2004-11-07 Jody Goldberg * Release 1.3.93 2004-10-31 Jody Goldberg * Release 1.3.92 2004-10-05 Jody Goldberg * Release 1.3.91 2004-09-08 Jody Goldberg * Release 1.3.90 2004-08-29 Jody Goldberg * Release 1.3.2 2004-07-19 Jody Goldberg * Release 1.3.1 2004-03-28 Jody Goldberg * Release 1.3.0 2003-12-23 Jody Goldberg * Release 1.2.3 Fri Nov 14 12:00:00 2003 Andrew Makhorin * GLPK 4.2 has been released. * glpiet.h, glpiet.c, glpios.h, glpios1.c, glpios2.c, glpios3.c A preliminary implementation of the Integer Optimization Suite (IOS) was included in the package. Eventually IOS will replace the Implicit Enumeration Suite (IES). * glplpx.h, glplpx6d.c A dummy version of the integer optimization routine lpx_intopt was included in the package. Later this routine will replace the routine lpx_integer. * examples/glpsol.c A new command-line option --int-opt was added to the solver to call lpx_intopt rather than lpx_integer. * glpbcs.h, glpbcs1.c, glpbcs2.c Being replaced by IOS routines (see above) the Branch-and-Cut Framework (BCS) routines were removed from the package. * examples/tspsol.c Stand-alone Symmetric TSP solver was completely re-programmed using IOS routines. * glplib.h, glplib2.c, glplib4.c The random-number generator was implemented. It is based on the module GB_FLIB from the Stanford GraphBase originally developed by Donald Knuth. * glphbsm.c, glplpx8a.c, glpmps.c All calls to fopen/fclose were replaced by corresponding calls to ufopen/ufclose due to bug reports provided by Morten Welinder and . * glpmps.c The code was made re-entrant. * glplpx8b.c API routine lpx_print_sens_bnds for bounds sensitivity analysis contributed by Brady Hunsaker was added to the package. This feature is also available in glpsol via the command-line option --bounds. * contrib/jni/*.* New version of GLPK JNI (Java Native Interface) contributed by Chris Rosebrugh was added to the package. * contrib/deli/*.* GLPK DELI (Delphi Interface) contributed by Ivo van Baren was added to the package. * glplpx3.c Default method to scale the problem was changed to equilibration scaling (lp->scale = 1 in lpx_reset_parms). * glplpx6a.c Two minor (non-critical) typos were fixed due to report provided by Andrew Hamilton-Wright . * glplpp2.c An untested case (line 941) had been tested due to bug report provided by Jiri Spitz . * w32bc5.mak, w32vc6.mak, w32vc6d.mak, d32dmc.mak Several makefiles were added to allow building GLPK library for some non-GNU 32-bit platforms. Sat Aug 23 12:00:00 2003 Andrew Makhorin * GLPK 4.1 has been released. * glpmpl1.c, glpmpl3.c Some bugs were fixed in the MathProg translator due to the bug reports provided by Giles Thompson : conditional set expressions were incorrectly parsed; dimen attribute was not set by default when a set was used recursively in its own declaration; logical expressions ... in if ... then ... else ... did not work; displaying set expressions did not free memory allocated for temporary results. * glpmpl3.c (reduce_terms) Implementation of summation of linear forms over domain was improved to reduce complexity of that operation from O(n*n) to O(n*log n). The improvement was made due to a report provided by Sebastien de Menten . * glplpx6a.c (line 1056), glpmip1.c (line 641) Two minor bugs were fixed due to the bug report provided by Kendall Demaree . * glplpx.h, glplpx6a.c The method of one artificial variable implemented in the routine lpx_prim_art and used on the phase I in the glpk simplex solver has a serious defect: for some lp instances it erroneously reports that the problem has no primal feasible solution. This error appears when the column of the artificial variable, which enters the basis to make it primal feasible, has large constraint coefficients, that leads to small reduced costs of non-basic variables and premature termination of the search, i.e. to wrong conclusion that the problem has no primal feasible solution. To avoid this defect the routine lpx_prim_feas was included. It implements the method of implicit artifical