Sha256: b7e4efc9c653e9ce53f9195fec18419860501a75da1c9dcf91304653fa4f0b3b
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Size: 1000 Bytes
Versions: 5
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Stored size: 1000 Bytes
Contents
module Riak
class Client
# A float value which decays exponentially toward 0 over time.
# @private
class Decaying
attr_accessor :e
attr_accessor :p
# @param [Hash] opts options
# @option options [Float] :p (0.0) The initial value
# @option options [Float] :e (Math::E) Exponent base
# @option options [Float] :r (Math.log(0.5) / 10) Timescale
# factor - defaulting to decay 50% every 10 seconds
def initialize(opts = {})
@p = opts[:p] || 0.0
@e = opts[:e] || Math::E
@r = opts[:r] || Math.log(0.5) / 10
@t0 = Time.now
end
# Add to current value.
# @param [Float] d the value to add
def <<(d)
@p = value + d
end
# @return [Float] the current value (adjusted for the time decay)
def value
now = Time.now
dt = now - @t0
@t0 = now
@p = @p * (@e ** (@r * dt))
end
end
end
end
Version data entries
5 entries across 5 versions & 1 rubygems