CXML
        	    
LAPACK version 3.0
dlamch(3)

PURPOSE
  DLAMCH - determine double precision machine parameters

SYNTAX
  DOUBLE PRECISION FUNCTION DLAMCH( CMACH )

      CHARACTER	   CMACH

DESCRIPTION
  DLAMCH determines double precision machine parameters.

ARGUMENTS
  CMACH	  (input) 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)