# dptsl.f

          SUBROUTINE DPTSL (N, D, E, B)
    C***BEGIN PROLOGUE  DPTSL
    C***PURPOSE  Solve a positive definite tridiagonal linear system.
    C***LIBRARY   SLATEC (LINPACK)
    C***CATEGORY  D2B2A
    C***TYPE      DOUBLE PRECISION (SPTSL-S, DPTSL-D, CPTSL-C)
    C***KEYWORDS  LINEAR ALGEBRA, LINPACK, MATRIX, POSITIVE DEFINITE, SOLVE,
    C             TRIDIAGONAL
    C***AUTHOR  Dongarra, J., (ANL)
    C***DESCRIPTION
    C
    C     DPTSL, given a positive definite symmetric tridiagonal matrix and
    C     a right hand side, will find the solution.
    C
    C     On Entry
    C
    C        N        INTEGER
    C                 is the order of the tridiagonal matrix.
    C
    C        D        DOUBLE PRECISION(N)
    C                 is the diagonal of the tridiagonal matrix.
    C                 On output D is destroyed.
    C
    C        E        DOUBLE PRECISION(N)
    C                 is the offdiagonal of the tridiagonal matrix.
    C                 E(1) through E(N-1) should contain the
    C                 offdiagonal.
    C
    C        B        DOUBLE PRECISION(N)
    C                 is the right hand side vector.
    C
    C     On Return
    C
    C        B        contains the solution.
    C
    C***REFERENCES  J. J. Dongarra, J. R. Bunch, C. B. Moler, and G. W.
    C                 Stewart, LINPACK Users' Guide, SIAM, 1979.
    C***ROUTINES CALLED  (NONE)
    C***REVISION HISTORY  (YYMMDD)
    C   780814  DATE WRITTEN
    C   890505  REVISION DATE from Version 3.2
    C   891214  Prologue converted to Version 4.0 format.  (BAB)
    C   900326  Removed duplicate information from DESCRIPTION section.
    C           (WRB)
    C   920501  Reformatted the REFERENCES section.  (WRB)
    C***END PROLOGUE  DPTSL