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CONVERT developed by GAMS Corporation transforms a GAMS model instance into a format used by other modeling and solutions systems. CONVERT is designed to achieve three aims:
| • | Permit users of GAMS to convert a confidential model into a GAMS solvable scalar form with very little identifying its structure so it can be given to a group for numerical investigation (i.e to have someone else help with a solution problem while maintaining confidentiality). |
| • | Give a path to solving with other solvers that may not be available in GAMS to test performance. |
| • | Give a way of sharing test problems. |
Currently, CONVERT can translate GAMS models into a AlphaECP, AMPL, AmplNLC, BARON, CoinFML, CplexLP, CplexMPS, Dict, FixedMPS, GAMS Scalar format, LAGO, LGO, LindoMPI, LINGO, MINOPT, NLP2MCP or ViennaDag type of problem. In addition Jacobian creates a GDX file containing the basic model data (matrix, initial point, evaluation of constraints at initial point and bounds).
The translator creates a "scalar model" which consists of
| • | A model without sets or indexed parameters in the scalar models, that is one that does not exploit the more advanced characteristics of any modeling system and is easily transformable. |
| • | A model with a new set of individual variables depicting each variable in the GAMS model ending up with potentially 3 variable classes for the positive, integer, and binary variables each numbered sequentially (i.e. all positive GAMS variables are mapped into n single variables X1 - Xn thus if we have transport(i,j) and manufacture(k) we would have a set of unindexed scalar variables X1, X2, ... with i*j+k cases.), |
| • | A model with individual equations depicting each variable in the GAMS model (ie all GAMS equations are mapped into m constraints E1, E2, ... Em thus if we have demand(j) and resources(r,k) we would have a new equations E1, E2,... with j+r*k cases), |
| • | The symbolic form of these equations. |
| • | Bounds or starting point values. |
Models of the types LP, MIP, RMIP, NLP, MCP, MPEC, CNS, DNLP, RMINLP and MINLP can be converted. Convert.pdf contains the program writeup.
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