Arguments of a ScaLAPACK routine appear in the following order:

- arguments specifying options,
- problem dimensions,
- array or scalar arguments defining the input data; some of them may be overwritten by results,
- other array or scalar arguments returning results,
- work arrays (and associated array dimensions), and
- diagnostic argument INFO.

Note that not every category is present in each of the routines.

When defining each of these categories
of arguments, ScaLAPACK distinguishes
between **local** and **global**
data. On entry to a ScaLAPACK routine,
**local input** arguments
may have different values on each
process in the process grid. Similarly,
**local output** arguments
may be assigned different values on
different processes in the process
grid on exit from the ScaLAPACK routine.

**Global input** arguments
must have the same value on each process in
the process grid on entry to a ScaLAPACK
routine. If this is not the case, most
routines will call `PXERBLA` and return.
**Global output**
arguments
are assigned the same value on all processes
in the process grid on exit from a ScaLAPACK
routine.

Tue May 13 09:21:01 EDT 1997