Arguments specifying
options are usually of type CHARACTER1.
The arguments that specify options are character
arguments with the names `SIDE`, `TRANS`,
`UPLO`, and `DIAG`. On entry to a ScaLAPACK
routine, these arguments are **global input**
and must have the same value on each process in
the process grid.

`SIDE` is used by the
routines as follows:

`TRANS` is used by
the routines as follows:

In the real case the values ``T'` and ``C'`
have the same meaning, and in the complex case the
value ``T'` is not allowed.

`UPLO` is used by
the Hermitian, symmetric, and triangular
distributed matrix routines to specify
whether the upper or lower triangle is
being referenced as follows:

`DIAG` is used by
the triangular distributed matrix routines
to specify whether the distributed matrix
is unit triangular, as follows:

When `DIAG` is supplied as ``U'`,
the diagonal elements are not referenced.
For example:

- UPLO
- (global input) CHARACTER1

= 'U': Upper triangle of the matrix A(IA:IA+M-1,JA:JA+N-1);

= 'L': Lower triangle of the matrix A(IA:IA+M-1,JA:JA+N-1).

The corresponding lower-case characters may be supplied (with the same meaning), but any other value is illegal (see section 4.6.6).

A longer character string can be passed as the actual argument, making the calling program more readable, but only the first character is significant; this is a standard feature of Fortran 77. For example:

CALL PSPOTRS('upper', . . . )

Tue May 13 09:21:01 EDT 1997