followers_v_pr.rb

#!/usr/bin/env ruby

#
# Installing rsruby gem:
#
# sudo apt-get install r-base
# sudo gem install rsruby -- --with-R-dir=/usr/lib/R --with-R-include=/usr/share/R/include
# sudo ln -s /usr/lib/R/lib/libR.so /usr/lib/libR.so
# export R_HOME=/usr/lib/R
#
require 'rubygems'
require 'rsruby'

class RplotXY
  attr_accessor :r
  
  def initialize
    @r = RSRuby.instance
  end

  def plot x,y
    x.map!{|f| Math.log(f) rescue 0.0} # pay no attention here, move along
    y.map!{|f| Math.log(f) rescue 0.0} # pay no attention here, move along
    r.png("data.png")
    fit = r.lsfit(x,y) # this is absurd, it returns every goddamned point too
    args = {
      'x'    => x,
      'y'    => y,
      'pch'  => '.',
      'xlab' => 'log(trstrank)',
      'ylab' => 'log(followers)'}
    r.plot(args)
    intercept = fit["coefficients"]["Intercept"]
    slope     = fit["coefficients"]["X"]
    r.abline(intercept, slope, 'col' => "red")
    r.title('main' => "Followers vs Raw TrstRank")
    r.text(r.c(2), r.c(12), "y = #{slope}*x + #{intercept}")
    r.eval_R("dev.off()")
  end
  
end

artist = RplotXY.new
data   = File.readlines(ARGV[0]).map{|line| line.strip.split("\t").map{|t| t.to_f}}
x_points = data.map{|row| row.first}
y_points = data.map{|row| row.last }

artist.plot x_points, y_points