comparision.rb

require 'memory_profiler'
require 'daru'

array1 = (300.times.map { ('a'..'z').to_a.shuffle }).to_a

array2 = ['a'*26]*100 + ['b'*26]*100 + ['c'*26]*100

report = MemoryProfiler.report do
  a = Daru::Index.new array1
end

report.pretty_print

report = MemoryProfiler.report do
  b = Daru::CategoricalIndex.new array2
end

report.pretty_print

# Result are following:
# a takes up 306688
# b takes up  22001