VEC_ Error Handling

The error handling strategy used by the VEC_ routines is as follows:

1. If the STATUS argument is not set to SAI__OK on entry, then the routine returns immediately without action -- the contents of the RESULT array remain undefined in this case.

2. If the BAD argument is set to .TRUE. and any element of an input argument array is bad, then a bad value is placed in the corresponding element of the RESULT array.

3. A bad value is also placed in the corresponding element of the RESULT array if a numerical error occurs when processing any element of an input argument array -- in this instance an appropriate error code will also be returned via the STATUS argument.

On exit, the IERR argument will contain the index of the first array element which generated a numerical error (or zero if there were no errors) and NERR will contain a count of the number of numerical errors which occurred. If more than one error occurred, then the STATUS value returned will be appropriate to the first of these.