graphite-project/graphite-web — pull request #5 by scobal (2012-05-28 13:46:14+00:00)
Title: Add absolute function

I've added the mathematical abs function. I need this for alerting (with https://github.com/scobal/seyren) on the result of Holt Winters aberrations, eg:

holtWintersAberration(sumSeries(business.downloads))

can be positive or negative. To set warning and error thresholds correctly I need to be able to get an absolute value, eg:

absolute(holtWintersAberration(sumSeries(business.downloads)))