Sha256: 91713a6251ed7c992c13eb35eb17959caf0eabe5a8b272ea0a6a329100d1c422
Contents?: true
Size: 921 Bytes
Versions: 53
Compression:
Stored size: 921 Bytes
Contents
module Cacher
module Weights
# Uses a logarithmic weight.
# If for a key k we have x ids, the weight is:
# w(x): log(x)
# Special case: If x < 1, then we use 0.
#
class Logarithmic < Strategy
# Generates a partial index from the given index.
#
def generate_from index
index.inject({}) do |hash, text_ids|
text, ids = *text_ids
weight = weight_for ids.size
hash[text] ||= weight.round(2) if weight
hash
end
end
# Sets the weight value.
#
# If the size is 0 or one, we would get -Infinity or 0.0.
# Thus we do not set a value if there is just one. The default, dynamically, is 0.
#
# BUT: We need the value, even if 0. To designate that there is a weight!
#
def weight_for amount
return 0 if amount < 1
Math.log amount
end
end
end
end
Version data entries
53 entries across 53 versions & 1 rubygems