From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,cc6a4bc415a41111 X-Google-NewGroupId: yes X-Google-Attributes: gida07f3367d7,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Received: by 10.68.8.229 with SMTP id u5mr56755256pba.0.1317565147124; Sun, 02 Oct 2011 07:19:07 -0700 (PDT) Path: lh7ni9853pbb.0!nntp.google.com!news1.google.com!npeer02.iad.highwinds-media.com!news.highwinds-media.com!feed-me.highwinds-media.com!post02.iad.highwinds-media.com!news.flashnewsgroups.com-b7.4zTQh5tI3A!not-for-mail From: Stephen Leake Newsgroups: comp.lang.ada Subject: Re: fixed point vs floating point References: <440acd0c-f6ca-4c24-a8ae-3c5dbf71467c@dm9g2000vbb.googlegroups.com> <82lit6z64n.fsf@stephe-leake.org> Date: Sun, 02 Oct 2011 10:19:06 -0400 Message-ID: <82r52vwk6d.fsf@stephe-leake.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (windows-nt) Cancel-Lock: sha1:ya7Keu/emYi2I6aCvXXy0L3JdaI= MIME-Version: 1.0 X-Complaints-To: abuse@flashnewsgroups.com Organization: FlashNewsgroups.com X-Trace: e706c4e8872dae26b0fa606517 Xref: news1.google.com comp.lang.ada:18268 Content-Type: text/plain; charset=us-ascii Date: 2011-10-02T10:19:06-04:00 List-Id: "RasikaSrinivasan@gmail.com" writes: > in embedded platforms, it is not often we have a floating point > processor (or it may come at a price which we cannot afford!) and they > have to be emulated. fixed point arithmetic may do the job in certain > class of problems. in my class of problems, i am not sure the fixed > point arithmetic will be sufficient. the experiments are to understand > how the fixed point solutions may diverge from the floating point > solutions. It is not likely that experiment will answer that question, unless the only issue is speed. If you need to worry about data range and precision, analysis of the inputs and algorithms is necessary. It might be possible to develop a truly representative set of data for testing this, but that requires the same analysis! Speed has to be measured, on a representative set of data; it's somewhat easier to develop a data set that covers all speed issues. -- -- Stephe