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problem.chgBounds

Purpose
Used to change the bounds on columns in the matrix.
Topic area
Problem Modification
Synopsis
problem.chgBounds(colind, bndtype, bndval)
Arguments
colind 
Integer array containing the indices of the columns on which the bounds will change.
bndtype 
Character array indicating the type of bound to change:
U 
indicates change the upper bound;
L 
indicates change the lower bound;
B 
indicates change both bounds, i.e. fix the column.
bndval 
Double array giving the new bound values.
Further information
1. A column index may appear twice in the colind array so it is possible to change both the upper and lower bounds on a variable in one go.
2. problem.chgBounds can be used from within callbacks to modify the local node bounds of a branch-and-bound search. In this case, the solver expects column indices to match the presolved problem. This function can be called from within the following callbacks: problem.addPrenodeCallback, problem.addNodeLPSolvedCallback, problem.addOptnodeCallback.
3. The double constants xpress.infinity and -xpress.infinity defined in the library header file can be used to represent plus and minus infinity respectively in the bound ( bndval) array.
4. If the upper bound on a binary variable is changed to be greater than 1 or the lower bound is changed to be less than 0 then the variable will become an integer variable.
5. Argument colind may contain xpress.var objects instead of indices.
Related topics
problem.getLB, problem.getUB,

Parent Topic Methods of the class problem

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