Sun Dec 05 12:00:00 2010 Andrew Makhorin <mao@gnu.org>

        * GLPK 4.45 (30:0:30) has been released

        * glplpx01.c

        A bug (it_cnt) in routine reset_parms was fixed.

        Thanks to Ali Baharev <ali.baharev@gmail.com> for report.

        * glpmpl03.c

        A bug (print "text\") was fixed.

        Thanks to Xypron <xypron.glpk@gmx.de> for report.

        * glpsql.c

        A precision bug was fixed.

        Thanks to Xypron <xypron.glpk@gmx.de>.

        * glpk.tex

        Some typos were corrected.

        Thanks to Robbie Morrison <robbie@actrix.co.nz>.

Thu Jun 03 12:00:00 2010 Andrew Makhorin <mao@gnu.org>

        * GLPK 4.44 (29:0:29) has been released

        * glpapi14.c glpmpl.h glpmpl01.c glpmpl03.c glpmpl04.c

        Implemented suffixes for variables and constraints.

        * glpmpl06.c

        Made changes to allow comment records in CSV files.

        * glpapi17.c

        Added and documented new API routine glp_cpp to solve Critical

        Path Problem.

Sat Feb 20 12:00:00 2010 Andrew Makhorin <mao@gnu.org>

        * GLPK 4.43 (28:0:28) has been released

        * glplib.h, glplib.c, glpenv.h, glpenv.c

        The module glpenv was split into two modules glpenv and glplib.

        * glpenv01.c, glpenv03.c, glpenv04.c, glpenv06.c

        The following new API routines were added and documented:

        glp_init_env, glp_free_env, glp_open_tee, glp_close_tee,

        glp_error (macro), glp_difftime.

        * glpapi16.c

        New API routine glp_top_sort (topological sorting of ayclic

        digraph) was added and documented.

        * glpapi17.c

        A serious bug was fixed in the routine glp_asn_prob_hall.

        * glpnpp05.c

        A bug was fixed in the LP/MIP preprocessor (hidden covering

        inequalities).

        * glpsql.c

        Some improvements were made in the table driver (NULL data).

        Thanks to Xypron <xypron.glpk@gmx.de> for contribution.

        * configure.ac

        Changes were made to use .dylib rather than .so under Mac OS.

        Thanks to Noli Sicad <nsicad@gmail.com> for testing

Wed Jan 13 12:00:00 2010 Andrew Makhorin <mao@gnu.org>

        * GLPK 4.42 (27:0:27) has been released

        * glpapi01.c, glpapi11.c, glpapi12.c, glpdmx.c

        The following new API routines were added and documented:

        glp_check_dup (check for duplicate elements in sparse matrix);

        glp_sort_matrix (sort elements of the constraint matrix);

        glp_read_prob (read problem data in GLPK format);

        glp_write_prob (write problem data in GLPK format);

        glp_analyze_bound (analyze active bound of non-basic variable);

        glp_analyze_coef (analyze obj. coefficient at basic variable);

        glp_print_ranges (print sensitivity analysis report; replaces

        lpx_print_sens_bnds).

        * glpapi20.c

        New command-line options were added to glpsol:

        --glp (read problem data in GLPK format);

        --wglp (write problem data in GLPK format);

        --lp (replaces --cpxlp);

        --wlp (replaces --wcpxlp);

        --ranges (print sensitivity analysis report).

        * glpapi06.c

        In the routine glp_init_smcp default value of the parameter

        out_frq was changed to 500 (it was 200).

        * glpipp.h, glpipp01.c, glpipp02.c

        The old MIP preprocessor module was removed.

        * glpapi09.c

        Now the MIP solver uses the new MIP preprocessor (NPP).

        * glplpx03.c

        lpx_write_opb was disabled due to replacing IPP with NPP.

        * glpnet09.c

        Kellerman's heuristic to cover edges by cliques was added.

        * glplib08.c

        Recognition of special filenames "/dev/stdin", "/dev/stdout",

        and "/dev/stderr" was added.

        * glpk.tex

        Chapter "Graph and network routines" was carried out from the

        reference manual as a separate document.

Mon Dec 21 12:00:00 2009 Andrew Makhorin <mao@gnu.org>

        * GLPK 4.41 (26:0:26) has been released

        * glpapi12.c

        The following new API routines were added:

        glp_transform_row (replaces lpx_transform_row);

        glp_transform_col (replaces lpx_transform_col);

        glp_prim_rtest (replaces lpx_prim_ratio_test);

        glp_dual_rtest (replaces lpx_dual_ratio_test).

