spline

swordfish.function.spline()

Resample X based on the specified resampleRule, closed and origin. Perform cubic spline interpolation on Y based on the resampled X.

If outputX is unspecified, return a vector of Y after the interpolation.

If outputX=true, return a tuple where the first element is the vector of resampled X and the second element is a vector of Y after the interpolation.

Parameters:

• X (Constant) – A strictly increasing vector of temporal type.

• Y (Constant) – A numeric vector of the same length as X.

• resampleRule (Constant) – A string. See the parameter rule of function resample for the optional values.

• closed (Constant, optional) –

  A string indicating which boundary of the interval is closed, by default DFLT.

  • The default value is ‘left’ for all values of rule except for ‘M’, ‘A’, ‘Q’, ‘BM’, ‘BA’, ‘BQ’, and ‘W’ which all have a default of ‘right’.

  • The default is ‘right’ if origin is ‘end’ or ‘end_day’.

• origin (Constant, optional) –

  A string or a scalar of the same data type as X, indicating the timestamp where the intervals start, by default DFLT. It can be ‘epoch’, start’, ‘start_day’, ‘end’, ‘end_day’ or a user-defined time object.

  • ’epoch’: origin is 1970-01-01

  • ’start’: origin is the first value of the timeseries

  • ’start_day’: origin is 00:00 of the first day of the timeseries

  • ’end’: origin is the last value of the timeseries

  • ’end_day’: origin is 24:00 of the last day of the timeseries

• outputX (Constant, optional) – A Boolean value indicating whether to output the resampled X, by default DFLT.