anchor.diff:  
   In the second example, documents with a field value between 2013-09-12 and 2013-09-22 would get a weight of 1.0 and documents which are 15 days from that date a weight of 0.5.
   
  -
  +===== Supported decay functions
   
   The `DECAY_FUNCTION` determines the shape of the decay:
   
  -[horizontal]
   `gauss`::
  -
  ++
  +--
   Normal decay, computed as:
  +
  +image:images/Gaussian.png[]
  +
  +where image:images/sigma.png[] is computed to assure that the score takes the value `decay` at distance `scale` from `origin`+-`offset`
  +
  +image:images/sigma_calc.png[]
  +
  +See <<gauss-decay>> for graphs demonstrating the curve generated by the `gauss` function.
  +
  +--
  +
  +`exp`::
   +
  -image:images/Gaussian.png[]
  -
  -where image:images/sigma.png[] is computed to assure that the score takes the value `decay` at distance `scale` from `origin`+-`offset`
  -
  -image:images/sigma_calc.png[]
  -
  -[horizontal]
  -`exp`::
  -
  +--
   Exponential decay, computed as:
  +
  +image:images/Exponential.png[]
  +
  +where again the parameter image:images/lambda.png[] is computed to assure that the score takes the value `decay` at distance `scale` from `origin`+-`offset`
  +
  +image:images/lambda_calc.png[]
  +
  +See <<exp-decay>> for graphs demonstrating the curve generated by the `exp` function.
  +
  +--
  +
  +`linear`::
   +
  -image:images/Exponential.png[]
  -
  -where again the parameter image:images/lambda.png[] is computed to assure that the score takes the value `decay` at distance `scale` from `origin`+-`offset`
  -
  -image:images/lambda_calc.png[]
  -
  -[horizontal]
  -`linear`::
  -
  +--
   Linear decay, computed as:
  -+
  +
   image:images/Linear.png[].
   
   
  
positive.code: `min`::         min of query score and function score
  
  By default, modifying the score does not change which documents match. To exclude
  documents that do not meet a certain score threshold the `min_score` parameter can be set to the desired score threshold.  
  
  ==== Score functions
  
  The `function_score` query provides several types of score functions.
  
  ===== Script score
  
  The `script_score` function allows you to wrap another query and customize
  the scoring of it optionally with a computation derived from other numeric
  
negative.code: defined location but "BnB Bellevue" is cheaper, so it gets a multiplier
  of 0.86 whereas "Backpack Nap" gets a value of 0.66.
  
  [[exp-decay]]
  ===== Exponential decay, keyword `exp`
  
  When choosing `exp` as the decay function in the above example, the
  