        Note that values returned by glp_prim_rtest and glp_dual_rtest

        differ from the ones retutned by the deprecated routines.

        * glpnpp*.*

        The LP/MIP preprocessor was essentially re-implemented.

        * glpios03.c

        The feature to remove inactive cuts from the active subproblem

        was implemented.

        * glpios11.c

        The feature processing cuts stored in the cut pool was improved

        (now it uses estimation of objective degradation).

        * glpscg.*

        Obsolete implemetation of the conflict graph was removed.

        * glpmpl.h, glpmpl03.c, glpmpl04.c

        FILE was replaced by XFILE to allow using GLPK I/O routines.

        * glpsql.c, examples/sql, doc/tables.tex

        The SQL table driver was changed to allow multiple arguments

        separated by semicolon in SQL statements. Thanks to Xypron

        <xypron.glpk@gmx.de>.

        * glpk.h, glpapi14.c

        New API routine glp_time was added (not documented yet).

        * glpapi20.c

        Two new options were added to glpsol: --seed value (initialize

        pseudo-random number generator used in MathProg model with

        specified seed value), and --ini filename (use as initial basis

        previously saved with -w option).

        * examples/xyacfs.mod

        Thanks to Nigel Galloway <nigel_galloway@operamail.com> for

        contribution.

        * examples/dbf/*.*

        Thanks to Noli Sicad <nsicad@gmail.com> for contribution.

        * w32/*.*, w64/*.*

        Scripts to build GLPK with Microsoft Visual Studio 2010 were

        added. Thanks to Xypron <xypron.glpk@gmx.de> for contribution

        and testing.

Tue Nov 03 12:00:00 2009 Andrew Makhorin <mao@gnu.org>

        * GLPK 4.40 (25:0:25) has been released

        * glpdmx.c

        Two new API routines were added:

        glp_read_ccdata (read graph in DIMACS clique/coloring format);

        glp_write_ccdata (write graph in DIMACS clique/coloring format).

        Also an example file examples/sample.col was added.

        * glpapi19.c, glpnet08.c

        New API routine glp_wclique_exact was added. It is intended to

        find a maximum weight clique with the exact algorithm developed

        by Prof. P. Ostergard.

        * glpnpp02.c

        A bug was fixed in the LP preprocessor (routine npp_empty_col).

        Thanks to Stefan Vigerske <stefan@math.hu-berlin.de> for the

        bug report.

        * glpios10.c

        A bug was fixed and some improvements were made in the FPUMP

        heuristic module. Thanks to Xypron <xypron.glpk@gmx.de>.

        * glpapi12.c

        A bug was fixed in the API routine glp_warm_up (dual

        feasibility test was incorrect in maximization case). Thanks to

        Uday Venkatadri <Uday.Venkatadri@dal.ca> for the bug report.

        * glpapi16.c

        Two new API routines were added:

        glp_del_vertices (remove vertices from graph);

        glp_del_arc (remove arc from graph).

        * glpios09.c

        The hybrid pseudocost branching heuristic was included in the

        MIP solver. It is available on API level (iocp.br_tech should

        be set to GLP_BR_PCH) and in the stand-alone solver glpsol

        (via the command-line option --pcost). This heuristic may be

        useful on solving hard MIP instances.

        * glpios03.c

        The branching heuristic by Driebeck and Tomlin (used in the

        MIP solver by default) was changed to switch to branching on

        most fractional variable if an lower bound of degradation of

        the objective is close to zero for all branching candidates.

Sun Jul 26 12:00:00 2009 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.39 (24:0:24) has been released

        * glpsdf.c

        New API routines to read plain data files were added.

        * glpcpx.h, glpini.h, glpscl.h

        These headers were removed.

        * glpcpx.c

        API routines glp_read_lp and glp_write_lp to read/write files

        in CPLEX LP format were re-implemented. Now glp_write_lp

        correctly writes double-bounded (ranged) rows by introducing

        slack variables rather than by duplicating the rows. The data

        structure glp_cpxcp and routine glp_init_cpxcp were added.

        * amd/*

        The 'xfree(NULL)' bug was fixed in the AMD routines. Thanks to

        Niels Klitgord <niels@bu.edu> for the bug report.

        * glpapi16.c

        New API routines glp_set_vertex_name, glp_create_v_index,

        glp_find_vertex, and glp_delete_v_index were added.

