From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2011-11-30T03:10:07+09:00
Subject: Re: Ruby and ASCII matrix

On Tue, Nov 29, 2011 at 6:59 PM, Adam Mulan <amulan91@gmail.com> wrote:
> Hello,
> I have prepared the following code (it almost works for even size
> strings). I wanna create 2-chars vectors from ASCII codes and push them
> on the stack, then proceed by algebra functions (Hill cipher). I don't
> want use encryption library, because it's academic exercise (I can use
> any language).
>
> #!/usr/bin/env ruby
>
> require 'matrix'
>
> print "Message: "
> msg = gets.chomp
>
> # stack with matrices
> stack = []
> # make matrix with column
> i = 0
> column = [0, 0]
> msg.each_byte do |char|
>  # create two-element vector
>  column[0] = char if i == 0
>  if i == 1
>    column[1] = char
>    # put vector on stack
>    puts "Input data: #{column[0]}, #{column[1]}"
>    tmp = Matrix[column[0], column[1]]

I get an error here, cause Matrix#[] is expecting an array.

>    puts "Output data: #{tmp[0,0]} #{tmp[0,1]}"
>    stack.push(tmp)
>    i = 0
>    next
>  end
>  i += 1
> end
>
> The output data is invalid, i don't store input data in tmp Matrix class
> variable. Why?

Your algorithm can be made simpler, using each_slice:


#!/usr/bin/env ruby

require 'matrix'

print "Message: "
msg = gets.chomp

# stack with matrices
stack = []
msg.each_byte.each_slice(2) do |two_char_array|
  stack.push Matrix[two_char_array]
end
p stack

Typing "test" as the message I get:

[Matrix[[116, 101]], Matrix[[115, 116]]]

Hope this helps.

Jesus.