Module 6: Dimensionality Reduction
  Lecture 31: FastMap
 

                                            

 

 

Generalization and properties
  • The coordinate for object is given by
                                 
where,
  and,
  • are the pivots chosen in the step
  • Running time
 
  • Choosing pivots takes time
 
  • Distance computation takes time
 
  • Therefore, projection of objects takes time
 
  • Needs to be iterated for steps where is the reduced dimensionality
 
  • Hence, total running time is
  • May not work for non-metric distances
 
  • May yield negative distance squares
  • Contractive for Euclidean spaces