        * glpdmx.c

        New API routines glp_read_asnprob, glp_write_asnprob,

        glp_read_ccformat, and glp_write_ccformat were added (the two

        latter routines are not documented yet).

        * glpapi18.c

        New API routines glp_check_asnprob, glp_asnprob_lp,

        glp_asnprob_okalg, and glp_asnprob_hall were added.

        * glpini01.c, glpini02.c

        The message "Crashing..." was changed to "Constructing initial

        basis..." due to suggestion by Thomas Kahle <tom111@gmx.de>.

        * glpapi14.c

        New API routines glp_printf, glp_vprintf, glp_malloc,

        glp_calloc, glp_free, and glp_assert were added.

        * glplpp.h, glplpp01.c, glplpp02.c

        Old LP presolver routines were removed. Now glp_simplex uses

        new preprocessing routines (see glpnpp).

        * glpapi12.c

        New API routine glp_warm_up was added; it replaces the routine

        lpx_warm_up.

Sat May 02 12:00:00 2009 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.38 (23:0:23) has been released

        * glpmps.c

        API routines to read/write MPS files were re-implemented.

        * glpspx02.c

        Some improvements were made in the dual simplex routine.

        * glpk.h

        New structure glp_iptcp was added.

        * glpnpp.h, glpnpp01.c, glpnpp02.c

        New LP/MIP preprocessor. Currently it includes only some basic

        routines and used only in the interior-point solver.

        * glpapi08.c

        API routine glp_interior was replaced by an improved version

        (new LP/MIP preprocessor, new ordering algorithms).

        New API routine glp_init_iptcp was added.

        API routine glp_ipt_status may return two new statuses due to

        changes in glp_interior.

        * glpsol.c

        New command-line options were added (ordering algorithm used in

        the interior-point solver).

        * amd/*.*, colamd/*.*

        Two external software modules AMD and COLAMD/SYMAMD used in the

        interior-point solver were included in the distribution.

        For details see amd/README and colamd/README.

        * glpnet03.c, glpnet04.c, glpnet05.c

        A minor bug was fixed (_G => G_). Thanks to Nelson H. F. Beebe

        <beebe@math.utah.edu> for bug report.

Sun Mar 29 12:00:00 2009 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.37 (22:0:22) has been released

        * glpk.h

        iocp.fp_heur was added to enable/disable fpump heuristic.

        * glpios10.c

        ios_feas_pump was added (feasibility pump heuristic).

        * glpsol.c

        --fpump command-line option was added.

        * glpsds.c

        Plain data set routines were added to facilitate reading plain

        data in application programs. Currently these routines are not

        in API, though declared in glpk.h.

        * glpapi08.c

        A bug was fixed in the internal routine restore. (Due to this

        bug dual solution components were computed incorrectly if the

        problem was scaled.)

        * glpapi10.c, glpapi11.c

        The following new API routines were added:

        glp_print_sol (replaces lpx_print_sol);

        glp_print_ipt (replaces lpx_print_ips);

        glp_print_mip (replaces lpx_print_mip);

        _glp_check_kkt (replaces lpx_check_kkt, lpx_check_int).

        Now the routine lpx_print_prob (deprecated) is equivalent to

        the routine glp_write_lp.

        * glpapi18.c, glpapi19.c

        The following new API routines were added:

        glp_read_graph (read graph from plain text file);

        glp_write_graph (write graph to plain text file);

        glp_weak_comp (find all weakly connected components);

        glp_strong_comp (find all strongly connected components).

        * configure.ac, Makefile.am

        Changes were made: (a) to allow using autoreconf/autoheader;

        (b) to allow building glpk in a directory other than its source

        directory. Thanks to Marco Atzeri <marco_atzeri@yahoo.it> for

        bug report.

        * examples/shiftcover.mod

        An example model in MathProg was added.

        Thanks to Larry D'Agostino <Larry.D'Agostino@gmacrescap.com>

        for contribution.

Fri Feb 06 12:00:00 2009 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.36 (21:0:21) has been released

        * glpnet06.c, glpnet07.c, glpapi19.c

        The following new API routines were added:

        glp_mincost_okalg     find minimum-cost flow with out-of-kilter

                              algorithm

        glp_maxflow_ffalg     find maximal flow with Ford-Fulkerson

                              algorithm

        * glpsol.c

        Two new command-line options were added:

        --mincost             read min-cost flow data in DIMACS format

        --maxflow             read maximum flow data in DIMACS format

        * doc/glpk.*

        New edition of the reference manual was included.

