K 10
svn:author
V 3
imp
K 8
svn:date
V 27
2017-03-22T19:18:47.205015Z
K 7
svn:log
V 231
Implement moving SD.

From the paper "Incremental calculation of weighted mean and variance"
by Tony Finch Februrary 2009, retrieved from
http://people.ds.cam.ac.uk/fanf2/hermes/doc/antiforgery/stats.pdf
converted to use shifting.

END