU MathProg must follow the same

### Re: [Bug-glpk] glpsol: crash on display

See, for example, the model examples/bpp.mod, where parameter z is defined recursively. ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### Re: [Bug-glpk] glpsol: crash on display

I see the point for indexed parameters (or sets) with bpp.mod. My solution is only valid for non indexed parameters and arrays. How about the following solution: When evaluating an element of a parameter GLPK earmarks it as being in evaluation. If the same element of the parameter is

### Re: [Bug-glpk] 0-ary slice not allowed

constraint s.t. cost {i in N, j in N} : t[i] - t[j] - sum{(i,j) in E} c[i,j] * x[i,j] = 0; leads to error 0-ary slice not allowed in glpmpl01.c, function expression_list. My expectation was that the sum is 0 if (i,j) is not an element of E and c[i,j] x[i,j] otherwise. This would be

### Re: [Bug-glpk] 0-ary slice not allowed

constraint s.t. cost {i in N, j in N} : t[i] - t[j] - sum{(i,j) in E} c[i,j] * x[i,j] = 0; leads to error 0-ary slice not allowed in glpmpl01.c, function expression_list. My expectation was that the sum is 0 if (i,j) is not an element of E and c[i,j] x[i,j] otherwise. This

### Re: [Bug-glpk] 0-ary slice not allowed

Just for clarity. Do you agree that the following notation is meaningless? sum{(2,3) in E} c[i,j] * x[i,j] The following model is correctly solved by GLPK: set E := {(2,3)}; var v{(i,j) in E}; s.t. con1 {(i,j) in E} : v[i,j] - sum{(2,k) in E : k == j} 1 = 0; var w{(i,j) in E}; s.t.

### [Bug-glpk] Re: C#; Error detected in file ..\src\glplib07.c at line 147

be you could tell me what is wrong? Thanks, Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### [Bug-glpk] Re: C#; Error detected in file ..\src\glplib07.c at line 147

I tried to run your example, t1.cs, with MS Visual Studio 2008, and encountered an error. Stripping the code off I detected that the error happens in the destructor. I found what causes the bug. Looks like a system call to DllMain due to the reason DLL_THREAD_DETACH or DLL_PROCESS_DETACH (in

### Re: [Bug-glpk] GLPSOL ends unexpectedly due to recursion

the model below leads to glpsol ending without result or error. I would have expected an error message like illegal recursion if the param statement cannot be resolved by the current implementation. (FYI: In error messages the GNU Coding Standards recommends to use the adjective invalid

### [Bug-glpk] Re: GLPK and Distributed Shared Memory System

not kill any threads of the distributed shared system. Could you provide more detailed information? Does the error happen within a glpk routine? If so, in which one? Thanks. Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http

### Re: [Bug-glpk] GLPK fails with MySQL ODBC Connector 5.1

when using GLPK with MySQL ODBC Connector 5.1 on 64bit Windows an error occurs. Please, apply the patch below to file src/glpsql.c Done. ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### [Bug-glpk] Re: [Help-glpk] Is this a bug I see before me?

compute the violation with 6 decimal figures, it could be *zero*. In other words, the error appears, because your model is badly formulated. Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### Re: [Bug-glpk] Dualp simplex method classifies an unbounded problem as no primal feasible

I am testing GLPK 4.36. I tried a test case that I have also used with GLPK 4.19. Maximize 40 * x1 + 60 * x2 subject to 0 = x1 0 = x2 70 = 2 * x1 + x2 40 = x1 + x2 90 = x1 + 3 * x2 This problem is primal feasible. It is

### Re: [Bug-glpk] Dualp simplex method classifies an unbounded problem as no primal feasible

I am testing GLPK 4.36. I tried a test case that I have also used with GLPK 4.19. Maximize 40 * x1 + 60 * x2 subject to 0 = x1 0 = x2 70 = 2 * x1 + x2 40 = x1 + x2 90 = x1 + 3 * x2 This problem is primal feasible. It is

### Re: [Bug-glpk] Dualp simplex method classifies an unbounded problem as no primal feasible

The documentation says: GLP_PRIMAL-use two-phase primal simplex; GLP_DUAL -use two-phase dual simplex; GLP_DUALP -use two-phase dual simplex, and if it fails, switch to the primal simplex. Your point is that the dual simplex has solved the dual problem--the dual problem is infeasible. That

### Re: [Bug-glpk] Minor patch for recent glpk up to version 4.37

Versions 4.35--4.37 of glpk have failed to build on SGI IRIX MIPS, but I only today had the time to figure out why. The problem is this definition in the native ctype.h file: #define _G 0x4000 /* Graphic characters only */ It conflicts with this piece of code in

### Re: [Bug-glpk] --wmps and --wcpxlp don't work in version 4.37

/ or from some mirror ftp sites (see http://www.gnu.org/order/ftp.html ) and build the package in usual way. Both the glpsol options must work. Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### Re: [Bug-glpk] Error in xBase driver in str2num(buf, num) == 0

to incorrect numeric data on reading csv or dbf file. There must be an error message rather than abnormal termination, however, I just missing that when was writing the code. Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman

### [Bug-glpk] Re: GLPK 4.38: example/sql/mysql_setup.sh

please, apply chmod 755 examples/sql/mysql_setup.sh The file should be executable. Done. ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### Re: [Bug-glpk] cpx_basis and adv_basis generate stderr output

this message by a more friendly one like Constructing initial basis... . Thanks. Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### [Bug-glpk] Re: [Help-glpk] Why GLPK crash when I try to solve this problem?