        * glpk.h

        Duplicate symbols were removed to allow using swig.

        Thanks to Kelly Westbrooks <kellywestbrooks@yahoo.com> and

        Nigel Galloway <nigel_galloway@operamail.com> for suggestion.

        * glpcpx.c

        A minor defect was fixed in the routine glp_write_lp.

        Thanks to Sebastien Briais <sbriais@free.fr> for bug report.

        * glpsql.c

        A minor bug was fixed. Thanks to Xypron <xypron.glpk@gmx.de>

        for patch.

        * examples/hashi.mod, examples/shikaku.mod

        Two example models in MathProg were added. Thanks to Sebastian

        Nowozin <nowozin@gmail.com> for contribution.

        * examples/qfit.mod, examples/yacfs.mod

        Two example models in MathProg were added. Thanks to Nigel

        Galloway <nigel_galloway@operamail.com> for contribution.

Fri Jan 09 12:00:00 2009 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.35 (20:0:20) has been released

        * glpk.h, glpapi.c, glpnet.c

        The following new API routines were added:

        glp_create_graph      create graph

        glp_set_graph_name    assign (change) graph name

        glp_add_vertices      add new vertices to graph

        glp_add_arc           add new arc to graph

        glp_erase_graph       erase graph content

        glp_delete_graph      delete graph

        glp_read_mincost      read minimum cost flow problem data in

                              DIMACS format

        glp_write_mincost     write minimum cost flow problem data in

                              DIMACS format

        glp_mincost_lp        convert minimum cost flow problem to LP

        glp_netgen            Klingman's network problem generator

        glp_gridgen           grid-like network problem generator

        glp_read_maxflow      read maximum flow problem data in DIMACS

                              format

        glp_write_maxflow     write maximum flow problem data in DIMACS

                              format

        glp_maxflow_lp        convert maximum flow problem to LP

        glp_rmfgen            Goldfarb's maximum flow problem generator

        * doc/glpk.*

        New edition of the reference manual was included.

        * examples/sample.min, examples/sample.max

        Two example data files in DIMACS format were added.

        * glplib04.c

        The statement "if (c = '\n') fflush(stdout)" was added to the

        internal routine xputc to provide "real-time" terminal output.

        Thanks to Luiz Bettoni <bettoni@cpgei.ct.utfpr.edu.br> for

        suggestion.

        * glpmpl05.c

        A minor bug was fixed in the internal routine mpl_fn_time2str.

        Thanks to Stefan Vigerske <stefan@vigerske.de> for bug report.

        * w32/makefile, w64/makefile

        The flag -O2 (/O2) was added to some makefiles.

Thu Dec 04 12:00:00 2008 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.34 (19:0:19) has been released

        * src/glpios03.c

        A bug was fixed in the internal routine branch_on. Thanks to

        Nigel Galloway <nigel_galloway@operamail.com> for bug report.

        * src/glpmpl05.c

        Three new MathProg functions were included:

        gmtime    obtaining current calendar time

        str2time  converting character string to calendar time

        time2str  converting calendar time to character string

        Thanks to Xypron <xypron.glpk@gmx.de>.

        * doc/glpk.*, doc/gmpl.*

        A new edition of the GLPK reference manual and GNU MathProg

        language description were included.

Thu Oct 30 12:00:00 2008 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.33 (18:0:18) has been released

        * glpapi*.*

        The following new API routines were added:

        glp_copy_prob         copy problem object content

        glp_exact             solve LP in exact arithmetic

                              (makes lpx_exact deprecated)

        glp_get_unbnd_ray     determine variable causing unboundedness

                              (makes lpx_get_ray_info deprecated)

        glp_interior          solve LP with interior-point method

                              (makes lpx_interior deprecated)

        * glpapi*.*

        The following new API routines for processing models written in

        the GNU Mathprog language were added to the package:

        glp_mpl_alloc_wksp    allocate the translator workspace

        glp_mpl_read_model    read and translate model section

        glp_mpl_read_data     read and translate data section

        glp_mpl_generate      generate the model

        glp_mpl_build_prob    build LP/MIP instance from the model

        glp_mpl_postsolve     postsolve the model

        glp_mpl_free_wksp     deallocate the translator workspace

        (These routines make lpx_read_model deprecated.)

        * src/glpapi17.c, examples/glpsol.c

        The stand-alone solver glpsol was re-implemented with new API

        routines.

        * src/glpsql.c

        Some bugs were fixed in the SQL table driver. Thanks to Xypron

        <xypron.glpk@gmx.de>.

