[#398788] Constructor or a Method — Rubyist Rohit <lists@...>

Take for instance this code:

13 messages 2012/09/01

[#398896] how to sum element of array — Edward QU <lists@...>

dear all

19 messages 2012/09/04

[#398936] best coding for limiting a value — Regis d'Aubarede <lists@...>

A) result=value<min ? min : (value > max ? max : value)

17 messages 2012/09/04

[#398962] Long calculation & time limit — toto tartemolle <lists@...>

Hello,

17 messages 2012/09/05

[#398964] Compiling ruby from source on windows — GPad <peterpan105105@...>

Hi to all,=0AI'm trying to compile ruby on my windows 7. I have already a r=

10 messages 2012/09/05

[#398997] OpenURI open method problem — "Derek T." <lists@...>

The code I am referring to looks like this:

12 messages 2012/09/05

[#399002] Parsing through downloaded html — Sybren Kooistra <lists@...>

Hi all,

28 messages 2012/09/06

[#399012] "Hiding" pictures(and source code if it's possible) — "Damián M. González" <lists@...>

Ey guys, how are you?

11 messages 2012/09/06

[#399083] regix in grep or something like this — Ferdous ara <lists@...>

Hi

12 messages 2012/09/07

[#399206] please help me with making script — Charmaine Willemsen <lists@...>

In this example i like to parse birthday and sexe

11 messages 2012/09/11

[#399218] Pathname#to_str withdrawn in 1.9? — matt@... (Matt Neuburg)

Just getting started experimenting with Ruby 1.9 (1.9.3) and my scripts

13 messages 2012/09/12

[#399227] Breaking Down the Block — incag neato <lists@...>

Can someone please explain in plain english how this block treats the

20 messages 2012/09/13

[#399244] ruby Range to array that acts like time objects? — "Jermaine O." <lists@...>

Hello everybody,

15 messages 2012/09/13

[#399293] Ruby on Ubuntu 12.04 LST — Bojan Jordanovski <lists@...>

Hello everybody,

13 messages 2012/09/14

[#399298] wow, YAML / Psych in 1.9.3 is *slow*! — matt@... (Matt Neuburg)

I just started trying Ruby 1.9.3, coming from Ruby 1.8.7, and was

12 messages 2012/09/14

[#399304] Ruby 1.9.3 and OS X Mountain Lion — sto.mar@...

Hi all,

16 messages 2012/09/14

[#399343] Class variables or Class singleton variables? — "Damián M. González" <lists@...>

Guys, how are you?

18 messages 2012/09/15

[#399386] Ruby - is it worth the effort? — neomex <neomex@...>

Hello,

19 messages 2012/09/17
[#399406] Re: Ruby - is it worth the effort? — Roger Pack <lists@...> 2012/09/17

Unfortunately with Ruby for me it's typically "fun and fast development"

[#399409] Re: Ruby - is it worth the effort? — Peter Zotov <whitequark@...> 2012/09/17

Roger Pack писал 17.09.2012 22:06:

[#399491] Re: Ruby - is it worth the effort? — Robert Klemme <shortcutter@...> 2012/09/19

On Mon, Sep 17, 2012 at 8:20 PM, Peter Zotov <whitequark@whitequark.org> wr=

[#399421] Encoding question — Thomas Bednarz <lists@...>

I am new to ruby and play around with it a little bit at the moment. I

17 messages 2012/09/17

[#399441] Bug or feature — Damjan Rems <lists@...>

There has probably been some discussion about this problem so sorry if I

13 messages 2012/09/18

[#399451] Class variables — Aleksander Ciesielski <neomex@...>

Is it obligatory to use instance variables in classes? Can't we just

17 messages 2012/09/18

[#399479] Ruby SQL Select Sum 2 Columns? — Courtney Fay <lists@...>

I have the following definition which is looking at an apache database,

12 messages 2012/09/18

[#399556] still learning by doing - connecting rooms in a game — "Sebastjan H." <lists@...>

Hi,

28 messages 2012/09/20
[#399570] Re: still learning by doing - connecting rooms in a game — Henry Maddocks <hmaddocks@...> 2012/09/20

[#399574] Re: still learning by doing - connecting rooms in a game — "Sebastjan H." <lists@...> 2012/09/21

Henry Maddocks wrote in post #1076876:

[#399575] Re: still learning by doing - connecting rooms in a game — Henry Maddocks <hmaddocks@...> 2012/09/21

[#399576] Re: still learning by doing - connecting rooms in a game — "Sebastjan H." <lists@...> 2012/09/21

Could you be so kind as to suggest another book? I mean there are many

[#399585] Re: still learning by doing - connecting rooms in a game — "Sebastjan H." <lists@...> 2012/09/21

Sebastjan H. wrote in post #1076909:

[#399572] How would you allow variable from specific list of Fixnum? — Eliezer Croitoru <eliezer@...>

I have:

11 messages 2012/09/21

[#399623] Very important question - survey — Marc Heiler <lists@...>

Is matz more like a ninja or more like a samurai?

