DLAMCH determines double precision machine parameters.

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)

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

 SLAMCH determines single precision machine parameters.

CMACH

          CMACH is CHARACTER*1


          Specifies the value to be returned by SLAMCH:


          = 'E' or 'e',   SLAMCH := eps


          = 'S' or 's ,   SLAMCH := sfmin


          = 'B' or 'b',   SLAMCH := base


          = 'P' or 'p',   SLAMCH := eps*base


          = 'N' or 'n',   SLAMCH := t


          = 'R' or 'r',   SLAMCH := rnd


          = 'M' or 'm',   SLAMCH := emin


          = 'U' or 'u',   SLAMCH := rmin


          = 'L' or 'l',   SLAMCH := emax


          = 'O' or 'o',   SLAMCH := 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)

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.