[#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

[#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[#399218] Pathname#to_str withdrawn in 1.9?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> wrote:

[#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: Ryan Davis <ryand-ruby@...>
Date: 2012-09-08 21:31:34 UTC
List: ruby-talk #399118
On Sep 8, 2012, at 09:06 , Olivier Saut <osaut@airpost.net> wrote:

> Hi all,
> 
> 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. 

Have you taken a look at stdlib's matrix.rb?

= MMaattrriixx  <<  OObbjjeecctt

(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).

Note that although matrices should theoretically be rectangular, this is not
enforced by the class.

Also note that the determinant of integer matrices may be incorrectly
calculated unless you also require 'mathn'.  This may be fixed in the future.

== MMeetthhoodd  CCaattaalloogguuee

To create a matrix:
*  Matrix[*rows]                  
*  Matrix.[](*rows)               
*  Matrix.rows(rows, copy = true) 
*  Matrix.columns(columns)        
*  Matrix.diagonal(*values)       
*  Matrix.scalar(n, value)        
*  Matrix.scalar(n, value)        
*  Matrix.identity(n)             
*  Matrix.unit(n)                 
*  Matrix.I(n)                    
*  Matrix.zero(n)                 
*  Matrix.row_vector(row)         
*  Matrix.column_vector(column)   

To access Matrix elements/columns/rows/submatrices/properties: 
*   [](i, j)                      
*  #row_size                      
*  #column_size                   
*  #row(i)                        
*  #column(j)                     
*  #collect                       
*  #map                           
*  #minor(*param)                 

Properties of a matrix:
*  #regular?                      
*  #singular?                     
*  #square?                       

Matrix arithmetic:
*   *(m)                          
*   +(m)                          
*   -(m)                          
*  #/(m)                          
*  #inverse                       
*  #inv                           
*   **                            

Matrix functions:
*  #determinant                   
*  #det                           
*  #rank                          
*  #trace                         
*  #tr                            
*  #transpose                     
*  #t                             

Conversion to other data types:
*  #coerce(other)                 
*  #row_vectors                   
*  #column_vectors                
*  #to_a                          

String representations:
*  #to_s                          
*  #inspect                       
------------------------------------------------------------------------------
= CCllaassss  mmeetthhooddss::

  I
  []
  column_vector
  columns
  diagonal
  identity
  new
  row_vector
  rows
  scalar
  unit
  zero

= IInnssttaannccee  mmeetthhooddss::

  *
  **
  +
  -
  /
  ==
  []
  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

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