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## dlamch()

double precision function dlamch | ( | character | cmach | ) |

DLAMCH

Purpose:

      !>
      !> DLAMCH determines double precision machine parameters.
      !>

Parameters

  [in]

  CMACH

      !>          CMACH is CHARACTER*1
      !>          Specifies the value to be returned by DLAMCH:
      !>          = 'E' or 'e',   DLAMCH := eps
      !>          = 'S' or 's ,   DLAMCH := sfmin
      !>          = 'B' or 'b',   DLAMCH := base
      !>          = 'P' or 'p',   DLAMCH := eps*base
      !>          = 'N' or 'n',   DLAMCH := t
      !>          = 'R' or 'r',   DLAMCH := rnd
      !>          = 'M' or 'm',   DLAMCH := emin
      !>          = 'U' or 'u',   DLAMCH := rmin
      !>          = 'L' or 'l',   DLAMCH := emax
      !>          = 'O' or 'o',   DLAMCH := rmax
      !>          where
      !>          eps   = relative machine precision
      !>          sfmin = safe minimum, such that 1/sfmin does not overflow
      !>          base  = base of the machine
      !>          prec  = eps*base
      !>          t     = number of (base) digits in the mantissa
      !>          rnd   = 1.0 when rounding occurs in addition, 0.0 otherwise
      !>          emin  = minimum exponent before (gradual) underflow
      !>          rmin  = underflow threshold - base**(emin-1)
      !>          emax  = largest exponent before overflow
      !>          rmax  = overflow threshold  - (base**emax)*(1-eps)
      !>

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