From: "Brian Schröder" <ruby.brian@...>
Date: 2005-05-10T22:47:39+09:00
Subject: Re: help with reading part of textfile into matrix

On 10/05/05, rgilaard@few.vu.nl <rgilaard@few.vu.nl> wrote:
> Dear all,
> 
> I am new to Ruby and I'm looking for a way to use Ruby (1.8) to read a part of
> a textfile into a matrix.
> 
> The textfile lokks like:
> 
> === Confusion Matrix ===
> 
>      a     b     c   <-- classified as
>   7494  4044   100 |     a = WEL
>   2039 18691    11 |     b = NIET
>    707   293   441 |     c = NOOIT
> 
> So what i want is that this matrix is read into a matrix variable in a ruby
> program which I can use then to manipulate in every way I want.
> 
> Can someone help me with this?
> 
> I figured out that I could maybe use a regexp /\s*a\s*/ to search for the line
> with a b c
> Then I skip that line and start to read the following line position by position
> into the first row of the 3-by-3 matrix.
> 
> How could this be done?
> 
> Thanks in advance,
> Robert Gilaard
> 

Confused? ;-)

$ cat confusion.rb 
matrix = []

DATA.each do | line |
  if /^((?:\s+(?:\d+))+)/ =~ line
    matrix << $1.split.map{|value| value.to_i}
  end
end

p matrix

__END__
     a     b     c   <-- classified as
 7494  4044   100 |     a = WEL
 2039 18691    11 |     b = NIET
  707   293   441 |     c = NOOIT

$ ruby confusion.rb 
[[7494, 4044, 100], [2039, 18691, 11], [707, 293, 441]]

regards,

Brian Schr�der

-- 
http://ruby.brian-schroeder.de/

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