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## cpbtrs()

subroutine cpbtrs | ( | character | uplo,
|  | integer | n,
|  | integer | kd,
|  | integer | nrhs,
|  | complex, dimension( ldab, * ) | ab,
|  | integer | ldab,
|  | complex, dimension( ldb, * ) | b,
|  | integer | ldb,
|  | integer | info )

CPBTRS

Download CPBTRS + dependencies [TGZ] [ZIP] [TXT]

Purpose:

      !>
      !> CPBTRS solves a system of linear equations A*X = B with a Hermitian
      !> positive definite band matrix A using the Cholesky factorization
      !> A = U**H*U or A = L*L**H computed by CPBTRF.
      !>

Parameters

  [in]

  UPLO

      !>          UPLO is CHARACTER*1
      !>          = 'U':  Upper triangular factor stored in AB;
      !>          = 'L':  Lower triangular factor stored in AB.
      !>

  [in]

  N

      !>          N is INTEGER
      !>          The order of the matrix A.  N >= 0.
      !>

  [in]

  KD

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

  [in]

  NRHS

      !>          NRHS is INTEGER
      !>          The number of right hand sides, i.e., the number of columns
      !>          of the matrix B.  NRHS >= 0.
      !>

  [in]

  AB

      !>          AB is COMPLEX array, dimension (LDAB,N)
      !>          The triangular factor U or L from the Cholesky factorization
      !>          A = U**H*U or A = L*L**H 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).
      !>

  [in]

  LDAB

      !>          LDAB is INTEGER
      !>          The leading dimension of the array AB.  LDAB >= KD+1.
      !>

  [in,out]

  B

      !>          B is COMPLEX array, dimension (LDB,NRHS)
      !>          On entry, the right hand side matrix B.
      !>          On exit, the solution matrix X.
      !>

  [in]

  LDB

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

  [out]

  INFO

      !>          INFO is INTEGER
      !>          = 0:  successful exit
      !>          < 0:  if INFO = -i, the i-th argument had an illegal value
      !>

Author
  Univ. of Tennessee
  Univ. of California Berkeley
  Univ. of Colorado Denver
  NAG Ltd.