simple ruby console histogram generator

gistfile1.rb

# Pass in an enumeration of data and
# (optionally) a block to extract the grouping aspect of the data.
#
# Optional: sort_by lambda (operates on group key and count)
#
def puts_hist(data, sort_by:nil, &blk)
  data   = data.map(&blk) if blk
  counts = data.each_with_object(Hash.new(0)) {|k,h| h[k]+=1}
  max    = counts.values.max
  width  = Pry::Terminal.size!.last
  width0 = counts.keys.map{|k|k.to_s.length}.max
  width1 = width - width0 - 3
  div    = [1, max / width1.to_f].max
  puts "max: %d; widths: %d, %d; divisor: %0.3f" % [max, width0, width1, div]
  counts = counts.sort_by(&sort_by)  if sort_by
  counts.each do |k,c|
    puts "%#{width0}s: %-#{width1}s" % [k, "#"*((c/div).round)]
  end
  counts
end