The Simplex Log

During the simplex optimization, a summary log is displayed every n iterations, where n is the value of LPLOG. This summary log has the form:


Its	The number of iterations or steps taken so far.
Obj Value	The objective function value.
S	The current solution method (p primal; d dual).
Ninf	The number of infeasibilities.
Nneg	The number of variables which may improve the current solution if assigned a value away from their current bounds.
Sum inf	The scaled sum of infeasibilities. For the dual algorithm this is the scaled sum of dual infeasibilities when the number of negative dj's is non-zero.
Time	The number of seconds spent iterating.

A more detailed log can be displayed every n iterations by setting LPLOG to -n. The detailed log has the form:


Its	The number of iterations or steps taken so far.
S	The current solution method (p primal; d dual).
Ninf	The number of infeasibilities.
Obj Value	If the solution is infeasible, the scaled sum of infeasibilities, otherwise: the objective value.
In	The sequence number of the variable entering the basis (negative if from upper bound).
Out	The sequence number of the variable leaving the basis (negative if to upper bound).
Nneg	The number of variables which may prove the current solution if assigned a value away from their current bounds.
Dj	The scaled rate at which the most promising variable would improve the solution if assigned a value away from its current bound (reduced cost).
Neta	A measure of the size of the inverse.
Nelem	Another measure of the size of the inverse.
Time	The number of seconds spent iterating.

If LPLOG is set to 0, no log is displayed until the optimization finishes.