11 messages 2012/09/22

[#399695] inject problem — Roelof Wobben <rwobben@...>

26 messages 2012/09/25

[#399714] could initialize return an existing object instead of a new instance? — Gary Weaver <lists@...>

Is it possible for initialize to return an existing object instead of a

9 messages 2012/09/25

[#399811] Good book for getting started with Ruby? [I code Python!] — Alec Taylor <alec.taylor6@...>

I've learned programming in C++, Python and PHP at University. (also

12 messages 2012/09/28

[#399815] calcaulation with unknown numbers of numbers and options fail — Roelof Wobben <rwobben@...>

11 messages 2012/09/28

Re: Using ruby for scientific computing

From: Olivier Saut <osaut@...>
Date: 2012-09-09 07:33:32 UTC
List: ruby-talk #399125
Le 8 sept. 2012 =E0 23:31, Ryan Davis <ryand-ruby@zenspider.com> a =E9crit=
 :

>=20
> On Sep 8, 2012, at 09:06 , Olivier Saut <osaut@airpost.net> wrote:
>=20
>> Hi all,
>>=20
>> For pedagogic purposes, I am trying to solve simple partial =
differential
>> equations (say a diffusion equation on a regular mesh in 2D) with =
Ruby.
>> Using the NArray gem, I have built a satisfactory tool from an =
interface
>> (and ease of use) point of view but the performance are suboptimal.=20=

>=20
> Have you taken a look at std lib's matrix.rb?

No, I'll check it. In particular there is a LU decomposition method =
implemented which could help me a lot.

Thanks,=20

>=20
> =3D M=08Ma=08at=08tr=08ri=08ix=08x =08 <=08< =08 O=08Ob=08bj=08je=08ec=08=
ct=08t
>=20
> (from ruby core)
> =
--------------------------------------------------------------------------=
----
> The Matrix class represents a mathematical matrix, and provides =
methods for
> creating special-case matrices (zero, identity, diagonal, singular, =
vector),
> operating on them arithmetically and algebraically, and determining =
their
> mathematical properties (trace, rank, inverse, determinant).
>=20
> Note that although matrices should theoretically be rectangular, this =
is not
> enforced by the class.
>=20
> Also note that the determinant of integer matrices may be incorrectly
> calculated unless you also require 'mathn'.  This may be fixed in the =
future.
>=20
> =3D=3D M=08Me=08et=08th=08ho=08od=08d =08 C=08Ca=08at=08ta=08al=08lo=08o=
g=08gu=08ue=08e
>=20
> To create a matrix:
> *  Matrix[*rows]                 =20
> *  Matrix.[](*rows)              =20
> *  Matrix.rows(rows, copy =3D true)=20
> *  Matrix.columns(columns)       =20
> *  Matrix.diagonal(*values)      =20
> *  Matrix.scalar(n, value)       =20
> *  Matrix.scalar(n, value)       =20
> *  Matrix.identity(n)            =20
> *  Matrix.unit(n)                =20
> *  Matrix.I(n)                   =20
> *  Matrix.zero(n)                =20
> *  Matrix.row_vector(row)        =20
> *  Matrix.column_vector(column)  =20
>=20
> To access Matrix elements/columns/rows/submatrices/properties:=20
> *   [](i, j)                     =20
> *  #row_size                     =20
> *  #column_size                  =20
> *  #row(i)                       =20
> *  #column(j)                    =20
> *  #collect                      =20
> *  #map                          =20
> *  #minor(*param)                =20
>=20
> Properties of a matrix:
> *  #regular?                     =20
> *  #singular?                    =20
> *  #square?                      =20
>=20
> Matrix arithmetic:
> *   *(m)                         =20
> *   +(m)                         =20
> *   -(m)                         =20
> *  #/(m)                         =20
> *  #inverse                      =20
> *  #inv                          =20
> *   **                           =20
>=20
> Matrix functions:
> *  #determinant                  =20
> *  #det                          =20
> *  #rank                         =20
> *  #trace                        =20
> *  #tr                           =20
> *  #transpose                    =20
> *  #t                            =20
>=20
> Conversion to other data types:
> *  #coerce(other)                =20
> *  #row_vectors                  =20
> *  #column_vectors               =20
> *  #to_a                         =20
>=20
> String representations:
> *  #to_s                         =20
> *  #inspect                      =20
> =
--------------------------------------------------------------------------=
----
> =3D C=08Cl=08la=08as=08ss=08s =08 m=08me=08et=08th=08ho=08od=08ds=08s:=08=
:
>=20
>  I
>  []
>  column_vector
>  columns
>  diagonal
>  identity
>  new
>  row_vector
>  rows
>  scalar
>  unit
>  zero
>=20
> =3D I=08In=08ns=08st=08ta=08an=08nc=08ce=08e =08 =
m=08me=08et=08th=08ho=08od=08ds=08s:=08:
>=20
>  *
>  **
>  +
>  -
>  /
>  =3D=3D
>  []
>  clone
>  coerce
>  collect
>  column
>  column_size
>  column_vectors
>  compare_by_row_vectors
>  det
>  determinant
>  eql?
>  hash
>  init_rows
>  inspect
>  inv
>  inverse
>  inverse_from
>  map
>  minor
>  rank
>  regular?
>  row
>  row_size
>  row_vectors
>  singular?
>  square?
>  t
>  to_a
>  to_s
>  tr
>  trace
>  transpose
>=20

						       	                	=
- Olivier


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