$title Option solveOpt explained (SOLVEOPT,SEQ=347)

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The option SOLVEOPT controls the way solution values are returned to the
GAMS internal data base. There are two ways to enter solveopt values:

 1. For all solves following: option solveOpt = merge|replace|clear

    merge  : solution values are merged into the existing GAMS data base.
             This is the DEFAULT behavior.
    replace: all equation in the model list and all variable appearing in the
             final model instance, are removed before solution records are
             returned to the GAMS data base.
    clear  : all equations and all variables mentioned in symbolic equations
             belonging to the current model instance are removed before
             solution records are returned to the GAMS data base.
 2. For a specific model: <model>.solveOpt = n

    1  merge    this is the DEFAULT value
    0  replace
    2  clear

    The model attribute is initialized to NA, which means to use the global
    solveopt settings.

GAMS Development Corporation, Modeling Tool Box.

Keywords: linear programming, GAMS language features, solveOpt option
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Set
   i    / a, b, c /
   j(i) /    b    /;

Variable obj, x1(i), x2(i), x3(i), x4(i);

Equation defobj, e1(i), e2(i), e3(i);

defobj..   obj   =e= sum(i, x1(i));

e1(i)..    x1(i) =g= ord(i) + x4(i)$0;

e2(j)..    x2(j) =e= 20;

e3(i)$0 .. x3(i) =e= ord(i)*10;

Model m / all /;

m.limCol = 0;
m.limRow = 0;

x1.up(i) = 10;
x2.up(i) = 20;
x3.up(i) = 30;
x4.up(i) = 40;

e1.scale(i) = 10;
e2.scale(i) = 20;
e3.scale(i) = 30;

* option solveopt = merge;
m.solveOpt = 1;
solve m using lp min obj;

* data items not in the model instance remain unchanged
display x1.up, x2.up, x3.up, x4.up, e1.scale, e2.scale, e3.scale;

* option solveopt = replace;
m.solveOpt = 0;
solve m using lp min obj;

* data of equations in the model list will be removed before results are returned
* data of variables in the current model instance will be removed before
* returning results
display x1.up, x2.up, x3.up, x4.up, e1.scale, e2.scale, e3.scale;

* option solveopt = clear;
m.solveOpt = 2;
solve m using lp min obj;

* data of equations in the model list will be removed before results are returned
* data of variables appearing in the symbolic equations of model will be
* removed before results are returned
display x1.up, x2.up, x3.up, x4.up, e1.scale, e2.scale, e3.scale;