variables (based on minimization of the sum of infeasibilities), which is a bit slower but much more robust. The routine lpx_prim_feas having the same functionality now is used instead the routine lpx_prim_art. * glpinv.h, glpinv.c The test used in the routine inv_update to detect low accuracy after updating LU-factorization of the basis matrix was replaced by a new, more robust test. * glplpx6c.c Selecting an active node to be solved next in the routine btrack_bestp was changed. Now, if any integer feasible solution has not been found yet, the routine chooses an active node which has the minimal sum of integer infeasibilities. * glpmip.h, glpmip1.c The additional flag int_obj was included in the structure MIPTREE used by the branch-and-bound. This flag is set in the routine mip_create_tree and used in the routine is_better. It means that the objective is integral, i.e. depends only on integer variables with integer objective coefficients. The test used in the routine check_integrality was also replaced by a new, more reasonable one. * glplpx1.c A minor bug was fixed in the routine lpx_check_name. * glpmpl.h, glpmpl4.c, glplpx8d.c The flag skip_data was added to the parameter list of the routine mpl_read_model. If this flag is set, the data section in the model file is ignored. Corresponding change was made in the routine lpx_read_model. Now, if both model and data files are specified, the data section in the model file is ignored. * glplpx8c.c A minor bug (wrong format used for writing free columns) in the routine lpx_write_lpt was fixed due to the bug report provided by Bernhard Schmidt * sample/glpsol.c The command-line parameter --tmlim, which allows limiting the solution time, was added. * doc/lang.*, doc/refman.* New edition of the GLPK documentation was included. * java-binding/*.* New version of the GLPK JNI (Java Native Interface) package was included in the distribution. * sample/lpglpk40.c A non-trivial example was added. It allows using GLPK as a base LP solver for Concorde, a program for solving Traveling Salesman Problem (TSP). For details see comments in lpglpk40.c. * sample/*.mod Some examples of LP and MIP models written in GNU MathProg were added. Tue May 06 12:00:00 2003 Andrew Makhorin * GLPK 4.0 has been released. * glpmpl.h, glpmpl1.c, glpmpl2.c, glpmpl3.c, glpmpl4.c The model translator for the GNU MathProg modeling language was implemented and included in the package. * glplpx.h, glplpx8d.c The api routine lpx_read_model, which is an interface to the MathProg translator, was included in the package. * glplpx.h, glplpx8a.c The api routine lpx_print_prob for writing LP/MIP problem data in plain text format was included in the package. * sample/glpsol.c New version of the GLPK stand-alone LP/MIP solver that supports the GNU MathProg modeling language was implemented. * doc/lang.latex, doc/lang.dvi, doc/lang.ps The document "GLPK: Modeling Language GNU MathProg" was included in the package. * doc/refman.latex, doc/refman.dvi, doc/refman.ps New edition of the GLPK Reference Manual was included in the package. * glplpx8c.c A bug in the api routine lpx_write_lpt was fixed. Due to that bug an addressing error occured in the routine if the objective function has the non-zero constant term. * glplan.h, glplan1.c, glplan2.c, glplan3.c, glplan4.c, * glplan5.c, glplan6.c, glplan7.c, glplan8.c, glplpx8b.c All modules of the translator for the GLPK/L modeling language were removed from the package, because GLPK/L being completely superseded by GNU MathProg is no more supported. Tue Mar 25 12:00:00 2003 Andrew Makhorin * GLPK 3.3 has been released. * glplpp.h, glplpp1.c, glplpp2.c An implementation of the built-in LP presolver was added to the package. * glplpx.h The flag presol was added to the structure LPX. This flag tells the lpx_simplex whether the built-in LP presolver should be used or not. By default this flag is off. Also three macros (namely LPX_E_NOPFS, LPX_E_NODFS, and LPX_K_PRESOL) that concern using the LP presolver were introduced. * glplpx3.c, glplpx6a.c These modules was changed to use the built-in LP presolver. * sample/glpsol.c Command line options --presol and --nopresol that concern using the LP presolver were added to the stand-alone LP/MIP solver. * glplan1.c This module was changed to allow declaring sets like A[1:10] in the models written in the GLPK/L modeling language. * doc/refman.latex, doc/lang.latex New editions of the documents "GLPK User's Guide" and "GLPK/L Modeling Language" were included in the distribution. * java-binding/*.