From: bakul at bitblocks.com (Bakul Shah)
Subject: [COFF] floating point (Re: Old and Tradition was [TUHS] V9 shell
Date: Wed, 12 Feb 2020 15:54:32 -0800 [thread overview]
Message-ID: <96B92BC1-F4AF-448E-8453-E77C27E7B545@bitblocks.com> (raw)
In-Reply-To: <20200212230542.GR852@mcvoy.com>
On Feb 12, 2020, at 3:05 PM, Larry McVoy <lm at mcvoy.com> wrote:
>
> On Wed, Feb 12, 2020 at 04:45:54PM -0600, Charles H Sauer wrote:
>> If I recall correctly:
>> - all doctoral candidates ended up taking two semesters of numerical
>> analysis. I still have two volume n.a. text in the attic (orange, but not
>> "burnt orange", IIRC).
>> - numerical analysis was covered on the doctoral qualifying exam.
>
> Pretty sure Madison required that stuff for Masters degrees. Or maybe
> undergrad, I feel like I took that stuff pretty early on.
>
> I'm very systems oriented so I can't imagine I would have taking that
> willingly. I hate the whole idea of floating point, just seems so
> error prone.
David Goldberg's article "What every computer scientist should know
about floating-point arithmetic" is a good one to read:
https://www.itu.dk/~sestoft/bachelor/IEEE754_article.pdf
I still have Bill Press's Numerical Recipes book though not opened
recently (as in not since '80s)!
It is interesting that older languages such as Lisp & APL have a
builtin concept of tolerance. Here 0.3 < 0.1 + 0.2 is false. But
in most modern languages it is true! This is so since 0.1 + 0.2 is
0.30000000000000004. In Fortran you'd write something like
abs(0.3 - (0.1 + 0.2)) > tolerance. You can do the same in C
etc.but for some reason it seems to be uncommon :-)
next prev parent reply other threads:[~2020-02-12 23:54 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-11 18:41 [COFF] " clemc
[not found] ` <CAP2nic2C4-m_Epcx7rbW2ssbS850ZFiLKiL+hg1Wxbcwoaa1vQ@mail.gmail.com>
2020-02-12 0:57 ` [COFF] Fwd: " athornton
2020-02-12 1:58 ` clemc
2020-02-12 3:01 ` lm
2020-02-12 18:12 ` clemc
2020-02-12 21:55 ` cym224
2020-02-12 22:11 ` imp
2020-02-12 22:45 ` sauer
2020-02-12 23:05 ` lm
2020-02-12 23:54 ` bakul [this message]
2020-02-12 23:56 ` [COFF] floating point (Re: " bakul
2020-02-13 1:21 ` toby
2020-02-13 6:57 ` [COFF] Fwd: " peter
2020-02-16 21:47 ` wobblygong
2020-02-16 22:10 ` clemc
2020-02-16 22:45 ` krewat
2020-02-16 23:50 ` bakul
2020-02-18 0:17 ` dave
2020-02-18 12:48 ` jpl.jpl
2020-02-24 9:40 ` ik
2020-02-24 15:19 ` lm
[not found] ` <CAP2nic0fK+=eh=5MuY4BJH6zx4tCRMWcazmm1khYMzNmEdf8ug@mail.gmail.com>
2020-02-24 16:15 ` [COFF] [TUHS] Fwd: Old and Tradition was " clemc
2020-02-24 16:19 ` clemc
2020-02-24 16:27 ` [COFF] Fwd: Old and Tradition was [TUHS] " clemc
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=96B92BC1-F4AF-448E-8453-E77C27E7B545@bitblocks.com \
--to=coff@minnie.tuhs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).