ILOG CPLEX 11.0 User's Manual

However, ILOG CPLEX updates the names so that each row or column index willcorrespond to the correct row or column name. Double checking names against indexnumbers is the only sure way to reveal which changes may have been made to matrix indicesin such a context. The routines CPXgetrowindex and CPXgetcolindex translate names toindices.Character StringsYou can pass character strings as parameters to various ILOG CPLEX routines, for example,as row or column names. The Interactive Optimizer truncates output strings 255 characters.Routines from the Callable Library truncate strings at 255 characters in output text files(such as MPS or LP text files) but not in binary SAV files. Routines from the CallableLibrary also truncate strings at 255 characters in names that occur in messages. Routines ofthe Callable Library that produce log files, such as the simplex iteration log file or the MIPnode log file, truncate at 16 characters. Input, such as names read from LP and MPS files ortyped interactively by the enter command, are truncated to 255 characters. However, it isnot recommended that you rely on this truncation because unexpected behavior may result.Checking Problem DataIf you inadvertently make an error entering problem data, the problem object will notcorrespond to your intentions. One possible result may be a segmentation fault or otherdisruption of your application. In other cases, ILOG CPLEX may solve a different modelfrom the one you intended, and that situation may or may not result in error messages fromILOG CPLEX.Using the Data Checking ParameterTo help you detect this kind of error, you can set the parameter CPX_PARAM_DATACHECK(int) to the value CPX_ON to activate additional checking of array arguments forCPXcopyData, CPXreadData, and CPXchgData routines (where Data varies). Theadditional checks include:◆◆◆◆◆◆invalid sense/ctype/sostype valuesindices out of range, for example, rowind ≥ numrowsduplicate entriesmatbeg or sosbeg array with decreasing valuesNANs in double arraysNULLs in name arraysThis additional checking may entail overhead (time and memory). When the parameter is setto CPX_OFF, only simple checks, for example checking for the existence of the environment,are performed.ILOG CPLEX 11.0 — USER’ S MANUAL 119