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Groups > comp.lang.java.programmer > #6883
| From | Jan Burse <janburse@fastmail.fm> |
|---|---|
| Newsgroups | comp.lang.java.programmer |
| Subject | Re: higher precision doubles |
| Date | 2011-08-09 01:08 +0200 |
| Organization | albasani.net |
| Message-ID | <j1pq9c$6d0$1@news.albasani.net> (permalink) |
| References | (11 earlier) <nOednS4yGv5WIaPTnZ2dnUVZ_gqdnZ2d@earthlink.com> <j1momo$34q$1@news.albasani.net> <j1nbr7$h7r$1@dont-email.me> <j1o1sk$427$1@news.albasani.net> <j1pif0$lr4$1@news.albasani.net> |
BGB schrieb:
> division is mostly calculating the reciprocal of the second value, and
> multiplying the first by this (can be done using Newton's Method).
I don't know exactly what you understand by
this algorithm. But if I understand this as
calculating the reciprocal first adn then
multiplying, you will have as a result:
o(x*o(1/y))
Instead of
o(x/y).
you will usually get less accurate results
since by the reciprocal-math option method
two approximations will be involved.
This is just a guess from the hip. But here
you see a simple excel verifying the claim:
1 2 3 4 5 6 7 8
1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5 0.00 0.00 0.00 0.00 0.00 -0.01 -0.01 0.00
6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
8 0.00 0.00 0.01 0.00 0.00 -0.01 0.00 0.00
Used formula:
=ROUND($G6/H$5;2)-ROUND($G6*ROUND(1/H$5;3);2)
1 2 3 4 5 6 7 8
1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
3 0.00 0.00 0.01 0.00 0.00 0.01 0.00 0.00
4 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00
5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
6 0.00 0.00 0.01 0.00 0.00 0.01 0.00 0.00
7 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00
8 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.00
Used formula:
=FLOOR($G6/H$5;2)-FLOOR($G6*FLOOR(1/H$5;3);2)
Errors are also seen for larger numbers of digits.
Bye
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higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-06 00:20 +0200
Re: higher precision doubles Patricia Shanahan <pats@acm.org> - 2011-08-06 03:35 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-06 13:03 +0200
Re: higher precision doubles BGB <cr88192@hotmail.com> - 2011-08-06 12:20 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-06 23:30 +0200
Re: higher precision doubles BGB <cr88192@hotmail.com> - 2011-08-06 16:12 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-07 01:35 +0200
Re: higher precision doubles BGB <cr88192@hotmail.com> - 2011-08-06 19:26 -0700
Re: higher precision doubles supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-08-09 00:42 -0400
Re: higher precision doubles Patricia Shanahan <pats@acm.org> - 2011-08-09 04:07 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-09 14:00 +0200
Re: higher precision doubles Patricia Shanahan <pats@acm.org> - 2011-08-09 09:07 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-10 08:50 +0200
Re: higher precision doubles supercalifragilisticexpialadiamaticonormalizeringelimatisticantations <supercalifragilisticexpialadiamaticonormalizeringelimatisticantations@averylongandannoyingdomainname.com> - 2011-08-10 20:16 -0400
Re: higher precision doubles Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-08-09 10:11 -0500
Re: higher precision doubles Arne Vajhøj <arne@vajhoej.dk> - 2011-08-09 22:40 -0400
Re: higher precision doubles Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-08-09 22:06 -0500
Re: higher precision doubles BGB <cr88192@hotmail.com> - 2011-08-10 08:53 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-06 21:24 +0200
Re: higher precision doubles markspace <-@.> - 2011-08-06 13:29 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-06 23:20 +0200
Re: higher precision doubles markspace <-@.> - 2011-08-06 15:43 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-07 01:06 +0200
Re: higher precision doubles Patricia Shanahan <pats@acm.org> - 2011-08-06 16:21 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-07 01:34 +0200
Re: higher precision doubles Patricia Shanahan <pats@acm.org> - 2011-08-06 21:32 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-07 17:24 +0200
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-07 17:39 +0200
Re: higher precision doubles Patricia Shanahan <pats@acm.org> - 2011-08-07 09:26 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-07 21:23 +0200
Re: higher precision doubles Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-08-07 20:48 -0400
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-08 09:05 +0200
Re: higher precision doubles Patricia Shanahan <pats@acm.org> - 2011-08-08 05:37 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-08 19:08 +0200
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-08 19:16 +0200
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-08 19:29 +0200
Re: higher precision doubles Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-08-08 21:34 -0500
Re: higher precision doubles BGB <cr88192@hotmail.com> - 2011-08-08 13:49 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-09 01:08 +0200
Re: higher precision doubles BGB <cr88192@hotmail.com> - 2011-08-09 02:44 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-09 12:52 +0200
Re: higher precision doubles BGB <cr88192@hotmail.com> - 2011-08-09 13:15 -0700
Re: higher precision doubles BGB <cr88192@hotmail.com> - 2011-08-07 13:51 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-07 01:59 +0200
Re: higher precision doubles Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-08-08 21:03 -0500
Re: higher precision doubles Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-08-06 17:33 -0400
Re: higher precision doubles Patricia Shanahan <pats@acm.org> - 2011-08-06 14:51 -0700
Re: higher precision doubles Jan Burse <janburse@fastmail.fm> - 2011-08-07 00:57 +0200
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