* The package GLPK JNI (Java Native Interface) implementing Java binding for GLPK was included in the distribution. This package was developed and programmed by Yuri Victorovich . Tue Feb 18 12:00:00 2003 Andrew Makhorin * GLPK 3.2.4 has been released. * glplpx6b.c The code was changed to allow auxiliary variables have non-zero objective coefficients. Also a minor bug was fixed (the constant term was not considered on displaying the objective function value). * sample/glpsol.c The code was changed to fix a bug (the command-line option 'bfs' was not recognized). The bug was fixed due to report provided by Olivier . * glplpt.c The code was changed to fix a bug (binary variables were treated erroneously as integer ones). * glplpx6b.c The code was changed to fix a bug (variables that have no lower bounds were incorrectly processed on converting to the standard formulation). The bug was fixed due to report kindly provided by Kjell Eikland . Mon Nov 11 12:00:00 2002 Andrew Makhorin * GLPK 3.2.3 has been released. * glpmip.h, glpmip1.c A preliminary implementation of the branch-and-bound driver based on the implicit enumeration suite (glpies) was added to the package. This module is not documented yet. * glplpx6c.c A new implementation of the api routine lpx_integer which now is based on the b&b driver (see glpmip above) was included in the package. This new implementation has exactly the same functionality as the old version and therefore all changes are transparent to the api user. * glpbbm.h, glpbbm.c * glprsm.h, glprsm1.c, glprsm2.c * glplp.h, glplp.c These modules were removed from the package, because they were used only in the old version of the routine lpx_integer, which was replaced by the new version (see glplpx6c above). * glplpx.h, glplpx6a.c The api routine lpx_check_kkt was included in the package and its description was added in the reference manual. This routine allows checking Karush-Kuhn-Tucker optimality conditions for an LP solution. * glplpx.h, glplpx8a.c Now the api routine lpx_print_sol also prints information about "solution quality" obtained via the api routine lpx_check_kkt. * glplpx.h, glplpx8a.c New api routines lpx_read_bas and lpx_write_bas were included in the package and documented. The routine lpx_write_bas allows writing a current basis from an LP object to a text file in the MPS format. The routine lpx_read_bas allows reading a basis prepared in the MPS format from a text file into an LP object. * glplpt.c The parsing routine which reads LP problem data prepared in the CPLEX LP format was modified to allow specifying lower bounds of variables also in the form 'variable >= lower bound' (in the bounds section). This modification was made due to a notice provided by Ivan Luzzi . * glplpx.h, glplpx8c.c The api routine lpx_write_lpt which allows writing LP problem data from an LP object to a text file using the CPLEX LP format was included in the package and documented. * glplpx.h, glplpx3.c The control parameter LPX_K_LPTORIG that affects the behavior of the api routine lpx_write_lpt was introduced. * glplan6.c The semantics of the language GLPK/L was changed to allow selection in case when not all mute letters of a predicate (the operand that follows the keyword 'where') are presented in a parameter (the operand that precedes the keyword 'where'), i.e. to allow writing something like this: y[j] := sum(i, x[i] where p[i,j]); The paragraph "Selection" in the langauge description (page 25) was also