====TORATE====

===Parameters===

^Order^Name^Type^Desc^
|1|a|[[point list|point list]]|A list of points that have history|
|2|b|[[const]]|//Optional// Time-scale in seconds for the rate (defaults to 1 second)|

===Returns===

Returns a [[point list|point list]] - the historical values within the point are converted from a total value (usually a feed from a totaliser or counter) into a rate-of-change.

===Description===

This function is used convert points that have history (ie. from a call to [[fGETHISTORY]]) from a //counter// to a //rate of change//.

This function deals with some specific issues in the conversion process. For example, drops down to zero are //ignored//. This allows you to create a rate-of-change based on hourly or daily totals.

It also deals with situations where your //data sampling rate// and the //measurement rate// are very different. If you are sampling your data at 1-sample-per-second, but the counter is only ticking up every 10 seconds, this function will interpolate those changes over the 10 seconds.

The optional time-scale parameter controls the time-basis for the final measurement. Without the parameter, the calculated rate will be //per second//.

With a time-scale of 60, your results will be //per minute//, and at 1440 you'll have an hourly rate.

//NOTE: This function can produce rough signals if the counter is slow. We suggest using the [[fSMOOTH]] function to make your results cleaner.//

===See Also===

[[fSMOOTH]] \\
[[fTOTAL]]