Research Article

HOVA-FPPM: Flexible Periodic Pattern Mining in Time Series Databases Using Hashed Occurrence Vectors and Apriori Approach

Algorithm 1

The proposed algorithm.
Input: event E, Occ_vec All Events S, Max_Pattern_Length, Prev_Keys
Output: a list of mined patterns
NP = {}, New_Events = slice_even (S, Prev_Keys) Periodic = periodicity (E, Occ_vec,lengthofOcc_vec,Confidence) for i in {O1, ..., On} of Period do
  for Key in {K1, ..., Kn} of New_Events do for Item
       in {I1, ..., In} of
       New_Events(Keys) do
       Difference ← Periodic − Item if
    continue
   end   Difference > Max_Pattern_Length
       then
       if Item > Periodic then if
       Difference > KeySize then
       star_count = Difference−
       KeySize
   end
      if star_count > star_limit then
   end
       continue
       end
   end   stars = calculate_stars(star_count) pattern_key = E + stars + Key
   end   patterns_with_stars = Periodic[i] NP ∪ pattern_with_star
else
       pattern_key = Key + E patterns_without_stars = Periodic[i]
       NP ∪ pattern_without_star_count
   end  if Difference > KeySize then
       star_count = Difference − KeySize
else
       if star_count > star_limit then
       continue
   end   end
   end    stars = calculate_stars (star_count) pattern_key = Key + stars + E pattern_with_star
  end    =Periodic[i] NP ∪ pattern_with_star
  pattern_key = Key + Epattern_without_star = Periodic[i] NP ∪
  pattern_without_star
 end for j in {Key1, ..., Keyn} of New_Events do
 NL_Patterns = calc_next (New_Events, NP, Max_Pattern_Length) NP ∪
  update (NL_Patterns)
   end
  end
ReturnNP