Sha256: d5eaf69f079d6639960821b8acfd9e504813c7ff37b87aba98b57d17652bb792
Contents?: true
Size: 1017 Bytes
Versions: 10
Compression:
Stored size: 1017 Bytes
Contents
module LabTech
module Percentile
extend self
MIN_PERCENTILE = 0
MAX_PERCENTILE = 100
def call(pct, list)
# Make sure this list is actually sorted
unless sorted?(list)
fail "Sorry, this isn't sorted: #{list.inspect}"
end
msg = "Please pass an integer between #{MIN_PERCENTILE} and #{MAX_PERCENTILE}, not #{pct.inspect}"
raise ArgumentError, msg unless pct.kind_of?(Integer)
raise ArgumentError, msg unless (MIN_PERCENTILE..MAX_PERCENTILE).cover?(pct)
return list.first if pct == MIN_PERCENTILE # Avoid the need for a bounds check later
return list.last if pct == MAX_PERCENTILE # By definition, I guess
i = ( 0.01 * pct * list.length ).ceil - 1 # Don't ask me why this works
list[ i ]
end
private
def sorted?(list)
ret_val = true
list.each_cons(2) do |a,b|
if a <= b
next
else
ret_val = false
break
end
end
ret_val
end
end
end
Version data entries
10 entries across 10 versions & 1 rubygems