        * examples/cplex/*.*

        A crude implementation of CPLEX-like interface to GLPK API was

        added to the package. See examples/cplex/README.

Fri Oct 03 12:00:00 2008 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.32 (17:0:17) has been released

        * glpmpl01.c

        A bug was fixed. Due to this bug iterated expressions having

        an indexing expression whose dummy indices are bound to some

        values, i.e. like sum{(i+1,j,k-1) in E} x[i,j,k] are evaluated

        incorrectly. Namely, current value of such expressions is not

        invalidated when corresponding dummy indices (like i and k in

        the example above) are changed, that erroneously results in the

        same value evaluated for the first time.

        * glpios03.c

        Euclidean reduction of the local objective bound was added in

        the routine glpios03.c.

        * glpapi11.c

        The following new branch-and-cut API routines were added:

        glp_ios_row_attr      determine additional row attributes;

        glp_ios_pool_size     determine current size of the cut pool;

        glp_ios_add_row       add constraint to the cut pool;

        glp_ios_del_row       delete constraint from the cut pool;

        glp_ios_clear_pool    delete all constraints from the cut pool.

        * glpapi08.c

        The following new features were included in the branch-and-cut

        solver (the API routine glp_intopt):

        MIP presolver;

        mixed cover cut generator;

        clique cut generator.

        Due to the MIP presolver glp_intopt may additionally return

        GLP_ENOPFS and GLP_ENODFS, if primal or dual infeasibility of

        LP relaxation is detected by the presolver. Also the return

        code GLP_EMIPGAP was introduced to correctly indicate that the

        mip gap tolerance is reached.

        * glplpx01.c

        Now the obsolete API routines lpx_integer and lpx_intopt are

        completely superseded by the API routine glp_intopt that makes

        them deprecated.

        * glpmpl05.c

        Now the table driver name "iODBC" can be specified as "ODBC".

        * glpmpl03.c

        A bug fixed in the routine free_dca.

        Thanks to Xypron <xypron.glpk@gmx.de>.

        * glpsql.c

        A bug was fixed in the SQL table driver.

        Thanks to Xypron <xypron.glpk@gmx.de>.

        * examples/glpsol.c

        Changes were made to allow multiple MathProg data files.

        * doc/glpk.*

        A new edition of the GLPK reference manual was included.

        * doc/tables.*

        A new edition of the supplement "Using data tables in the GNU

        MathProg language" was included.

Tue Sep 02 12:00:00 2008 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.31 (16:0:16) has been released

        * glpspx.h, glpspx01.c, glpspx02.c, glpapi06.c

        The dual simplex solver (spx_dual_opt) was replaced by a new

        implementation of the two-phase dual simplex method (spx_dual).

        Old simplex method routines (spx_prim_opt, spx_prim_feas, and

        spx_dual_opt) were removed from the package.

        * glpk.h, glpscl.h, glpscl.c, glpapi04.c

        New API routine glp_scale_prob was added. It replaces routine

        lpx_scale_prob which is deprecated.

        * glpk.h, glpini.h, glpini01.c, glpini02.c, glpapi05.c

        New API routines glp_std_basis, glp_adv_basis, glp_cpx_basis

        were added. They replace routines lpx_std_basis, lpx_adv_basis,

        lpx_cpx_basis which are deprecated.

        * glpdmp.c

        8-byte data alignment was added to the module (sufficient for

        both ILP32 and LP64 environments).

        * glplib07.c

        16-byte data alignment was added to the module to provide

        compatibility with LP64 environment (8-byte is not sufficient

        due to jmp_buf; thanks to Xypron for investigation).

        * glplpx16.c

        New version of the routine lpx_write_pb was added. Thanks to

        Oscar Gustafsson <oscarg@isy.liu.se> for the contribution.

        * w32/VC9, w64/VC9

        Makefiles and batch files were added to build GLPK under 32-

        and 64-bit Windows with Microsoft Visual Studio Express 2008.

        Thanks to Heinrich Schuchardt <heinrich.schuchardt@gmx.de> for

        the contribution and testing.

        * w32/DM, w32/OWC

        Makefiles and batch files were added to build GLPK with Digital

        Mars C/C++ 8.50 and Open Watcom C/C++ 1.6 (32-bit Windows).

Wed Aug 13 12:00:00 2008 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.30 (15:0:15) has been released

        * glpspx.h, glpspx03.c, glpapi06.c

        The primal simplex solver (spx_prim_opt, spx_prim_feas) was

        replaced by a new implementation (spx_primal), which currently

        provides the same features as the old version.

