Documentation

GRBgetBasisHead


GRBgetBasisHead

int GRBgetBasisHead ( GRBmodel *model,
    int *bhead )

Returns the indices of the variables that make up the current basis matrix.

Return value:

A non-zero return value indicates that a problem occurred while extracting the basis. Refer to the Error Code table for a list of possible return values. Details on the error can be obtained by calling GRBgeterrormsg.

Arguments:

model: The model. Note that the model must have a current optimal basis, as computed by GRBoptimize.

bhead: The constraint matrix columns that make up the current basis. The result contains one entry per constraint in $A$. If bhead[i]=j, then column i in the basis matrix $B$ is column j from the constraint matrix $A$. Note that the basis may contain slack or articifial variables. If bhead[i] is greater than or equal to cols (the number of columns in $A$), then the corresponding basis column is the articial or slack variable from row bhead[i]-cols.