correspondingly changed. This change of the language semantics was undertaken due to a notice provided by Peter Lee . * sample/hwd.lpm A nice example of LP model written in GLPK/L and contributed by Peter Lee was included in the package. * glplpx6b.c The api routine lpx_interior was modified: a) to compute dual values for all structural as well as auxiliary variables; b) to allow specifying non-zero objective coefficients at auxiliary variables. * sample/glpsol.c Three new command-line options were added to the solver, which are: --plain, --orig, and --wrlpt. Mon Oct 14 12:00:00 2002 Andrew Makhorin * GLPK 3.2.2 has been released. * glplpt.h, glplpt.c A module that reads LP/MIP problem data in CPLEX LP format was implemented. * glplpx8c.c An api routine lpx_read_lpt that reads LP/MIP problem data in CPLEX LP format was implemented. * sample/glpsol.c, sample/plan.lpt A new command-line option '--lpt' that allows reading LP/MIP problem data in CPLEX LP format was added to the solver. * doc/refman.latex, doc/refman.dvi, doc/refman.ps A new edition of the Reference Manual was included. * source/*.c Casting to (unsigned char) was added in some calls to the classification functions (isalpha, etc.). The bug was fixed due to report provided by Morten Welinder . * glplpx8a.c The local routine mps_numb used in the routine lpx_write_mps was modified to correctly format floating-point numbers that have two digits in the decimal exponent. The bug was fixed due to report provided by Vlahos Kiriakos . * glplan.h, glplan1.c, ..., glplan8.c Several serious bugs were fixed in the language processor due to reports provided by : (a) a static search tree used to find sparse array elements was sometimes overwritten that caused the message 'assertion failed' to appear; the bug was fixed by creating separate search trees in parsing routines; (b) a variable declared using the predicate-controlled variable declaration statement had wrong order of domain sets, because the variable array was built as a copy of the predicate array; the bug was fixed by using the internal routine transpose that coordinates mute letters (and therefore domain sets) on copying sparse arrays; (c) sometimes assignment statements like x[#a,#b,#c] := ... was incorrectly processed; the bug was fixed by including an appropriate check into the internal routine assign_stmt. * glp_simplex.c An additional check to see if all lower bounds are not greater than corresponding upper bounds was included in the routine to prevent wrong results to appear. Such incorrectness sometimes was not detected, namely, when variables with such bounds were non-basic and never entered the basis. * glpspx1.c Maximal number of simplex iterations before reinversion was decreased from 100 to 50. This allowed to improve accuracy and, that is more important, to reduce the solution time for many serial lp problems approximately 1.5--2 times. * glpspx2.c A check to see if all elements in the column chosen to enter the basis are close to zero in the routine spx_prim_chuzr was temporarily removed because this check gave wrong conclusion in case when the corresponding non-basic variable had zero column in the constraint matrix. An analogous check to see if all elements in the row chosen to leave the basis are close to zero in the routine spx_dual_chuzc was also temporarily removed on the same reason. The bug was fixed due to reports provided by Flavio Keidi Miyazawa and Vlahos Kiriakos . Mon Aug 12 12:00:00 2002 Andrew Makhorin * GLPK 3.2.1 has been released. * glpbcs.h, glpbcs1.c, glpbcs2.c * glpies.h, glpies1.c, glpies2.c, glpies3.c A preliminary implementation of the branch-and-cut framework was included in the package. * doc/brcut.txt The document "GLPK: A Preliminary Implementation of the Branch-And-Cut Framework" was included in the distribution. * sample/tspsol.c An illustrative program for solving symmetric TSP based on the branch-and-cut method was included in the package. * glpdmp.h, glpdmp.c A new, re-enterable version of routines for