The array descriptor **DESC_**
whose type is defined as
**DESC_(DTYPE_)=502** ,
is an integer array of length 7.
This descriptor type is used in
the ScaLAPACK narrow band routines
and tridiagonal routines to specify
the block-row distribution of a global
array containing the right-hand-side
vectors over a one-dimensional
process grid. In the narrow band
and tridiagonal routines, a
one-dimensional block-column
distribution is specified for
the coefficient matrix .
The matrix of right-hand-side
vectors however must be distributed
over a one-dimensional process grid
according to a block-row data
distribution scheme. Refer to
section 4.4.1 for
further details on block data
distribution.

Let us now assume that we have an
array descriptor *DESCB* for a
block-row distributed matrix *B*.
For readability of the code, we have
associated symbolic names with the
descriptor entries.

**Table 4.12:** Content of the array descriptor for right-hand-side dense
matrices for narrow band and tridiagonal solvers

For a detailed description of LOC() notation, please refer to section 4.4.2.

Tue May 13 09:21:01 EDT 1997