Frequency (FPScript)
Determines the frequency of a data set.
Syntax
Frequency(DataSet)
The syntax of the Frequency function consists of the following parts:
Part |
Description |
|---|---|
DataSet |
The data set whose frequency is to be determined. All data structures are allowed, except scalar value und list. All real data types are permitted. |
Remarks
The result always has the data type 64-bit floating point.
The unit of the result is the same as the reciprocal of the unit of the DataSet X component. If a data set does not have an X component, then a constant sampling rate of one is assumed. If you specify a data series or a signal, the result is a scalar value with the frequency. If you specify a data matrix or a signal series, then it is a data series with one frequency per column. If no frequency could be determined, a void value will be returned.
The frequency is determined in the time domain. The signal is first searched for level crossings where the average of the amplitude is used as the reference level. The X difference of neighboring level crossings is then calculated. Periods shorter than 10% of the longest determined duration are skipped. This eliminates multiple level crossings within one period, which can be caused by noise. Of the remaining periods, the reciprocal value of the average is returned as the result.
If the argument is a list, then the function is executed for each element of the list and the result is also a list.
Available in
FlexPro Basic, Professional, Developer Suite
Examples
Frequency(Signal) |
Determines the frequency of a signal. |