Draw a histogram from a CSV on the command line

histo.rb

#!/usr/bin/env ruby

COLUMNS_TO_USE = 40.0
histo = []

0.upto(9) { |i| histo[i] = 0 }

field_to_parse = ARGV.shift.to_i
ARGF.each do |line|
  fields = line.split(/,/)
  score = fields[field_to_parse].to_i

  histo[(score * 0.1).floor] += 1
end

max   = histo.sort.last
scale = COLUMNS_TO_USE / max

puts "\n\n\n"
puts " 0\n ||"
histo.each { |l| print " ||", '=' * (l.to_i * scale), "\n" }
puts 100
puts "\n\n\n"

Draw a Histogram from a CSV on the Command Line

Sideways ASCII art FTW.

Usage:

$ histo.rb 2 my_csv_file

2 being the column number to grab from the CSV

Looks like:

 0
 ||
 ||=
 ||======
 ||========
 ||============
 ||================
 ||=========
 ||============
 ||===========
 ||========================================
 ||====================================
100