managing dynamic memory pools was included in the package. * glpavl.h, glpavl.c A new, re-enterable version of routines for managing AVL search trees was included in the package. * glplib.h, glplib2.c Two new low-level routines ufopen and ufclose were included in the package. * glplpx.h, glplpx7.c The following new api routines were added: lpx_eval_activity, lpx_eval_red_cost, lpx_reduce_form, lpx_mixed_gomory. * glptsp.h, glptsp.c A module for reading TSP data using TSPLIB format was included in the package. Mon Jul 15 12:00:00 2002 Andrew Makhorin * GLPK 3.2 has been released. * glplpx.h, glplpx1.c, glplpx2.c The identifier 'class' (used as a member name in the structure LPX and as an argument name in the routine lpx_set_class) was changed to 'clss' in order to avoid conflicts with C++ reserved words. * glpk.h, glplpx.h, glplpx1.c, glplpx2.c, glplpx6a.c, * glplpx6b.c, glplpx6c.c, glplpx7.c, glplpx8.c The following new api routines were added: lpx_set_obj_name, lpx_get_obj_name, lpx_get_row_mark, lpx_get_col_mark, lpx_transform_row, lpx_transform_col, lpx_prim_ratio_test, lpx_dual_ratio_test, lpx_interior, lpx_get_ips_stat, lpx_get_ips_row, lpx_get_ips_col, lpx_get_ips_obj, lpx_read_lpm, lpx_write_mps, lpx_print_ips. * glpsol.c The solver was completely re-programmed using new api routines. * lang.latex, lang.dvi, lang.ps New edition of the document "GLPK: Modeling Language GLPK/L" was included in the distribution. * refman.latex, refman.dvi, refman.ps New edition of the document "GLPK: Reference Manual" (which contains descriptions of all new api routines) was included in the distribution. * glpapi.h, glpapi1.c, glpapi2.c, glpapi3.c, glpapi4.c These files (which contain old api routines) were removed from the package. * glpipm1.c, glpipm2.c The file glpipm1.c was renamed to glpipm.c. The file glpipm2.c was used only by old api routines and therefore was removed from the package. * language.texinfo Old version of the document "GLPK: Modeling Language GLPK/L" was removed from the distribution. Mon May 27 12:00:00 2002 Andrew Makhorin * GLPK 3.1 has been released. * glplpx.h, glplpx1.c, glplpx2.c, glplpx3.c, glplpx4.c, * glplpx5.c, glplpx6.c, glplpx7.c, glplpx8.c A preliminary implementation of new API routines was completed. * refman.latex, refman.dvi, refman.ps A draft edition of the document "GLPK Reference Manual", which describes new API routines, was included. * glplib3.c A bug in measuring long time intervals was fixed up. * glprsm3.c This module contains some obsolete routines not longer used and therefore it was removed from the package (into the subdirectory 'oldsrc'). * glprsm.h Some declarations related to the module 'glprsm3.c' (see above) were removed. * guide.texinfo The document "GLPK User's Guide" describing old API routines was removed from the package (into the subdirectory 'oldsrc'). * newapi.txt The document "New GLPK API Routines" was removed at all, because it is superseded by the new reference manual (see above). Mon May 13 12:00:00 2002 Andrew Makhorin * GLPK 3.0.8 has been released. * glplpx.h, glplpx1.c, glplpx2.c, glplpx3.c, glplpx4.c, * glplpx5.c, glplpx6.c, glplpx7.c A preliminary (currently incomplete) implementation of new api routines was included. * sample/newsamp.c A sample program for the new api routines was included. * newapi.txt A draft of the document "New GLPK API Routines" was included. * glpapi2.c, glpapi5.c, glpapi6.c These modules (which contain the api routines glp_call_rsm1, glp_simplex1, glp_pivot_in, glp_pivot_out) were removed from the package (to the subdirectory 'oldsrc') since these routines are functionally superseded by the new api routines. * glpk.h, glpapi2.c, glpapi3.c, glpapi4.c The api routines glp_simplex2, glp_call_ipm1, glp_call_bbm1 were renamed to glp_simplex, glp_interior, glp_integer, respectively. * sample/glpsol.c Some command-line options (which got obsolete due to the recent changes in api) were excluded. * doc/guide.texinfo New edition of the document "GLPK User's Guide" was