Hi, I'm new to GLPK and I need help. I'm trying to solve a problem with GLPK (or, at least, to write LP problem) but the solver crashes and I don't know why... I'll attach you mod and dat file: http://www.nabble.com/file/p23556429/FP.mod FP.mod http://www.nabble.com/file/p23556429/zonaE.dat

### Re: [Bug-glpk] str2num() is locale dependent

. Is locale changed intentionally in your application? Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### [Bug-glpk] Re: Bug in amd_order.c ?

I'm sorry to say I think I may have found a small bug in amd_order.c When using glpk 4.38 and I try to solve this problem with the interior point method (either null or default params) : Minimize obj: - x_4 - x_5 Subject To r_1: + x_4 - 2 x_1 = 4 r_2: + 2 x_5 + x_2 = 12

### Re: [Bug-glpk] Crash in glp_interior

I modified the introductory example from the manual to use the interior-point method: [...] It compiles and runs but finishes with a null pointer: j...@jisp:~/pure/glpk/pure-glpk$ ./ipt_test Original LP has 3 row(s), 3 column(s), and 9 non-zero(s) Working LP has 3 row(s), 6 column(s),

### Re: [Bug-glpk] Crash in glp_interior

There seems to be something wrong with the parameter block in the glp_interior call. When I define the parameter block, try to change the ordering method and pass the block to glp_interior I always receive precisely the same output including AMD ordering method. Please check your code. If

### Re: [Bug-glpk] Problem with GLPK 4.30 and later

Please forgive me if this is not in the correct format. If there is a better way to submit this report please advise me. A research group I work with has been using GLPK and CPLEX for the past four years to solve queueing network problems. Most of our work occurs during the summer.

### Re: [Bug-glpk] Typos

Hi Xypron, some typos exist in output strings. See patch below. Thank you for your attention. Best regards Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### Re: [Bug-glpk] Crash in 4.38

the timer value determined by the routine happens to be less than its value in the past. Does the error happen regularly or randomly? On which platform are you running glpk? Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org

### Re: [Bug-glpk] Incorrect result from glpk-4.39

I am writing to report what looks like a bug in glpk-4.39, that, surprisingly, is not there in glpk-4.26. Below, I first describe the problem, and its output when run with glpk-4.39 on a pc running fedora-11. It is solved incorrectly by glpk-4.39. Then, I will give the output of glpk-4.26,

### Re: [Bug-glpk] numerical instability (cycling?)

I am sure we both agree that getting into an infinite loop is not acceptable. and applying geometric mean scaling makes the instance badly scaled. What is your opinion about the Curtis-Reid scaling algorithm? I do not think that another scaling algorithm would help. The defect is in the

### Re: [Bug-glpk] 4.39 fails to produde optimal solution

Memory used: 0.1 Mb (113395 bytes) Andrew Makhorin glpkin1.lp Description: Binary data ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### Re: [Bug-glpk] 4.39 fails to produde optimal solution

Looks like large constraint coefficients cause the effect described in the paper: A. Neumaier and O. Shcherbina, Safe bounds in linear and mixed-integer programming, Math. Programming A 99 (2004), 283-296. http://www.mat.univie.ac.at/~neum/ms/mip.pdf when tightening the feasible region improves

### Re: [Bug-glpk] numerical instability (cycling?)

I do not think that another scaling algorithm would help. The defect is in the simplex solver. Could you please fix that? Would it be a lot of work? It is not so easy. Currently, if some basic variables violate their bounds due to excessive round-off errors, the primal simplex switches to

### Re: [Bug-glpk] glpsol ignores tmlim

0 149 move[2,3,3] NU 0 0 2.55832e+20 150 move[2,3,4] NU 0 0 eps Andrew Makhorin ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org

### Re: [Bug-glpk] glpk 4.39: Assertion failed: col-type == GLP_FX

with the attached lp, I get an assert in glpnpp01.c at line 634: GLPSOL: GLPK LP/MIP Solver 4.39 Reading problem data from `glpk_nppassertfail.mps'... Problem: none_lo Objective: R000 7 rows, 26 columns, 38 non-zeros 75 records were read Original LP has 7 rows, 26 columns, 38

### Re: [Bug-glpk] GLPSOL outputs MIP solution that is not LP optimal for fixed integers

Hi Xypron, I have solved the model below with glpsol.exe --fpump -m test.mod --tmlim 30 (derived from http://lists.gnu.org/archive/html/help-glpk/2009-09/msg00015.html http://lists.gnu.org/archive/html/help-glpk/2009-09/msg00015.html ) The output was + 1763: mip = 1.04149e+002 =

