ILOG CPLEX 11.0 User's Manual

indices, errors will occur. Therefore, in parts of your application that delete portions of theproblem, look carefully at how dimensions and indices are represented.Make Local Variables Temporarily GlobalIf you are having difficulty tracking down the source of an anomaly in the heap, try makingcertain local variables temporarily global. This debugging trick may prove useful after yourapplication reads in a problem file or modifies a problem object. If application behaviorchanges when you change a local variable to global, then you may get from it a better idea ofthe source of the anomaly.Solve the Problem You IntendedYour application may inadvertently alter the problem and thus produce unexpected results.To check whether your application is solving the problem you intended, use the InteractiveOptimizer, as in Using the Interactive Optimizer for Debugging on page 138, and thediagnostic routines, as in Using Diagnostic Routines for Debugging on page 120.You should not ignore any ILOG CPLEX warning message in this situation either, so readyour messages, as in Read Your Messages on page 141.If you are working in the Interactive Optimizer, you can use the commanddisplay problem stats to check the problem dimensions.Special Considerations for FortranCheck row and column indices. Fortran conventionally numbers from one (1), whereas Cand C++ number from zero (0). This difference in numbering conventions can lead tounexpected results with regard to row and column indices when your application modifies aproblem or exercises query routines.It is important that you use the Fortran declaration IMPLICIT NONE to help you detect anyunintended type conversions, because such inadvertent conversions frequently lead tostrange application behavior.Tell UsFinally, if your problem remains unsolved by ILOG CPLEX, or if you believe you havediscovered a bug in ILOG CPLEX, ILOG would appreciate hearing from you about it.142 ILOG CPLEX 11.0 — USER’ S MANUAL