Documentation


GRBBinvColj

int GRBBinvColj ( GRBmodel *model,
    int j,
    GRBsvec *x )

Computes the solution to the linear system <span>$</span>Bx=A_j<span>$</span>, where <span>$</span>B<span>$</span> is the current simplex basis matrix and <span>$</span>A_j<span>$</span> is the column of the constraint matrix <span>$</span>A<span>$</span> associated with variable <span>$</span>j<span>$</span>.

Return value:

A non-zero return value indicates that a problem occurred while computing the desired vector. 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.

j: Indicates the index of the column of <span>$</span>A<span>$</span> to use as the right-hand side for the linear solve. The index j must be between 0 and cols-1, where cols is the number of columns in the model.

x: The sparse result vector. The user is responsible for allocating the ind and val fields to be large enough to hold as many as one non-zero entry per constraint in the model.