        * glpmpl01.c, glpmpl03.c

        Some changes were made in the MathProg translator to allow <,

        <=, >=, and > on comparing symbolic values. Thanks to Heinrich

        Schuchardt <heinrich.schuchardt@gmx.de> for patches.

        * glplpx10.c

        Internal routine set_d_eps in the exact LP solver was changed

        to prevent approximation errors in case of integral data.

        Thanks to Markus Pilz <pilz@cs.uni-bonn.de> for bug report.

XXX XXX XX 12:00:00 2008 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.29 (14:0:14) has been released

        * configure.ac

        The configure script was changed to disable optional features

        by default. For details see file INSTALL.

        * glpipp02.c

        A bug was fixed in the internal routine reduce_bounds. Thanks

        to Anne-Laurence Putz <anne-laurence.putz@eurodecision.com> for

        the bug report.

        * glpapi01.c

        New API routine glp_erase_prob was added.

        * glpapi13.c

        New API routines glp_read_mps and glp_write_mps were added.

        They replace API routines lpx_read_mps, lpx_read_freemps,

        lpx_write_mps, and lpx_write_freemps, which are deprecated.

        * glpapi14.c

        New API routines glp_read_lp and glp_write_lp were added. They

        replace API routines lpx_read_cpxlp and lpx_write_cpxlp, which

        are deprecated.

        * glpsql.c

        Minor bug was fixed. Thanks to Xypron <xypron.glpk@gmx.de> for

        the bug report.

Tue Mar 25 12:00:00 2008 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.28 (13:0:13) has been released

        * glplib.h, glplib.c

        Three wrapper routines xdlopen, xdlsym, and xdlclose, which

        provide the shared library support, were added. A particular

        version of these routines depends on the option --enable-dl

        passed to the configure script (see file INSTALL for details).

        Thanks to Rafael Laboissiere <rafael@debian.org> for useful

        advices concerning the shared library support.

        * glpsql.c

        A static linking to iODBC and MySQL libraries used in the

        MathProg table drivers was replaced by a dynamic linking to

        corresponding shared libraries.

        Many thanks to Heinrich Schuchardt <heinrich.schuchardt@gmx.de>

        for the contribution and to Vijay Patil <vijay.patil@gmail.com>

        for testing this feature under Windows XP.

        * glpgmp.h, glpgmp.c

        A bug (which appeared only on 64-bit platforms) was fixed.

        Thanks to Axel Simon <Axel.Simon@ens.fr> for the bug report.

        * glpapi.c

        A bug was fixed in the api routine glp_add_cols. (If the basis

        is valid, adding column keeps it valid, however, col->bind was

        set to -1 rather to 0.)

        Thanks to Cedric[FR] <fox2113@wanadoo.fr> for the bug report.

        * glplib.c

        64-bit unsigned int type glp_ulong and corresponding routines

        were replaced by 64-bit signed int type xlong_t.

        * glpk.h, glpapi.c

        The type glp_ulong was replaced by glp_long. This affects only

        the api routine glp_mem_usage.

        * glplib.c

        Compressed data file support was added. This feature requires

        the zlib data compression libraries and allows compressing and

        decompressing .gz files "on the fly".

        * glpcli.h, glpcli.c

        Command-line interface routines were added. (This feature is

        incomplete so far.)

Sun Mar 02 12:00:00 2008 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.27 (12:0:12) has been released

        * glpsql.h, glpsql.c

        Two MathProg table drivers for iODBC and MySQL contributed by

        Heinrich Schuchardt <heinrich.schuchardt@gmx.de> were added to

        the package.

        * glpmpl05.c

        Mathprog table driver for xBASE was added to the package.

        * glpmpl03.c

        A minor was fixed in the MathProg translator (if some field

        specified in the table statement is missing in corresponding

        input table, the bug causes abnormal termination). Thanks to

        Heinrich Schuchardt <heinrich.schuchardt@gmx.de> for the bug

        report.

        * glpmpl.h, glpmpl.c

        STRING data type was replaced by plain character strings.

Sun Feb 17 12:00:00 2008 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.26 (11:0:11) has been released

        * glpmpl.h, glpmpl01.c, glpmpl03.c, glpmpl05.c

        The table statement was implemented. Description of this new

        feature is given in file doc/tables.txt.

