Convert singel dimention array into grid

ruby-talk
1

Hi,

I have been learning ruby for the past week and am completely hooked.
Most of the code I am producing is elegant (ruby's credit), although I
am having trouble elegantly converting a single dimension array with 16
elements into a two-dimension grid [4x4].

Here is what I have so far:

@array = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]
@grid = Array.new

i = 0
index = 0
0.upto(3) do |i|
  j = 0
  0.upto(3) do |j|
    @grid[i] = Array.new if j == 0
    @grid[i][j] = @array[index]
    index += 1
    j += 1
  end
  i += 1
end

@grid

Thanks,
Giant Cranes

···

--
Posted via http://www.ruby-forum.com/.

2

Giant Cranes wrote:

Hi,

I have been learning ruby for the past week and am completely hooked.
Most of the code I am producing is elegant (ruby's credit), although I
am having trouble elegantly converting a single dimension array with 16
elements into a two-dimension grid [4x4].

require 'enumerator'

@array = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]

result =
@array.each_slice(4) {|s| result << s }

should do the job.

Cheers,
Peter

···

__
http://www.rubyrailways.com

3

Hi --

Hi,

I have been learning ruby for the past week and am completely hooked.
Most of the code I am producing is elegant (ruby's credit), although I
am having trouble elegantly converting a single dimension array with 16
elements into a two-dimension grid [4x4].

Here is what I have so far:

@array = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]
@grid = Array.new

i = 0
index = 0
0.upto(3) do |i|
j = 0
0.upto(3) do |j|
   @grid[i] = Array.new if j == 0
   @grid[i][j] = @array[index]
   index += 1
   j += 1
end
i += 1
end

@grid

You can do:

   require 'enumerator'
   @array = [*1..16] # :slight_smile:
   @grid = *@array.enum_slice(4)

Enumerators are, in my view, a bit less transparent than most Ruby
constructs, so this may look more cryptic than it's worth. The basic
idea is that you're creating an object -- an Enumerator -- that has no
real data of its own but that represents, so to speak, the possibility
of an enumeration over @array, sliced up into groups of four. Instead
of enumerating, I've converted it to a plain array with the *
operator.

David

···

On Wed, 15 Nov 2006, Giant Cranes wrote:

--
                   David A. Black | dblack@rubypal.com
Author of "Ruby for Rails" [1] | Ruby/Rails training & consultancy [3]
DABlog (DAB's Weblog) [2] | Co-director, Ruby Central, Inc. [4]
[1] Ruby for Rails | [3] http://www.rubypowerandlight.com
[2] http://dablog.rubypal.com | [4] http://www.rubycentral.org

4

Let the golfing commence!

require 'enumerator'

@array = (1..16).to_a
@grid = Array.new(4) {|idx| Array.new(4)}

@array.each_with_index do |val, idx|
  @grid[idx/4][idx%4] = val
end

Blessings,
TwP

···

On 11/14/06, Giant Cranes <ruby-forum@gavinjoyce.com> wrote:

Hi,

I have been learning ruby for the past week and am completely hooked.
Most of the code I am producing is elegant (ruby's credit), although I
am having trouble elegantly converting a single dimension array with 16
elements into a two-dimension grid [4x4].

Here is what I have so far:

@array = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]
@grid = Array.new

i = 0
index = 0
0.upto(3) do |i|
  j = 0
  0.upto(3) do |j|
    @grid[i] = Array.new if j == 0
    @grid[i][j] = @array[index]
    index += 1
    j += 1
  end
  i += 1
end

@grid

5

Hi --

···

On Wed, 15 Nov 2006, Tim Pease wrote:

On 11/14/06, Giant Cranes <ruby-forum@gavinjoyce.com> wrote:

Hi,

I have been learning ruby for the past week and am completely hooked.
Most of the code I am producing is elegant (ruby's credit), although I
am having trouble elegantly converting a single dimension array with 16
elements into a two-dimension grid [4x4].

Here is what I have so far:

@array = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]
@grid = Array.new

i = 0
index = 0
0.upto(3) do |i|
  j = 0
  0.upto(3) do |j|
    @grid[i] = Array.new if j == 0
    @grid[i][j] = @array[index]
    index += 1
    j += 1
  end
  i += 1
end

@grid

Let the golfing commence!

require 'enumerator'

@array = (1..16).to_a
@grid = Array.new(4) {|idx| Array.new(4)}

@array.each_with_index do |val, idx|
@grid[idx/4][idx%4] = val
end

Well, if we're golfing:

require'enumerator'
g=*(1..16).enum_slice(4)

David

--
                   David A. Black | dblack@rubypal.com
Author of "Ruby for Rails" [1] | Ruby/Rails training & consultancy [3]
DABlog (DAB's Weblog) [2] | Co-director, Ruby Central, Inc. [4]
[1] Ruby for Rails | [3] http://www.rubypowerandlight.com
[2] http://dablog.rubypal.com | [4] http://www.rubycentral.org