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GAMS 23.1 发布！ (下载最新试用版) 
20090716
广州博脉 
什么是 GAMS ？ 请浏览 show_software.aspx?pName=GAMS w_w_w_.__p__o__mi__n__e_._c_o_m_ 需要下载试用，请填写 产品咨询表 www._p_o_mi_n_e_._c_o_m_ GAMS 23.1 的新特性：  ww_w__.po_mi_ne_.c__o_m Acknowledgments We would like to thank all of our users who have reported problems and made suggestions for improving this release. In particular, we thank Anibal Blanco, Wietse Dol, Arne Drud, Josef Kallrath, Erwin Kalvelagen, Niclas Mattsson, Bruce McCarl, Dominique van der Mensbrugghe, Renger van Nieuwkoop, Stefan Vigerske, and Tongxin Zheng. w_ww_.__po__mi__n_e_.c__o__m_ New Platform (64Bit) Intel Mac ww_w.__p__o_m_i__n__e_._co__m GAMS System GAMS Default Upper Bound on Integer Variables The default upper bound on integer variables has changed from 100 to +INF. Since some solve steps in a GAMS applications may inadvertently depend on the previous default value of 100, a the compatibility option, the GAMS parameter PF4=n, has been introduced to control what values will be passed to the solver. If the GAMS parameter PF4 is not used (a value of PF4=1 is assumed) the solve steps will work as in previous releases. w_ww_._po__m_i_n_e__.com_ Pf4=0: The new default upper bound of +INF will be passed to the solver. Pf4=1: The value of 100 instead of +INF will be passed to the solver. The solvers will operate as with older GAMS versions. In addition messages will be written to the log and listing to report on the number of integer or semiinteger variables which had the new default bound of +INF reset to 100. PF4=2: The new default values of +INF will be used as with PF4=0. When a solution is returned to GAMS and the level value of an integer variable exceeds the old bound value of 100, a message will be written to the log and listing. PF4=3: The same as PF4=2 with an additional execution error issued if the solution reports a level value greater than 100 for any integer variable with a default bound of +INF. Setting PF4 values to 2 and 3 is a convenient way to test if the application relies on the previous default bounds of 100. Future releases may use PF4=0 as the default. w_ww__.p_o_m_ine__._c_o_m__ An historic note: when GAMS was first introduced, some MIP solvers could only handle binary variable and GAMS applied transformations to simulate integers by using a power expansions. In addition, MIP solvers with integer variables imposed different restrictions on the largest upper bound value. Finally, solvers like DICOPT introduced integer cuts during the solution process, needing some finite upper bound on integer variables. What was once a good choice, turned over time into a source of confusion or resulted in unexpected model behavior. w__w_w_.__p_om_in_e.c__o__m__ Default Iteration Limit The default iteration limit (IterLim) has been increased from 10000 to 2e9. Setting IterLim to INF will not work since it is treated as an integer by GAMS and many solvers. Some solver, e.g. GAMS/Gurobi, recognize 2e9 and set the solver iteration limit to infinity. w__ww_.po_min_e__._co_m Enhanced Profiling Options In addition to PROFILE=n and PROFILETOL=r, a new GAMS parameter PROFILEFILE=file has been introduced to write profiling information to a text file with some fixed format which can easily be imported into a spreadsheet for further analysis. w_w_w.__pom_in_e_.__c_o__m_ 1 1 0.000 ExecInit 139 15 0.000 Assignment cnf 139 13 0.000 Assignment cnf . . . . . . . . . . . . 3549 432 0.000 Equation nbal 3621 39489 0.032 Solve Fini wsisn 3621 1 0.062 GAMS Fini 1 1 0.000 ExecInit 3621 1 0.047 Solve Read wsisn 3621 1 0.000 GAMS Fini w_ww__._p_om_in_e_.__co_m_ A summary report of the ten slowest execution steps will be written to the log and listing. w_ww__._p_o_m_in__e._c_om__  Profile Summary (184 records processed) 0.062 3621 GAMS Fini 0.047 3621 Solve Read wsisn 0.046 3529 Equation divcnlsea (86) 0.032 3621 Solve Fini wsisn (39489) 0.016 3274 Assignment wnr (2502) 0.016 3447 Equation cost (15) 0.016 3475 Equation laborc (180) 0.016 3519 Equation waterbaln (180) 0.016 3546 Equation subirrc (84) 0.015 3030 Assignment gwtsa (273) w_w_w.__p_o_m_in__e.co__m The timing on slow data definitions and gdx loads during compilation will be profiled as well. w_w__w._p_om_i__n_e.