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module Query
# Calculates weights for certain combinations.
#
class Weights # :nodoc:all
attr_reader :weights
#
#
def initialize weights = {}
@weights = weights
end
# Get the weight of an allocation.
#
def weight_for clustered
@weights[clustered] || 0
end
# Returns an energy term E for allocation. this turns into a probability
# by P(allocation) = 1/Z * exp (-1/T * E(allocation)),
# where Z is the normalizing partition function
# sum_allocations exp(-1/T *E(allocation)), and T is a temperature constant.
# If T is high the distribution will be close to equally distributed.
# If T is low, the distribution will be the indicator function
# for min (E(allocation))…
#
# ...
#
# Just kidding. It's far more complicated than that. Ha ha ha ha ;)
#
# Note: Cache this if more complicated weighings become necessary.
#
def score combinations
# TODO Or hide: combinations#to_weights_key (but it's an array, so…)
#
# TODO combinations could cluster uniq as combinations are added (since combinations don't change).
#
# TODO Or it could use actual combinations? Could it? Or make combinations comparable to Symbols.
#
weight_for combinations.map(&:category_name).clustered_uniq_fast
end
# Are there any weights defined?
#
def empty?
@weights.empty?
end
def == other
@weights == other.weights
end
# Prints out a nice representation of the configured weights.
#
def to_s
@weights.to_s
end
end
end
Version data entries
12 entries across 12 versions & 1 rubygems