Contents

1 Contents1 Language Put file question .. How to transform a parameter .. Endogenous variable becomes exogenous .. Indexing a variable with subsets .. Using Subsets .. Using Aliases .. Sets in the LOOP construct .. Lag and lead circular .. Creating a subset to use as an index .. Index for the maximum value of a set .. Exception handling on indexes .. Introducing another dimension .. $ON/OFFEMPTY error .. What is the difference between the **-operator and the power function? .. Very large numbers .. Using the determinant .. Indexing connundrum .. How to transform a parameter.

2 Subsets and assignments .. Different variable types within one set .. Representing parameters as fixed variables .. Computing of cost components .. Divide by zero error in .. Interpretation of marginals .. GAMS-Solver Communication .. How is the basis information passed to the solver? .. Error: endogenous $operation not allowed .. Reporting solutions from numerous runs .. Generating a matrix using the loop statement .. Solves in a loop .. Looping GAMS, solving subsets of equations (periods) in a dynamic model .. Reducing the size of the listing file .. Reverse loops in GAMS .. Equations in Loop.

3 Put file question .. Slacks .. A sorted Table .. String manipulation in GAMS .. PUT-ing the element text of created subsets .. The gams225?-Subdirectories .. The gams225?-Subdirectories .. Calling GAMS from Fortran .. Batch-processing on PC .. Flexible $include-statements .. CPU time .. Precision problems .. Help with put facility .. Include statement with wild cards .. Counting the number of Equation for a specific constraint content -Type .. Loops and calling external programs from GAMS .. On bugs in ssimport .. How to get an equation listing without solving the model .. Functions.

4 The $abort statement .. Check for empty dynamic sets .. Using the screen as the put file .. Multiple solve .. Loops over subsets .. Summation Question .. Many to many mapping .. NLP with real-power constraint .. Parameter declaration .. Loop / recursive dynamic CGE .. Error message .. Spot an error .. Endogeneous relational operations .. Suppressing the output listing .. Stopping the iteration process .. 672 Solver related General Questions .. Changing Solvers .. Using different option files .. Solution of infeasible subproblems .. Scaling Strategies .. Strategies for Restarting models.

5 Funny results from the simplex methods .. Infeasibility .. MIP-solver .. Special Ordered Sets .. Marginal Values in MIP-Poblems .. What is the default upper bound for an integer variable? .. Non integer results in a integer model .. Error message from GAMS/ZOOM: Node table is full .. A query about CPLEX .. General NLP solver .. Model becomes infeasible after removing constraints .. Error: ** A derivative is too large (larger than +05) .. EXIT - THE CURRENT POINT CANNOT BE IMPROVED UPON .. EXIT NUMERICAL ERROR. GENERAL CONSTRAINTS CANNOT BE SATIS-FIED ACCURATELY .. CONOPT: Fatal Error: Insufficient Memory.

6 MINOS: TOO MANY ITERATIONS .. CONOPT: Default accuracy .. MINOS: ITERLIMIT .. Problem with solving a quadratic program .. MCP solver .. Problems with the MILES Solver .. CUMULATIVEPIVOTLIMITEXCEEDED .. Iteration limit .. MILES vs. PATH .. Matrix balancing with PATH .. Queries about the PATH solver (using GAMS ) .. PATH and convergence .. Memory problems in PATH .. Solutions in Miles .. MINLP solver .. When to switch from a NLP to a MINLP-formulation .. Problems switching from NLP to MINLP .. MINLP output .. 1073 General Modeling Examples and An IP formulation question - modeling logical constraints.

7 Nonlinear model solution problems .. DEA example model .. Different solutions with different GAMS versions .. Scaling the Hessian .. Fixed variables vs. params vs. equations ? .. Solving a system of non-linear equations .. GAMS code for GAMMA sampling .. Obtaining the Hessian .. Modeling absolute Values .. Writing to Files Named by Set Text Labels .. Help with linearizing function .. How do I model either or or conditional constraints? .. A Team Scheduling problem .. RASing a matrix .. Chip Design Problem .. Obtaining Eigenvalues .. Stochastic optimization - an example .. Data aggregation with GAMS.

8 A TSP Gams Code .. A Jacobian construction Problem .. Formulating a piece wise linear function .. A PSD-Problem .. Time optimal dynamic optimization by GAMS .. Modelling convergence .. Integration .. Help .. Availability of livestock models in developing countries .. Integer constraint .. Delayed Response Models .. Illustration of how to estimate and then simulate .. Sensitivity analysis .. Problems with regression model .. Calculation of initial values for NLP models .. Endogenous variable becomes exogenous .. Cholesky Decomposition .. 187 CONTENTS14 Modeling Examples and Tricks for Using set in endogenous tax field.

9 An overlapping generations example model .. Another overlapping generations example model .. A spatial equilibrium model with continuous piece-wise linear cost functions with discontinuousderivatives .. Changes in the I-O Matrix .. Marginal and average taxes in MPSGE .. GE modeling with transport emissions .. A Primer in dynamic GE modeling .. Building Applied General Equilibrium Models in GAMS. A users guide and a library of Negative Inventories in MPSGE .. CGE with Integer Number .. Perfect elasticity in CGE .. Balancing SAM .. CES function in MPSGE syntax .. MPSGE question .. Congestion model .. Income transfers and negative savings in CGE-models.

10 SAM vs. CGE Models .. Help needed: differential tax policy analysis .. MPSGE .. Welfare measures .. Recursive dynamic modeling using MPSGE .. Papers on pension system reforms .. Implementing a quota in MPSGE .. 2512 CONTENTSC hapter 1 Language Put file questionSuppose I have a model that I want to run t = 1 .. T times, where on each model run a price increases by afixed increment. Further suppose there are 2 output files that have data sent to them via a put statement and for each. I want to set up a looping procedure where my model is within the loop andmy price increases by a fixed constant within each loop. Is there any syntax that would allow me to includethe value of,t, in the name of output files.