From: John Joyce <dangerwillrobinsondanger@...>
Date: 2007-10-18T01:32:34+09:00
Subject: Re: extracting values from consecutive lines


On Oct 17, 2007, at 11:03 AM, baptiste Auguié wrote:

>
> Hello,
>
> This is a basic question, as I'm very new to Ruby. I have a text  
> file 'input.dat' containing the following data and text:
>
>
>> some text
>> some text...
>>
>> angle          value1            value2
>>
>> 156.00        3.3688E-03        1.7040E-03
>> 157.00        3.2919E-03        1.7118E-03
>> 158.00        3.2140E-03        1.7190E-03
>> 159.00        3.1354E-03        1.7258E-03
>> 160.00        3.0560E-03        1.7320E-03
>> 161.00        2.9760E-03        1.7378E-03
>> 162.00        2.8956E-03        1.7431E-03
>> 163.00        2.8148E-03        1.7479E-03
>> 164.00        2.7338E-03        1.7523E-03
>> 165.00        2.6526E-03        1.7562E-03
>> 166.00        2.5714E-03        1.7597E-03
>> 167.00        2.4902E-03        1.7628E-03
>
>
> I would like to extract the 3 columns of data for several  
> consecutive lines (say, from angle = 158 to 165). These values  
> should be stored in some array or vector. How can I do that in Ruby?
>
> Many thanks,
>
> baptiste
>
>
>
>
Many ways to approach it of course.
You could use CSV or FasterCSV since your data file is lines (rows)  
with columns separated by tabs or spaces.
CSV or FasterCSV might be more useful to do other things also with  
the data file.
but you can also just read the first 3 or 4 bytes of each line to  
find the lines you want.