DPBTRS - solve a system of linear equations A*X = B with a
       symmetric  positive  definite  band  matrix  A  using  the
       Cholesky  factorization  A = U**T*U or A = L*L**T computed
       by DPBTRF


SYNOPSIS

       SUBROUTINE DPBTRS( UPLO, N, KD, NRHS, AB,  LDAB,  B,  LDB,
                          INFO )

           CHARACTER      UPLO

           INTEGER        INFO, KD, LDAB, LDB, N, NRHS

           DOUBLE         PRECISION AB( LDAB, * ), B( LDB, * )


PURPOSE

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


ARGUMENTS

       UPLO    (input) CHARACTER*1
               = 'U':  Upper triangular factor stored in AB;
               = 'L':  Lower triangular factor stored in AB.

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

       KD      (input) INTEGER
               The number of superdiagonals of the  matrix  A  if
               UPLO  = 'U', or the number of subdiagonals if UPLO
               = 'L'.  KD >= 0.

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

       AB      (input) DOUBLE PRECISION array, dimension (LDAB,N)
               The triangular factor U or  L  from  the  Cholesky
               factorization A = U**T*U or A = L*L**T of the band
               matrix A, stored in the first  KD+1  rows  of  the
               array.  The j-th column of U or L is stored in the
               j-th column of the array AB as  follows:  if  UPLO
               ='U',   AB(kd+1+i-j,j)   =   U(i,j)  for  max(1,j-
               kd)<=i<=j; if UPLO ='L', AB(1+i-j,j)     =  L(i,j)
               for j<=i<=min(n,j+kd).

       LDAB    (input) INTEGER
               The  leading  dimension  of the array AB.  LDAB >=
               KD+1.

               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 ille­
               gal value


Man(1) output converted with man2html