normalized distance between samples produced by this class.
maximum time allowed between updates before NaN values will be used.
normalized values will be passed to the this function.
Update with a new sample and return the value for a complete interval if one is available.
Update with a new sample and return the value for a complete interval if one is available.
(Since version ) see corresponding Javadoc for more information.
Normalizes metrics in a manner similar to RRDtool.