Procedure GMP::Column::FreezeRaw(GMP, colSet, value)


The procedure GMP::Column::FreezeRaw freezes a group of columns in a generated mathematical program.

     GMP,            ! (input) a generated mathematical program
     colSet,         ! (input) a subset of Integers
     value           ! (input) a parameter



An element in AllGeneratedMathematicalPrograms.


A subset of the set Integers, representing a set of column numbers.


A parameter over colSet, defining the value for each column to which it should be frozen.

Return Value

The procedure returns 1 on success, and 0 otherwise.


  • The columns remain visible in the constraint listing and math program inspector. In addition, it will be retained in solver maintained copies of the generated math program.

  • Use GMP::Column::UnfreezeRaw to undo the freezing.

  • During a call to procedure GMP::Column::FreezeRaw AIMMS stores the upper and lower bound of the columns before the procedure was called. This information is used when procedure GMP::Column::UnfreezeRaw is called thereafter. This information is not copied by the function GMP::Instance::Copy.


Assume that ‘MP’ is a mathematical program. To use GMP::Column::FreezeRaw we declare the following identifiers (in ams format):

ElementParameter myGMP {
    Range: AllGeneratedMathematicalPrograms;
Set VariableSet {
    SubsetOf: AllVariables;
Set ColumnSet {
    SubsetOf: Integers;
    Index: cc;
Parameter FixVal {
    IndexDomain: cc;

To freeze the variable x(i) we can use:

myGMP := GMP::Instance::Generate( MP );

VariableSet := { 'x' };
ColumnSet := GMP::Instance::GetColumnNumbers( myGMP, VariableSet );

FixVal(cc) := 20.0;

GMP::Column::FreezeRaw( myGMP, ColumnSet, FixVal );