[#2320] Problems in mathn, rational, complex, matrix — Gavin Sinclair <gsinclair@...>
I received a message from Richard Graham mentioning a problem in the
5 messages
2004/02/01
[#2346] Patch for socket.c: control reverse lookup for every instance — Thomas Uehlinger <uehli@...>
Hi all
4 messages
2004/02/05
[#2357] Use the BasicSocket#do_not_reverse_lookup flag in Webrick — Thomas Uehlinger <uehli@...>
Hi
5 messages
2004/02/07
[#2367] Standard libraries — Dave Thomas <dave@...>
From ruby-dev summary:
60 messages
2004/02/11
[#2373] Re: Standard libraries
— matz@... (Yukihiro Matsumoto)
2004/02/11
Hi,
[#2429] Re: Standard libraries
— "NAKAMURA, Hiroshi" <nahi@...>
2004/02/13
Hi,
[#2432] Re: Standard libraries
— "Sean E. Russell" <ser@...>
2004/02/13
By the way, this issue is about a matter of taste, so the debate is somewhat
[#2437] Re: Standard libraries
— "J.Herre" <jlst@...>
2004/02/13
[#2386] Re: Standard libraries
— "NAKAMURA, Hiroshi" <nahi@...>
2004/02/12
Hi,
[#2392] Re: Standard libraries
— Mauricio Fern疣dez <batsman.geo@...>
2004/02/12
On Thu, Feb 12, 2004 at 02:58:22PM +0900, NAKAMURA, Hiroshi wrote:
[#2393] Re: Standard libraries
— Gavin Sinclair <gsinclair@...>
2004/02/12
On Thursday, February 12, 2004, 8:18:32 PM, Mauricio wrote:
[#2401] Re: Standard libraries
— "Sean E. Russell" <ser@...>
2004/02/12
On Thursday 12 February 2004 04:37, Gavin Sinclair wrote:
[#2405] Re: Standard libraries
— Gavin Sinclair <gsinclair@...>
2004/02/12
On Friday, February 13, 2004, 12:44:15 AM, Sean wrote:
[#2410] Re: Standard libraries
— "Sean E. Russell" <ser@...>
2004/02/12
(Dave Thomas: there's a question for you in the second paragraph; if you're
[#2397] PATCH: deprecate cgi-lib, getopts, importenv, parsearg from standard library — Gavin Sinclair <gsinclair@...>
Index: cgi-lib.rb
15 messages
2004/02/12
[#2398] Re: PATCH: deprecate cgi-lib, getopts, importenv, parsearg from standard library
— E F van de Laar <emiel@...>
2004/02/12
* Gavin Sinclair (gsinclair@soyabean.com.au) wrote:
[#2399] Re: PATCH: deprecate cgi-lib, getopts, importenv, parsearg from standard library
— Gavin Sinclair <gsinclair@...>
2004/02/12
On Thursday, February 12, 2004, 11:39:37 PM, E wrote:
[#2402] Re: PATCH: deprecate cgi-lib, getopts, importenv, parsearg from standard library
— matz@... (Yukihiro Matsumoto)
2004/02/12
Hi,
[#2404] Re: PATCH: deprecate cgi-lib, getopts, importenv, parsearg from standard library
— "NAKAMURA, Hiroshi" <nahi@...>
2004/02/12
Hi,
[#2422] Re: [ruby-cvs] ruby: * lib/ftools.rb: documented — "U.Nakamura" <usa@...>
Hello,
6 messages
2004/02/13
[#2449] make install not getting through rdoc phase — "David A. Black" <dblack@...>
Hi --
7 messages
2004/02/16
[#2465] PATCH: OpenStruct#initialize to yield self — Gavin Sinclair <gsinclair@...>
This is a common approach I use to object initialization; I don't know
24 messages
2004/02/19
[#2468] Change to #new (was OpenStruct#initialize to yield self)
— Dave Thomas <dave@...>
2004/02/19
[#2469] Re: Change to #new (was OpenStruct#initialize to yield self)
— Austin Ziegler <austin@...>
2004/02/19
On Fri, 20 Feb 2004 02:42:00 +0900, Dave Thomas wrote:
[#2470] Re: Change to #new (was OpenStruct#initialize to yield self)
— Carlos <angus@...>
2004/02/19
> > As more general suggestion. Could 'new' yield the new object is a block
[#2471] Re: Change to #new (was OpenStruct#initialize to yield self)
— Austin Ziegler <austin@...>
2004/02/20
On Fri, 20 Feb 2004 08:24:31 +0900, Carlos wrote:
[#2472] Re: Change to #new (was OpenStruct#initialize to yield self)
— Dave Thomas <dave@...>
2004/02/20
[#2476] Re: PATCH: OpenStruct#initialize to yield self
— matz@... (Yukihiro Matsumoto)
2004/02/20
Hi,
[#2482] Re: PATCH: OpenStruct#initialize to yield self
— Joel VanderWerf <vjoel@...>
2004/02/21
Yukihiro Matsumoto wrote:
[#2485] Re: PATCH: OpenStruct#initialize to yield self
— "J.Herre" <jlst@...>
2004/02/21
On Feb 20, 2004, at 4:33 PM, Joel VanderWerf wrote:
[#2494] rehash segfault — Nathaniel Talbott <nathaniel@...>
I don't have a lot of information on this bug at this point, but
10 messages
2004/02/24
[#2495] Re: rehash segfault
— matz@... (Yukihiro Matsumoto)
2004/02/24
Hi,
[#2498] Re: rehash segfault
— Eivind Eklund <eivind@...>
2004/02/24
On Wed, Feb 25, 2004 at 03:30:54AM +0900, Yukihiro Matsumoto wrote:
[#2504] foldl and foldr — "Sean E. Russell" <ser@...>
Sorry if I'm opening old wounds; I have a hard time believing that nobody has
6 messages
2004/02/25
Problems in mathn, rational, complex, matrix
From:
Gavin Sinclair <gsinclair@...>
Date:
2004-02-01 05:54:16 UTC
List:
ruby-core #2320
I received a message from Richard Graham mentioning a problem in the
Matrix class. Below is an extract.
--Gavin --------------------- 8< ----------------------------------
The stdlib documentation drew my attention with the Matrix
class example for determinant.
http://www.ruby-doc.org/stdlib/libdoc/matrix/rdoc/classes/Matrix.html#M000064
Matrix[[7,6], [3,9]].determinant
=> 63
Call me a geek, but I instantly saw that this was the wrong
answer. I think Ruby is great so I figured the documentation
must be in error. To check, I tried it locally and was astonished
when I got the same wrong answer! Say it isn't so! 8-O
After some investigation, the source of the immediate "problem"
is the statement:
q = a[i][k] / akk
in the source code for the determinant. With integer operands,
you get integer quotients. Mayhem follows.
Further investigation shows that the "rational" library has
a "quo" method that fixes the above problem, but the alias
of "/" to "quo" only occurs in "mathn"!
It seems that the mathn, rational, complex, and matrix libraries
are not as orthogonal as one would expect. I wish they were.
So, at present; rational, complex, and matrix libraries
should not be "required" unless the necessary functionality of
mathn is somehow maintained. I did not investigate further so I
don't know what other traps await "requirers" of the individual
libraries.
Until the library source code is changed (will it ever?), it
seems users should be cautioned to just require 'mathn' to
ensure proper functionality.