Research Article

A Log-Based Anomaly Detection Method with Efficient Neighbor Searching and Automatic K Neighbor Selection

Algorithm 2

The neighbor searching algorithm of MVP-tree.
Require: The sample to be detected , the distance threshold r
Ensure: The nearest sample
(1)function QueryTree
(2) Compute ,
(3)ifthen return
(4)end if
(5)ifthen return
(6)end if
(7) For the leaf tree nodes, goto (8), for the intermediate tree nodes, goto (16)
(8)fordo
(9)if and then
(10)  if, then
(11)   ifthen return
(12)   end if
(13)  end if
(14)end if
(15)end for
(16)ifthen
(17)  
(18)end if
(19)ifthen
(20)  
(21)end if
(22)ifthen
(23)  ifthen
(24)   , goto (23) for recursion
(25)  end if
(26)  ifthen
(27)   , goto (26) for recursion
(28)  end if
(29)end if
(30)ifthen
(31)  ifthen
(32)   , goto (31) for recursion
(33)  end if
(34)  ifthen
(35)   , goto (34) for recursion
(36)  end if
(37)end if
(38)end function