### Re: [Bug-glpk] GLPSOL outputs MIP solution that is not LP optimal for fixed integers

I guess what is missing either in function glp_ios_heur_sol() or in ios_feas_pump() is to solve the original problem with the integer values found. Ios_feas_pump provides a complete mip solution. I would prefer glp_ios_heur_sol to call glp_simplex. This would allow to check the feasibility

### Re: [Bug-glpk] GLPSOL outputs MIP solution that is not LP optimal for fixed integers

, a constraint is added to increment the objective by 10 % which may be more than the gap to the LP solution. Thank you for the patch. I need some time to check the code, and then I will include it in the heuristic module. Best, Andrew Makhorin

### Re: [Bug-glpk] GLPSOL outputs MIP solution that is not LP optimal for fixed integers

, a constraint is added to increment the objective by 10 % which may be more than the gap to the LP solution. See the patched version of glpios10.c attached. It will be included in the next version of the package. Could you please check the modifications once again? Thanks. Andrew Makhorin

### Re: [Bug-glpk] GLPSOL outputs MIP solution that is not LP optimal for fixed integers

the modified patch works fine with my examples. Thanks. I guess the coding after #if 0 /* modified by xypron xypron.g...@gmx.de */ up to #else should be removed from the coding as the coding is incorrect for dir == GLP_MAX. Why incorrect? It is another heuristic to choose bnd; probably

### Re: [Bug-glpk] Sensitivity Information not presented in sensitivity bounds file

I am not sure if this is a bug or not, but I am not able to get sensitivity bounds for the following simple example. Thank you for the bug report. There is a bug in the bound sensitivity routine: it works only for minimization while your instance is maximization. To avoid the bug you can

### Re: [Bug-glpk] Sensitivity Information not presented in sensitivity bounds file

the problem below can be solved by the dual simplex glpsol.exe -m test.mod --dual Yet glp_get_dual_stat() returns GLP_INFEAS dual solution is infeasible for the problem when called in glplpx03.c. The dual values for the constraints are c1: 1.00 c2: 1.00 c3: -0.00e+000

### Re: [Bug-glpk] Sensitivity Information not presented in sensitivity bounds file

Hi Xypron, the problem below can be solved by the dual simplex glpsol.exe -m test.mod --dual Yet glp_get_dual_stat() returns GLP_INFEAS dual solution is infeasible for the problem when called in glplpx03.c. The dual values for the constraints are c1: 1.00 c2: 1.00 c3:

### Re: [Bug-glpk] Sensitivity Information not presented in sensitivity bounds file

attachment). It is assumed that you have glpk version 4.39. Andrew Makhorin glpapi12.c.gz Description: GNU Zip compressed data ___ Bug-glpk mailing list Bug-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/bug-glpk

### Re: [Bug-glpk] help

glpsol -m big.mod -o a.log the attached file is model file it seems take too much time to have a result could anybody help me? Try: glpsol -m big.mod --mir Using mir cuts the solution takes about 30 secs on my machine. ___

### Re: [Bug-glpk] write error on stdout - output buffer overflow

the following model returns an error write error on stdout - output buffer overflow for {i in 1..2000} printf %6s, x; end; Currently the output buffer is only flushed when reaching a new line. For very long output lines the buffer should be flushed instead of throwing an error. Thank

### [Bug-glpk] Re: Assertion failed mip!=mip

vpm2 from miplib 2003 without any problems. See the log below. Andrew Makhorin GLPSOL: GLPK LP/MIP Solver 4.40 Parameter(s) specified in the command line: --pcost --mir vpm2.mps --log vpm2.log Reading problem data from `vpm2.mps'... Problem: VPM2 Objective: TIME 235 rows, 378 columns, 1085

### Re: [Bug-glpk] Memory allocation problem

I have been using GLPK for almost a year now to solve integer optimization problems quite satisfactorily, but I'm now encountering a serious problem. The model I'm trying to solve has 342 370 columns (variables are 3-dimensional, in the form of 134 operators x 7 work shifts x 365 days), all

### Re: [Bug-glpk] tspsol: command not found

OS: ubuntu 9.10 glpk 4.38-1 glpk-utils 4.38-1 /* This package contains the following stand-alone tools: * glpsol: LP/MIP solver * tspsol: TSP solver */ but $ tspsol -t **.tsp $ tspsol: command not found I failed to search tspsol in glpk-utils, and also can not find

### Re: [Bug-glpk] Assertion failed: str2num(buf, num) == 0 Error detected in file ..\src\glpsql.c at line 900

I got this error. ~ Assertion failed: str2num(buf, num) == 0 Error detected in file ..\src\glpsql.c at line 900 Doing this, Reading data from a query, not a table. ~ table qryCroptype IN ODBC 'DSN=Otago_mdb' 'SELECT * FROM qryCroptype':

### Re: [Bug-glpk] Assertion failed: str2num(buf, num) == 0 Error detected in file ..\src\glpsql.c at line 900

Would it be possible to put 0 for this NULL rather terminating the mathprog, just to process this query or reading table. AMPL manage to process this query or reading table with NULL without error. I think that NULL should mean missing data, like '.' in the data section, neither 0 nor error.