From: Luc Traonmilin <luc.traonmilin@...>
Date: 2009-03-14T02:23:48+09:00
Subject: Re: reading data files with headers and columns

Yaj Bhattacharya a �crit :
> Hello,
>
> As a noob to Ruby, I need to read a data file with the first few lines
> as header, then the rest of the file as columns of different variables
> as arrays (in this case, 5 columns).
> After reading in the variables, I want to calculate some operations
> with each unique data field address (e.g. column3, row4), then write
> out the file with headers and data in columns.
>
> Could someone help with a few lines of basic code?
>
> Thanks in advance
> Yaj
>
>
>   
You could start with this basic piece of code (replace <tags> with your 
code):
  # here's the columns as arrays
  @column1 = []
  <rest_of_columns>
  # open file in read mode (r)
  file = File.new("<your_filename", "r")
  # read each line one after another and process it
  file.each_line do |line|
    # process as header if necessary
    # or
    # extract your variables in the line into an array
    array = line.split("<your_column_separator>")
    # assign variable to column
    @column1 << array[0]
    # ... process other columns
  end

Additionnally you can google "ruby array" and "ruby file", the API docs 
are well documented.

Luc