Namespace: ILOG.Concert
Assembly: oplall (in oplall.dll)

Syntax

C#
public abstract class IColumnArray

Remarks

Objects of the class IColumnArray are used to create an array of variables using column-wise modeling. In column-wise modeling, newly constructed variables are inserted into existing modeling objects. The term column-wise comes from linear programing, where the constraints are typically represented as a matrix. Adding new variables to the optimization problem corresponds to adding columns to the constraint matrix.

This is the procedure for column-wise modeling:

Start with the set of modeling objects of these classes

  • IObjective,
  • IRange, and
  • ILPMatrix
to which you want to add new variables.

For each of these objects call IMPModeler.ColumnArray, with the object as a parameter, along with the other parameters needed to install an array of new variables in the existing modeling objects. See the ColumnArray()()()() documentation for details of these parameters.

The IColumnArray objects can then be linked to an aggregate IColumnArray object with the method IColumnArray.And, which will include all the individual objects. If the new variables are to be installed in only one modeling object, there is no need to use the method And.

The IColumnArray object constructed this way is now ready to be used to create an array of new variables and install them in the existing modeling objects, as described by the IColumnArray object. This is done by passing the IColumnArray object as a parameter to the constructor methods for arrays of variables, for example IMPModeler.NumVarArray or IMPModeler.IntVarArray. The newly created variables will immediately be part of the existing modeling objects that have been used for constructing the IColumnArray object.

The following example shows how to create an array of two new variables with the bounds 0 and 1 and how to install them in an objective and a range constraint, with linear coefficients all set to 1:

Examples

INumVar[] newColumns(IMPModeler modeler, IObjective obj, IRange rng) { double[] ones = {1.0, 1.0}; IColumnArray objcol = modeler.columnArray(obj, ones); IColumnArray rngcol = modeler.columnArray(rng, ones); return modeler.numVarArray(objcol.and(rngcol), 0.0, 1.0); }

Inheritance Hierarchy

System..::..Object
  ILOG.Concert..::..IColumnArray

See Also