hist.rb

#!/usr/bin/ruby 


binwidth = ARGV[0].to_f
filename = ARGV[1]
rand_file_name = "rand_file-#{(rand*1000000).to_i}.data"

nums = File.open(filename, "r") {|f| f.readlines}.collect {|n| n.to_f }
binned_data = {}
nums.each do |n|
  bin = binwidth * (n/binwidth).to_i + binwidth/2.0
  binned_data[bin] ||= 0
  binned_data[bin] +=  1
end

ff = File.open(rand_file_name, "w")
binned_data.keys.sort.each {|k| ff.puts "#{k}, #{binned_data[k]}"}
ff.close

gnuplot_script = "plot '#{rand_file_name}' u 1:2 w boxes;"
`gnuplot -p -e "#{gnuplot_script}"`

# File.delete(rand_file_name)



# puts "histogramming #{filename} with binwidth = #{binwidth}"
# 
# gnuplot_script = <<GNUPLOT
# binwidth=[[BINWIDTH]]; bin(x,width)=width*floor(x/width) + binwidth/2.0; plot '[[FILENAME]]' using (bin(\\$1,binwidth)):(1.0) smooth freq with boxes;
# GNUPLOT
# 
# gnuplot_script = <<GNUPLOT
# binwidth=[[BINWIDTH]]; bin(x,width)=width*floor(x/width) + binwidth/2.0; plot '[[FILENAME]]' using (bin(\\$1,binwidth)):(1.0) with boxes;
# GNUPLOT
# 
# 
# gnuplot_script.gsub!("[[BINWIDTH]]", binwidth)
# gnuplot_script.gsub!("[[FILENAME]]", filename)
# 
# puts "#{gnuplot_script}"
# 
# `gnuplot -p -e "#{gnuplot_script}"`