        * glpios03.c

        A bug causing zero divide error on computing euclidean norm of

        the cut coefficient vector was fixed.

Wed Dec 19 12:00:00 2007 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.25 (10:0:10) has been released

        * glpapi10.c

        Routines lpx_eval_tab_row and lpx_eval_tab_col were replaced by

        glp_eval_tab_row and glp_eval_tab_col.

        * glpios03.c, glpios05.c

        Gomory's mixed integer cuts were implemented.

        * glpscs.h, glpscs.c

        Segmented character string routines are no longer used and were

        removed from the package.

Wed Nov 21 12:00:00 2007 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.24 (9:0:9) has been released

        * src/glplpx16.c

        A bug was fixed in the routine lpx_write_cpxlp. If a variable

        x has upper bound and no lower bound, it should appear in the

        bounds section as "-inf <= x <= u", not as "x <= u". Thanks to

        Enric Rodriguez <erodri@lsi.upc.edu> for the bug report.

        * src/glpios03.c, src/glpios04.c, src/glpios05.c

        MIR (mixed integer rounding) cuts were implemented.

Sun Oct 28 12:00:00 2007 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.23 (8:0:8) has been released

        * src/glplib05.c, configure.ac

        Check for vsnprintf was added.

        * include/glppds.h, src/glppds.c

        A module to scan plain data was added.

        * src/glpapi09.c

        The following new API routines were added:

        glp_read_sol    read basic solution from text file;

        glp_write_sol   write basic solution to text file;

        glp_read_ipt    read interior-point solution from text file;

        glp_write_ipt   write interior-point solution to text file;

        glp_read_mip    read MIP solution from text file;

        glp_write_mip   write MIP solution to text file.

        * src/glpapi12.c

        Advanced API routine glp_free_env was added.

        * examples/glpsol.c

        The following three command-line options were added:

        --mipgap tol    set relative MIP gap tolerance

        -r filename     read solution from filename

        -w filename     write solution to filename

Wed Sep 19 12:00:00 2007 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.22 (7:0:7) has been released

        * src/glpios02.c

        A bug was fixed in the MIP preprocessor (ios_preprocess_node).

        Thanks to Roberto Bagnara <bagnara@cs.unipr.it> (Department of

        Mathematics, University of Parma, Italy) for the bug report.

        * src/glpios02.c

        A bug was fixed in the MIP preprocessor (col_implied_bounds),

        due to which constraint coefficients with small magnitude could

        lead to wrong implied bounds of structural variables.

        * src/glpipp02.c

        A similar bug was fixed in the routine reduce_bounds.

        * src/glpapi01.c

        A bug was fixed in the routines glp_set_mat_row and

        glp_set_mat_col. (The bug appeared due to incorrect removing

        zero elements from the row/column lists.)

        * src/glplpx14.c

        A bug was fixed in the API routines lpx_read_mps and

        lpx_read_freemps, due to which bounds of type LI specified in

        BOUNDS section were incorrectly processed.

        * src/glplib05.c

        A call to standard function vsprintf was replaced by a call to

        vsnprintf for security reasons. Many thanks to Peter T. Breuer

        <ptb@inv.it.uc3m.es> and Rafael Laboissiere <rafael@debian.org>.

Tue Aug 28 12:00:00 2007 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.21 (6:0:6) has been released

        * glpscg.h, glpscg.c

        Routines to maintain sparse cliqued graph were added.

        * glpios02.c

        MIP preprocessing routines were added.

        * glpk.h, glpios.h, glpios03.c

        New reasons for calling the callback routine were introduced

        in the MIP solver.

        * glpapi08.c

        Default backtracking strategy was changed to best local bound.

        * glpapi11.c

        New API routine glp_term_out to enable/disable terminal output

        was added.

        * glprng.h, glprng02.c

        Two routines to generate uniformly distributed pseudo-random

        floating-point numbers were added.

Thu Jul 26 12:00:00 2007 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.20 (5:0:5) has been released

        * glpk.h, glpapi08.c

        The routine lpx_integer was replaced by an equivalent routine

        glp_intopt. Also new API routine glp_init_iocp was added.

        * glpiet.h, glpiet.c

        Routines implementing the implicit enumeration tree are

        no longer used and therefore were removed from the package.

        * glpios.h, glpios01.c, glpios02, glpios03

        Routines implementing the integer optimization suite being

        replaced by a new version were removed from the package.

        * glpmip.h, glpmip01.c, glpmip02.c

        Routines implementing the B&B method being replaced by a new

        version were removed from the package.

