Computes the solution to the linear system , where is the transpose of the current simplex basis matrix, is an input vector, and is the result vector.
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.
model: The model. Note that the model must have a current optimal basis, as computed by GRBoptimize.
b: The sparse right-hand side vector. It should contain one entry for each non-zero value in the input.
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.