included in the distribution to reflect the changes in some api routines. * doc/libref.texinfo This document was removed from the package (to the subdirectory 'oldsrc') since it describes the library routines, most of which got obsolete and no longer used. * Makefile.in A minor bug was fixed up due to bug report from Hans Schwengeler . Mon Apr 22 12:00:00 2002 Andrew Makhorin * GLPK 3.0.7 has been released. * glpduff.h, glpduff.c, glpspx.h, glpspx1.c, glpspx2.c, * glpapi7.c These modules were replaced by a new implementation of the simplex method and therefore they were removed from the package (however they still can be found in the subdirectory 'oldsrc'). * glprsm1.c The routine crash_aa was replaced by a new implementation and therefore it was removed from the file 'glprsm1.c'. * glplpx.h, glplpx.c, glpspx.h, glpspx1.c, glpspx2.c, glpspx3.c, * glpspx4.c, glpapi7.c New (currently incomplete) implementation of the simplex method components was included in the package. Thu Mar 28 12:00:00 2002 Andrew Makhorin * GLPK 3.0.6 has been released. * glpluf.h, glpluf.c, glpinv.h, glpinv.c New version of LU-factorization and basis maintenance routines (based on Forrest-Tomlin updating technique) was implemented. * glpeta.h, glpeta.c, glpfhv.h, glpfhv.c, glpgel.h, glpgel.c, * glppfi.h, glppfi.c, glprfi.h, glprfi.c These routines implement some other forms of the basis matrix. Now they became obsolete being functionally superseded by the new version of basis maintenance routines (see above) and were removed from the package (however they still can be found in the subdirectory 'oldsrc'). * glpbbm.c, glprsm.h, glprsm1.h, glprsm2.h, glpspx.h, glpspx2.c, * glprsm2.c, glpsol.c Necessary changes were made in order to use the new version of basis maintenance routines. Tue Jan 29 12:00:00 2002 Andrew Makhorin * GLPK 3.0.5 has been released. Structure of the package was re-organized in order to simplify its maintenance. * doc/guide.texinfo New edition of the document "GLPK User's Guide" was included in the distribution. Now the document includes descriptions of some additional API routines recently added to the package. * doc/newapi.txt The document "Additional GLPK API Routines" was removed from the distribution, because the corresponding material was included in the user's guide (see above). Mon Dec 10 12:00:00 2001 Andrew Makhorin * GLPK 3.0.4 has been released. * glpspx.h, glpspx1.c, glpspx2.c, glpapi/glp_simplex2.h A new, more efficient version of the two-phase primal simplex method was implemented (advanced initial basis, projected steepest edge, recursive computations of solution components). * glpapi/glp_call_bbm1.c Now LP relaxation can be solved either using rsm1_driver(), or using glp_simplex2(). The choice is controlled by the parameter 'meth' (a member of struct bbm1). * sample/glpsol.c The new implementation of the simplex method is now used by default. The old version is available via --old-sim option. * glpmat/gm_scaling.c Now this routine displays only two lines: an initial "quality" and a final "quality". * glplp/prepro_lp.c Identifiers 'fmin' and 'fmax' renamed to 'f_min' and 'f_max' in order to avoid conflict with . The bug was fixed due to report provided by Sami Farin . Wed Oct 03 12:00:00 2001 Andrew Makhorin * GLPK 3.0.3 has been released. * glprsm/harris_row.c, glprsm/harris_col.c The relative tolerance used on the first pass of the two-pass ratio test was replaced by the absolute tolerance. * glprsm/rsm_primal.c, glprsm/rsm_feas.c, glprsm/rsm_dual.c The absolute tolerance passed to the two-pass ratio test routine was decaresed (for both primal and dual simplex). These changes were made in order to improve numerical stability of the simplex method. * glprsm/glp_call_rsm1.c, glprsm/glp_call_bbm1.c, * glprsm/glp_simplex1, glprsm/glp_pivoting.c Default form of the inverse was changed from RFI to AFI. Mon Sep 24 12:00:00 2001 Andrew Makhorin * GLPK 3.0.2 has been released. * glpfhv.h, glpfhv.c New version of the basis maintaining routines was