[#399938] how to read arrary with an array — "Richard D." <lists@...>

Hello. I believe this is basic question, but I'm just starting to learn

19 messages 2012/10/02

[#400050] img src while sending email ruby cgi — Ferdous ara <lists@...>

Hi

16 messages 2012/10/05

[#400351] Drop 1st and last particular character — ajay paswan <lists@...>

What is the most efficient way to drop '#' from the first place and last

15 messages 2012/10/16

[#400374] database part of a desktop application — "Sebastjan H." <lists@...>

Hi,

14 messages 2012/10/16
[#400375] Re: database part of a desktop application — Chad Perrin <code@...> 2012/10/16

On Wed, Oct 17, 2012 at 05:28:39AM +0900, Sebastjan H. wrote:

[#400377] Re: database part of a desktop application — sto.mar@... 2012/10/17

Am 16.10.2012 23:24, schrieb Chad Perrin:

[#400389] Re: database part of a desktop application — Chad Perrin <code@...> 2012/10/17

On Wed, Oct 17, 2012 at 01:39:21PM +0900, sto.mar@web.de wrote:

[#400386] Unable to send attachment, and dealing with multiple attachment — ajay paswan <lists@...>

Hi,

11 messages 2012/10/17

[#400454] Hash with Integer key issue — Wayne Simmerson <lists@...>

Hi Im new to Ruby and am getting some unexpected results from a

18 messages 2012/10/19

[#400535] Name/symbol/object type clash? What is happening here? — Todd Benson <caduceass@...>

It's nonsense code, but I'm curious as to what is going on behind the scenes...

41 messages 2012/10/23

[#400556] Calling a method foo() or an object foo.method_call_here - both — Marc Heiler <lists@...>

Hello.

13 messages 2012/10/24

[#400650] OpenSSL ECDSA public key from private — Nokan Emiro <uzleepito@...>

Hi,

11 messages 2012/10/27

[#400680] Passing folder as argument ARGV? — Joz Private <lists@...>

Is there an easy way to pass multiple files on the command line?

15 messages 2012/10/28
[#400681] Re: Passing folder as argument ARGV? — brad smith <bradleydsmith@...> 2012/10/28

How are you traversing the directory you pass in on the command line ?

[#400697] File.readable? and /proc — Jeff Moore <lists@...>

root@nail:/projects/proc_fs# uname -a

13 messages 2012/10/28

[#400714] Marshal.load weird issue — "Pierre J." <lists@...>

Hi guys

12 messages 2012/10/28

[#400781] bug?: local variable created in if modifier not available in modified expression — "Mean L." <lists@...>

irb(main):001:0> local1 if local1 = "created"

21 messages 2012/10/30
[#400807] Re: bug?: local variable created in if modifier not available in modified expression — Bartosz Dziewoński <matma.rex@...> 2012/10/31

Oh, and in case it wasn't apparent: you can just add

[#400808] Re: bug?: local variable created in if modifier not available in modified expression — Eliezer Croitoru <eliezer@...> 2012/10/31

On 10/31/2012 4:52 PM, Bartosz Dziewoナгki wrote:

[#400809] Re: bug?: local variable created in if modifier not available in modified expression — Robert Klemme <shortcutter@...> 2012/10/31

On Wed, Oct 31, 2012 at 4:28 PM, Eliezer Croitoru <eliezer@ngtech.co.il>wrote:

[#400784] REXML & HTMLentities incorrectly map to UTF-8 — "Mark S." <lists@...>

I have some XML data (UTF 8) that I'm trying to convert into another XML

13 messages 2012/10/30

Re: 2D array strategies

From: Ryan Davis <ryand-ruby@...>
Date: 2012-10-02 20:14:22 UTC
List: ruby-talk #399980
On Oct 2, 2012, at 11:49 , Thomas Luedeke <lists@ruby-forum.com> wrote:

> Since Ruby only does 1D arrays, is there a trick for an array of arrays?
> Or is this hash territory?  How do I do the 2D equivalent of using the
> .push array command to add on more data to the original array?  Are
> there are any particular Ruby resources that I need to go read up on and
> go practice in IRB?

Unless your dimensions are quite huge, you might want to try out Matrix:

% ri Matrix
= 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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