Re: Machine epsilon

Here is even a simpler way for macheps for Dr. Elbert
 ---------- Begin Forwarded Message ----------
 > From elbert-0at0-tc1.chem.iastate.edu Tue Jun 25 12:38:19 1991
 > Date: Tue, 25 Jun 91 11:40:12 CDT
 > From: elbert-0at0-tc1.chem.iastate.edu (Stephen T. Elbert)
 > To: jkl-0at0-ccl.net
 > Subject: Machine epsilon
 A much simpler, faster way of computing eps is
         a = 4.d0/3.d0
   10    b = a - 1.0d0
         c = b + b + b
         eps = abs(c - 1.0d0)
         if (eps .eq. 0.0d0) go to 10
 This code has been used by EISPACK for years.  The branch is to keep the
 compiler from using possibly incorrect register values.
 Stephen Elbert               Iowa State University    515-294-1307 voice mail
                              Ames Laboratory - USDOE  515-294-3226 FAX
 elbert-0at0-IaState.edU           315a Wilhelm Hall
 elbert-0at0-alisuvax.bitnet       Ames, IA 50011
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