        * glpios.h, glpios01.c, glpios02.c

        Routines implementing a new version of the integer optimization

        suite (IOS) based on the B&B method were added to the package.

        * glpk.h, glpapi10.c

        Branch-and-bound interface routines were added to the package.

        * examples/tspsol.c

        The TSP solver based on old version of the integer optimization

        suite is no more supported and was removed from the package.

        * glpipp02.c

        An error in the routine reduce_bounds was fixed; thanks to

        Graham Rockwell <bionomicron@gmail.com> for the bug report.

        * glpk.latex

        A new edition of the reference manual was included.

Thu Jul 05 12:00:00 2007 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.19 (4:0:4) has been released

        The principal change is upgrading to GPLv3.

        * glpapi01.c

        A serious bug in the routine glp_del_cols was fixed; thanks to

        Cedric[FR] <fox2113@wanadoo.fr> for the bug report. The bug

        appeared because on deleting non-basic columns the basis header

        remained valid, however, contained invalid (old) column ordinal

        numbers.

        * glpapi10.c

        A new advanced API routine glp_mem_limit was added.

        * glplpx01.c

        The case GLP_EBOUND was added to the routine lpx_simplex.

        Thanks to Cameron Kellough <Cameron.Kellough@sri.com> for the

        bug report.

        * glplpx19.c

        An API routine lpx_write_pb to write the problem instance in

        OPB (pseudo boolean) format format was added. Thanks to Oscar

        Gustafsson <oscarg@isy.liu.se> for the contribution.

        * glpsol.c

        Two new options --wpb and --wnpb were added to glpsol to write

        the problem instance in OPB format.

Mon Jun 25 12:00:00 2007 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.18 (3:0:3) has been released

        * glplib.h

        Type names ulong_t and uldiv_t were changed to glp_ulong and

        glp_uldiv to avoid conflicts with standard type names on some

        platforms. Thanks to Boris Wirtz <Boris.Wirtz@uni-oldenburg.de>

        for the bug report.

        * glpbfd.*, glpfhv.*, glplpf.*

        LP basis factorization routines were made tidy.

        * glpk.h, glpapi04.c

        The following API routines were added:

        glp_set_rii, glp_set_sjj, glp_get_rii, glp_get_sjj.

        * glpk.h, glpapi06.c

        The routine lpx_simplex was replaced by an equivalent routine

        glp_simplex. Also new API routine glp_init_smcp was added.

        * glpk.h, glpapi09.c

        The following advanced API routines were added:

        glp_bf_exists, glp_factorize, glp_bf_updated, glp_get_bfcp,

        glp_set_bfcp, glp_get_bhead, glp_get_row_bind, glp_get_col_bind,

        glp_ftran, glp_btran.

        * glpk.latex

        A new edition of the reference manual was included.

        * examples/dea.mod, examples/food.mod, examples/food2.mod

        Three examples in the MathProg language were added.

        Thanks to Sebastian Nowozin <nowozin@gmail.com>.

Sat May 26 12:00:00 2007 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.17 (2:0:2) has been released

        * glpdmp.h, glpdmp.c

        Memory pool routines were replaced by a new version.

        * glpscs.h, glpscs.c

        Segmented string routines were replaced by a new version.

        * glplpx08.c, glplpx09.c

        Now the MIP problem may have no integer columns.

        * glpapi01.c

        The routines glp_set_mat_row, glp_set_mat_col, and glp_load_mat

        were modified to allow zero elements (which are not stored in

        the constraint matrix).

        * glpscf.h, glpscf.c

        Schur complement factorization routines were implemented.

        * glplpf.h, glplpf.c

        LP basis factorization routines based on LU-factorization and

        Schur complement were implemented.

        * glplpx02.c, glplpx03.c

        New control parameter LPX_K_BFTYPE was introduced to choose the

        basis factorization type used by the simplex method routines.

        * glpsol.c

        Three new command-line options were added to choose the basis

        factorization type used by the simplex method routines: --luf,

        --cbg, and --cgr.

        * glpk.latex

        A new edition of the reference manual was included.

Sat May 05 12:00:00 2007 Andrew Makhorin <mao@mai2.rcnet.ru>

        * GLPK 4.16 (1:0:1) has been released

        * glpk.h, glpapi.c, glplpx01.c, glplpx02.c

        Names of a number basic api routines were changed and now have

        the prefix 'glp_'. To keep backward compatibility these routines

        are also available via their old names prefixed with 'lpx_'.