ZHANG, Ruda October 04, 2018:  Corrections to manifold learning [3da1eb0]
ZHANG, Ruda September 30, 2018:  CSS redesign; more edits. [dd44d96]
Ruda Zhang August 07, 2016:  Replace tab with two spaces. [adaa87b]
Ruda Zhang June 26, 2016:  one sentence per line [e15360a]
Ruda Zhang June 26, 2016:  add category tag to wiki pages [a9b356c]
Ruda Zhang June 26, 2016:  use canonical filename and no internal H1 [eeca8ff]