From charlie at stat.umn.edu  Mon Jun 22 18:49:38 2009
From: charlie at stat.umn.edu (Charles Geyer)
Date: Mon, 22 Jun 2009 11:49:38 -0500
Subject: [Rd] Floating point precision / guard digits? (PR#13771)
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On Sat, 20 Jun 2009 08:44:21 -0400 Stavros Macrakis <macrakis at alum.mit.edu>
wrote:

> d) if it is important to your application to perform exact arithmetic
> on rational numbers (and I suspect it is not), you might want to use
> that instead of floating-point. But even if implemented in R, most R
> calculations cannot use it.

Just for the record, the contributed package rcdd links the GMP (GNU
multiprecision bignum) library and provides a crude interface, so it
is "implemented in R", although, as you say, "most R calculations cannot
use it".  The rcdd package can do exact linear programming and other
computational geometry operations.

-- 
Charles Geyer
Professor, School of Statistics
University of Minnesota
charlie at stat.umn.edu



[Rd] Floating point precision / guard digits? (PR#13771)
Charles Geyer