BLACS(3)                       MathKeisan BLACS                       BLACS(3)



NAME
       Basic Linear Algebra Communication Subprograms  (BLACS)

DESCRIPTION
       BLACS  (Basic  Linear Algebra Communication Subprograms) are a message-
       passing library designed for linear algebra.  The  computational  model
       consists  of a one- or two-dimensional process grid, where each process
       stores pieces of the matrices  and  vectors.  The  BLACS  include  syn-
       chronous  send/receive  routines  to  communicate a matrix or submatrix
       from one process to another, to  broadcast  submatrices  to  many  pro-
       cesses, or to compute global data reductions (sums, maxima and minima).
       There are also routines to construct,  change,  or  query  the  process
       grid.  Since  several ScaLAPACK algorithms require broadcasts or reduc-
       tions among different subsets of processes, the BLACS permit a  process
       to  be  a member of several overlapping or disjoint process grids, each
       one labeled by a context. In MPI this is  called  a  communicator.  The
       BLACS  provide  facilities  for safe inter-operation of system contexts
       and BLACS contexts.

       The BLACS in MathKeisan is based on the University of Tennessee  imple-
       mentation  for  MPI  platform, written by Jack J. Dongarra and R. Clint
       Whaley.  More information on BLACS, including a users guide  is  avail-
       able at:

              http://www.netlib.org/blacs/

       If you have any problems with this library, please contact us at:

              http://www.mathkeisan.com/

SEE ALSO
       mathkeisan(3), MathKeisan User's Guide at:

              http://www.mathkeisan.com/

       The command:

              man mathkeisan

       gives more information on linking.



BLACS                                                                 BLACS(3)