From: ES <ruby-ml@...>
Date: 2005-05-11T01:35:07+09:00
Subject: Re: help with reading part of textfile into matrix

rgilaard@few.vu.nl wrote:
> Oof course I am confused a s a ruby newbie!!
> 
> However,
> I've made this out of your post:
> matrix = []
> 
> DATA = File.new("testfile.txt", "r")
> DATA.each do | line |
> if /^((?:\s+(?:\d+))+)/ =~ line
> matrix << $1.split.map{|value| value.to_i}
> end
> end
> 
> p matrix
> puts matrix[2,2]
> DATA.close
> 
> But this gives me as result 
> 707
> 293
> 441
> 
> while I would expect 441.
> 
> What is going on?

Here you would want 'puts matrix[2][2]'.

Your form actually returns a slice,
i.e. "starting from element 2, give
me 2 elements" (and there is only one).

> Brgds
> Robert
> 
> Quoting Brian Schr�der <ruby.brian@gmail.com>:
> 
> 
>>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/
>>
>>multilingual _non rails_ ruby based vocabulary trainer:
>>http://www.vocabulaire.org/ | http://www.gloser.org/ |
>>http://www.vokabeln.net/
>>

E

-- 
template<typename duck>
void quack(duck& d) { d.quack(); }