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From: ken@turtlevax.UUCP (Ken Turkowski)
Newsgroups: net.lang.c,net.math
Subject: Re:  C Floating point arithmetic
Message-ID: <983@turtlevax.UUCP>
Date: Tue, 3-Dec-85 18:55:10 EST
Article-I.D.: turtleva.983
Posted: Tue Dec  3 18:55:10 1985
Date-Received: Fri, 6-Dec-85 07:28:41 EST
References: <123@brl-tgr.ARPA> <1078@lll-crg.ARpA> <336@bdaemon.UUCP>
Reply-To: ken@turtlevax.UUCP (Ken Turkowski)
Organization: CIMLINC, Inc. @ Menlo Park, CA
Lines: 22
Keywords: double-double!
Xref: watmath net.lang.c:7300 net.math:2598
Summary: What do you do when double precision isn't enough?

>> Any intelligent scientific programmer trys it both ways
>> on his own and determines whether single precision is adequate
>> (without the help of a numerical analyst, an analyst is consulted
>> when one wants to understand the root of the problem in an attempt
>> to rearrange the computation so that single precision is sufficient
>> should it fail).  .... more stuff, largely irrelevant .....

And suppose that the numerical analyst says that double precision
isn't enough precision regardless of the ordering of the computation;
what do you do then?

Check out:

Linnainmaa, Seppo
"Software for Doubled-Precision Floating-Point Computations",
ACM Transactions on Mathematical Software,
Vol. 7, No. 3, Sept 1981, pp. 272-283

-- 
Ken Turkowski @ CIMLINC, Menlo Park, CA
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