Module 6: Dimensionality Reduction
  Lecture 31: FastMap
 

                                            

 

 

Analysis of projection
  • Utilizes Pythagoras' theorem
  • Assumes distance function is a metric distance
  • Works fine for the first coordinate in the reduced dimensionality
  • Need a way to extend and generalize this
  • Assume an original dimensionality of
  • After first step project everything onto a -hyperdimensional plane which is perpendicular to line
  • Modify distance to work for dimensions
  • Modified distance may not be a metric distance any more
  • Will be a metric if in Euclidean space