stats stuff

stats-crap.rb

arr = []
loop do
	s = gets.chomp
	break if s == "END"
	arr << s.to_f	
end

sum = 0
arr.map{|e| sum += e}

puts "sum"
puts sum

puts "mean"
puts sum.to_f / arr.length

arr.sort!

puts "all the elements"
puts arr.join(" ")
puts arr.length

puts "median"
if arr.length % 2 == 0
	med = arr[arr.length/2-1] + arr[arr.length/2]
	med /= 2.0
	puts med
else
	puts arr[arr.length/2]
end

f = {}
arr.uniq.map{|e| f[e] = 0}
arr.map{|e| f[e] += 1}

puts "frequencies:"
f.each do |k,v|
	puts "#{k} #{v}"
end

puts "range "
puts arr.last - arr.first

sqsum = 0.0
arr.map{|e| sqsum += e*e}

sum = sum.to_f

variance = (sqsum - sum*sum / arr.length) / (arr.length-1)

puts "variance" 
puts variance

puts "stdev"
puts variance ** 0.5