implemented. These routines, which are based on so called FHV-factorization (a variety of LU-factorization) and Gustavson's data structures, perform the main operations on the basis matrix faster at the expense of some worsening numerical accuracy. * glprsm.h, glprsm/afi.c The routines, which implement AFI (Advanced Form of the Inverse) based on FHV-factorization, were added to the package. This new form is available via the parameter form = 3 (on API level) or via the option --afi (in GLPSOL solver). * EFI was renamed to PFI In order to correct terminology the acronym EFI (Elimination Form of the Inverse) was replaced by PFI (Product Form of the Inverse) everywhere in the source code and the documentation. * glpset/umalloc.c, glpset/ucalloc.c * glpset/get_atom.c, glpset/get_atomv.c These memory management routines were changed in order *not* to clear allocated memory blocks by binary zeros. Wed Aug 01 12:00:00 2001 Andrew Makhorin * GLPK 3.0.1 has been released. * glpapi/old_api.c, glplp/extract_lp.c, store_lpsol.c Old API routines were deleted from the package. * include/glpk.h, include/glpapi.h, include/glplp.h Specifications of old API routines and data structures were removed from the headers. * sample/glpsol.c New version of the stand-alone solver GLPSOL that now uses new API routines was implemented. * glpapi/glp_set_row_fctr.c, glpapi/glp_set_col_fctr.c, * glpapi/glp_get_row_fctr.c, glpapi/glp_get_col_fctr.c, * glpapi/glp_scale_prob.c Scaling routines were added. * glpapi/glp_write_mps.c The routine for writing problem data in MPS format was added. * glpapi/glp_simplex1.c Comprehensive driver to the simplex method was added. * glpapi/glp_pivoting.c The routines glp_pivot_in() and glp_pivot_out() intended for basis maintaining were added. * glprsm/create_rsm.c, glprsm/delete_rsm.c, glprsm/scale_rsm.c, * glprsm/build_basis.c Additional low level routines related to the simplex method were added. * glpk.h, glpapi.h, glprsm.h Additional specifications for new routines and data structures were added. * sample/lpglpk30.c A non-trivial example was added. It allows using GLPK as a base LP solver for Concorde, a program for solving Traveling Salesman Problem (TSP). For details see comments in 'lpglpk30.c'. * doc/newapi.txt The document "Additional GLPK API Routines" that describes some new API routines was included. Thu Jul 19 12:00:00 2001 Andrew Makhorin * GLPK 3.0 has been released. Now GLPK is provided with new API, which is intended for using the package in more complex algorithmic schemes. * glpapi/old_api.c All routines related to old API were gathered in one file named 'old_api.c'. * glpapi/*.c These routines that implement new API were added to the package. * include/glpk.h, include/glpapi.h Specifications of new API routines and data structures were added to these headers. Specifications of old API routines and data structures were locked by #ifdef GLP_OLD_API directive. * doc/guide.texinfo New edition of the document "GLPK User's Guide" that correspond to new API was included. Thu Jun 14 12:00:00 2001 Andrew Makhorin * GLPK 2.4.1 has been released. * doc/glpk_ml.texinfo The new document "Modeling Language GLPK/L" was included. * doc/glpk_ug.texinfo New edition of the document "GLPK User's Guide" was included. * doc/language.txt The preliminary document "GLPK/L Modeling Language: A Brief description" was removed from the distribution, because it has been replaced by the new document "Modeling Language GLPK/L". * glplang/l_spar.c The routine comparison() was re-programmed in order to implement the relation operation as specified in the language description. * glpmip.h, glpmip/*.c The partition 'glpmip' was renamed to 'glpbbm'. Thu May 10 12:00:00 2001 Andrew Makhorin * GLPK 2.4 has been released. Now GLPK includes an implementation of a preliminary version of the GLPK/L modeling language. * glplang.h, glplang/*.c The header 'glplang.h' and a set of routines that implements the GLPK/L language processor (the partition 'glplang') were added to the