influxdb/influxdb — pull request #1030 by jvshahid (2014-10-20 17:38:59+00:00)
Title: Derivative aggregator with group by time without fill should take the difference between the last point of the current bucket and the last point from the previous bucket

This issue will address derivative with group by time without fill. This case has been split off from issue #334 since it may require changes that impact all aggregates. #334 will fix derivatives for no group by and group by with fill.