DLAMCH
Based on LAPACK DLAMCH but with Fortran 95 query functions
See: http://www.cs.utk.edu/~luszczek/lapack/lamch.html
and http://www.netlib.org/lapack-dev/lapack-coding/program-style.html#id2537289
July 2010
See: http://www.cs.utk.edu/~luszczek/lapack/lamch.html
and http://www.netlib.org/lapack-dev/lapack-coding/program-style.html#id2537289
July 2010
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) |