Class Searches

java.lang.Object
org.apache.commons.statistics.inference.Searches
final class Searches extends Object
Search utility methods.
Since:
1.1

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    private static final int
    BINARY_SEARCH
    Range threshold to use a binary search.

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    private
    Searches()
    No instances.

  • Method Summary

    Modifier and Type
    Method
    Description
    (package private) static int
    searchAscending(int a, int b, double x, IntToDoubleFunction value)
    Conduct a search between a inclusive and b inclusive to find the highest index where value <= x.
    (package private) static int
    searchDescending(int a, int b, double x, IntToDoubleFunction value)
    Conduct a search between a inclusive and b inclusive to find the lowest index where value <= x.

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

  • Constructor Details

    • Searches

      private Searches()
      No instances.

  • Method Details

    • searchDescending

      static int searchDescending(int a, int b, double x, IntToDoubleFunction value)
      Conduct a search between a inclusive and b inclusive to find the lowest index where value <= x. The values must be in descending order. The method is functionally equivalent to: 
      
i = b + 1
while (i > a AND value(i - 1) <= x)
   i = i - 1
return i

      The function is only evaluated between the closed interval [a, b]. Special cases:

      • If value(a) <= x the returned index is a.
      • If value(b) > x the returned index is b + 1.
      Parameters:
      a - Lower limit (inclusive).
      b - Upper limit (inclusive).
      x - Target value.
      value - Function to evaluate the value at an index.
      Returns:
      the minimum index where value(i) <= x.

    • searchAscending

      static int searchAscending(int a, int b, double x, IntToDoubleFunction value)
      Conduct a search between a inclusive and b inclusive to find the highest index where value <= x. The values must be in ascending order. The method is functionally equivalent to: 
      
i = a - 1
while (i < b AND value(i + 1) <= x)
   i = i + 1
return i

      The function is only evaluated between the closed interval [a, b]. Special cases:

      • If value(a) > x the returned index is a - 1.
      • If value(b) <= x the returned index is b.
      Parameters:
      a - Lower limit (inclusive).
      b - Upper limit (inclusive).
      x - Target value.
      value - Function to evaluate the value at an index.
      Returns:
      the maximum index where value(i) <= x.