DLAMCH(3)      LAPACK routine of NEC Numeric Library Collection      DLAMCH(3)



NAME
       DLAMCH - determine double precision machine parameters

SYNOPSIS
       DOUBLE PRECISION FUNCTION DLAMCH( CMACH )

           CHARACTER    CMACH

PURPOSE
       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)



LAPACK routine                  31 October 2017                      DLAMCH(3)