Class ReciprocalFloatFunction


public class ReciprocalFloatFunction extends ValueSource
ReciprocalFloatFunction implements a reciprocal function f(x) = a/(mx+b), based on the float value of a field or function as exported by ValueSource.
When a and b are equal, and x>=0, this function has a maximum value of 1 that drops as x increases. Increasing the value of a and b together results in a movement of the entire function to a flatter part of the curve.

These properties make this an idea function for boosting more recent documents.

Example: recip(ms(NOW,mydatefield),3.16e-11,1,1)

A multiplier of 3.16e-11 changes the units from milliseconds to years (since there are about 3.16e10 milliseconds per year). Thus, a very recent date will yield a value close to 1/(0+1) or 1, a date a year in the past will get a multiplier of about 1/(1+1) or 1/2, and date two years old will yield 1/(2+1) or 1/3.

See Also:
  • Field Details

    • source

      protected final ValueSource source
    • m

      protected final float m
    • a

      protected final float a
    • b

      protected final float b
  • Constructor Details

    • ReciprocalFloatFunction

      public ReciprocalFloatFunction(ValueSource source, float m, float a, float b)
      f(source) = a/(m*float(source)+b)
  • Method Details