DPOTRS(3)                  MathKeisan LAPACK routine                 DPOTRS(3)



NAME
       DPOTRS - a system of linear equations A*X = B with a symmetric positive
       definite matrix A using the Cholesky factorization A = U**T*U  or  A  =
       L*L**T computed by DPOTRF

SYNOPSIS
       SUBROUTINE DPOTRS( UPLO, N, NRHS, A, LDA, B, LDB, INFO )

           CHARACTER      UPLO

           INTEGER        INFO, LDA, LDB, N, NRHS

           DOUBLE         PRECISION A( LDA, * ), B( LDB, * )

PURPOSE
       DPOTRS  solves  a  system  of linear equations A*X = B with a symmetric
       positive definite matrix A using the Cholesky factorization A =  U**T*U
       or A = L*L**T computed by DPOTRF.


ARGUMENTS
       UPLO    (input) CHARACTER*1
               = 'U':  Upper triangle of A is stored;
               = 'L':  Lower triangle of A is stored.

       N       (input) INTEGER
               The order of the matrix A.  N >= 0.

       NRHS    (input) INTEGER
               The  number of right hand sides, i.e., the number of columns of
               the matrix B.  NRHS >= 0.

       A       (input) DOUBLE PRECISION array, dimension (LDA,N)
               The triangular factor U or L from the Cholesky factorization  A
               = U**T*U or A = L*L**T, as computed by DPOTRF.

       LDA     (input) INTEGER
               The leading dimension of the array A.  LDA >= max(1,N).

       B       (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
               On  entry, the right hand side matrix B.  On exit, the solution
               matrix X.

       LDB     (input) INTEGER
               The leading dimension of the array B.  LDB >= max(1,N).

       INFO    (output) INTEGER
               = 0:  successful exit
               < 0:  if INFO = -i, the i-th argument had an illegal value



 LAPACK routine (version 3.1)    November 2006                       DPOTRS(3)