package. * doc/language.txt The document "GLPK/L Modeling Language: A Brief Description (Supplement to GLPK User's Guide)" in plain text format was included in the package (see the file 'language.txt' in the subdirectory 'doc' of the distribution). * ex/model1.lpm, ex/model2.lpm Two examples of model descriptions written in GLPK/L were added to the package. * sample/glpsol.c This program was modified in order: a) to allow processing model description written in GLPK/L; b) to allow solving pure LP problem using the interior point method. * sample/glpipm.c This program was removed from the package, because its function was passed to the GLPSOL solver. * Makefile.in This file was changed in order to install the GLPSOL solver executable. Mon Apr 09 12:00:00 2001 Andrew Makhorin * GLPK 2.3 has been released. * glpmip.h, glpmip/*.c These routines (that implement the branch-and-bound method) were re-programmed in order to improve robustness of implementation. In particular, heuristic routines were carried out from the main driver routine. Additional GLPK API routines were documented. New edition of the document "GLPK User's Guide" was included in the package. The preliminary document "Mixed Integer Programming Using GLPK Version 2.2 (Supplement to GLPK User's Guide)" was removed from the package, because this material was included in GLPK User's Guide. Thu Mar 15 12:00:00 2001 Andrew Makhorin * GLPK 2.2 has been released. Now GLPK includes a tentative implementation of the branch-and-bound procedure based on the dual simplex method for mixed integer linear programming (MIP). The preliminary document "Mixed Integer Programming Using GLPK Version 2.2 (Supplement to GLPK User's Guide)" was included into the package in plain text format (see the file 'mip.txt' in the subdirectory 'doc' of the distribution). * glpmip.h, glpmip/*.c, glpapi/glp_integer.c These routines (that implement the branch-and-bound method) were added to the package. * sample/glpsol.c This program was modified in order to allow solving LP and MIP problems. * glprsm/rsm_primal.c, glprsm/rsm_dual.c, glprsm/rsm_feas.c, * glprsm/rsm1_driver.c These routines (which are drivers to basic components of the revised simplex method) were added to the package. Mon Feb 19 12:00:00 2001 Andrew Makhorin * GLPK 2.1 has been released. * glprsm.h, glprsm/*.c These routines (that implement components of the revised simplex method) were re-programmed and documented. The document "GLPK Implementation of the Revised Simplex Method" was included into the package. Thu Jan 25 12:00:00 2001 Andrew Makhorin * GLPK 2.0 has been released. Now GLPK includes a tentative implementation of the primal-dual interior point method for large-scale linear programming (for more details see the file `NEWS' in the distribution). A number of routines related to the interior point method were added to the package. * insist.c The routine `insist' and the macro of the same name were introduced into the package in order to replace the standard macro `assert'. Some routines require the expression specified in the `assert' macro to be evaluated, but compiling the package with NDEBUG option prevents from that. This bug was fixed due to bug report provided by Peter A. Huegler . * Makefile.in Minor bug was fixed due to a patch provided by Alexandre Oliva . Wed Jan 10 12:00:00 2001 Andrew Makhorin * GLPK 1.1.2 has been released. * umalloc.c, ufree.c, create_pool.c, get_atom.c, get_atomv.c These routines were changed in order to fix a bug due to report provided by Andrew Hood . Because of this bug data alignment error occured on the Sparc computer. Tue Dec 14 12:00:00 2000 Andrew Makhorin * GLPK 1.1.1 has been released. Minor bug was fixed in `Makefile.in'. GLPK Library Reference was included. Mon Nov 27 12:00:00 2000 Andrew Makhorin * GLPK 1.1 has been released. Minor changes were made in order to co-ordinate GLPK routines and their descriptions. GLPK User's Guide was included. Fri Oct 20 12:00:00 2000 Andrew Makhorin * GLPK 1.0 has been released.