D1mach D1mach_sub Dlamch Dlamch_sub I1mach I1mach_sub R1mach R1mach_sub Slamch Slamch_sub

Dlamch_sub() Sub Dlamch_sub ( Ret As  Double, C As  String  ) Machine parameters (double precision floating-point arithmetic) (Subroutine version) Purpose Determines the machine parameters on double precision floating-point arithmetic. Parameters [out] Ret The value specified by C. (0 will be returned if C is invalid.) [in] C Specifies the value to be returned. = "E" or "e": Relative machine precision (eps) = "S" or "s": Safe minimum, such that 1/sfmin does not overflow = "B" or "b": Base of the machine (base) = "P" or "p": eps*base = "N" or "n": Number of (base) digits in the mantissa = "R" or "r": 1 when rounding occurs in addition, 0 otherwise = "M" or "m": Minimum exponent before (gradual) underflow = "U" or "u": Underflow threshold - base^(emin-1) = "L" or "l": Largest exponent before overflow = "O" or "o": Overflow threshold - (base^emax)*(1-eps) Reference LAPACK