9. TAO Initialization

All TAO programs contain a call to

   info = TaoInitialize(int *argc,char ***argv,char *file_name,  
                        char *help_message); 
This command initializes TAO (and also MPI and PETSc if these have not yet been initialized elsewhere). The arguments argc and argv are the command line arguments delivered in all C and C++ programs. The argument file_name optionally indicates an alternative name for an options file, which by default is called .petscrc and resides in the user's home directory. See the PETSc users manual for details regarding runtime option specification. The final argument, help_message, is an optional character string that will be printed if the program is run with the -help option.

As illustrated by the TaoInitialize() statement above, TAO routines return an integer indicating whether an error has occurred during the call. The error code is set to be nonzero if an error has been detected; otherwise, it is zero. For the C or C++ interface, the error variable is the routine's return value, while for the Fortran version, each TAO routine has as its final argument an integer error variable. Error tracebacks are discussed in Section .