__c__om__ Macros Added a line continuation character (\) for macro definitions. See test model macro02. w_w_w.p_omin_e._c_om_ Other Faster reading of data statements that are not sorted Reduced memory usage for projections GDX handles IEEE special values GAMS Data Utilities GDXDIFF Added FldOnly and DiffOnly parameters to write different formats Protection against overwriting an input file GDXVIEWER Fixed problem with cubed view GDXXRW Added RWAIT parameter to specify a delay to open Excel to avoid not ready problems Added CheckDate option to regenerate output only if input is more recent than output file SCENRED2 A libinclude file runscenred2 has been added to make the communication with Scenred2 simpler. See example srpchase. GAMS IDE Changed the interface for dealing with tabs Tabs expanded to spaces will mark the file as modified Added command to select text from current position to a text marker Added checks to see if IDE is visible on the monitor Move and Size are available on TaskBar icon Documentation Updated McCarl GAMS User's Guide Solvers AlphaECP New libraries 1.75.03 CoinOR New solver CoinCouenne CoinCouenne is a global optimization solver for nonconvex mixed integer nonlinear programs, similar to the commercial solvers BARON and LindoGlobal. The solver is still in an experimental phase and is hidden in the GAMS system. New libraries Cbc 2.3 Glpk 4.37 Ipopt 3.6 Scip now uses Clp 1.10 EMP Disjunctive programs can be solved via the following alternative automated reformulations without changes to the model w_w_w._p__om_i_n_e__._c_o_m Convex Hull BigM CPLEX indicators Examples w__w__w.pomin_e.__c__o__m_ EMP Library sequence (20): Sequencing on a single machine Model Library bilinear (346): Convexification of bilinear term binary times x GUROBI New libraries 1.1 w_w_w__.p_o_m__i_n_e_._c_om KNITRO New libraries 6.0 w_w__w_._po_mi_n_e._c_o_m__ Introduces MINLP capability: binary and integer variables are supported. Two algorithms are available, a nonlinear branch and bound method and an implementation of the hybrid QuesadaGrossman method for convex MINLP. The Knitro MINLP code is designed for convex mixed integer programming and is a heuristic for nonconvex problems. General performance improvements for both the activeset and interiorpoint/barrier solvers Reorganized options into groups: general, barrier and MINLP. MOSEK New libraries 5.0 rev 127 w__ww_.__pomine__.__c_o_m__ Incore communication solver links Support of COINBONMIND, COINCBCD, COINIPOPTD and LGOD as incore communication solvers. Where a traditional link already exists, the newer incore link version has a â€œDâ€ appended to the name (D for DLL). These incore links are very similar to their traditional predecessors. They may lack some functionality but offer incore communication between GAMS and the solver, making potentially large model scratch files unnecessary. This can save time if you solve many models in your GAMS program. w_w__w_._p_o_m__i_n_e._c__o__m Model Libraries GAMS Data Library Portfolio (68): Determines an efficient frontier in Excel, using the GDX DLL (vba API) and the GAMS executable Sudoku (69): Solve a Sudoku in Excel, using the GDX DLL (vba API) and the GAMS executable Samurai (70): Solve a Samurai Sudoku in Excel, using the GDX DLL (vba API) and the GAMS executable Samurai2 (71): Solve a Samurai Sudoku in Excel, using the GDX and GAMSX DLL (vba API) CHP (72): Optimize combined heat and power generation in Excel, using vba API (gamsx and opt) and GDXXRW CHP2 (73): Optimize combined heat and power generation in Excel, using vba API (gamsx, opt and gdx) GAMS EMP Library zerofunc (18): Match unmatched vars with zero functions in VI traffic2 (19): Traffic Assignment Model sequence (20): Sequencing on a single machine GAMS Model Library secure (343): Secure Work Files  Example 2 srpchase (344): Scenario Tree Construction Example tsp5 (345): Traveling Salesman Problem  Five bilinear (346): Convexification of bilinear term binary times x solveopt (347): option solveopt explained GAMS Test Library minos01 (433) : MINOS test suite  anticycling via expand frequency scnred02 (434) : Scenred2 test  tree reduction and zero values empvi05 (435) : Test for EMP's treatment of an odd variable nlcode3 (436) : Wrong NL code generation for odd case set8 (437) : Test the set.id set#id #id data macros nlcode4 (438) : More NL testing when code is deleted compile7 (439) : Test and document some system.XXX macros mcp09 (440) : Test inequalities with infinite bounds empadj01 (441) : Test for EMPs AdjustEqu/NYslp option emp05 (442) : Test for handling of constant equations examin03 (443) : EXAMINER test suite  test returnInitPoint option compile8 (444) : Test for a mapping error sl4mip01 (445) : Test for known XPRESS bug, with solvelink=1,2,4,5 macro02 (446) : Multiline macro test put10 (447) : $on/offput inserted outside the loop set9 (448) : fast shifting of set elements




