Non-Parametric Time Series predictor predicts future values by sampling from past observations. The sampling weights can follow either a uniform or exponentially decreasing distribution, and optionally take into account the seasonality of the time series.
For a non-seasonal NPTS model, past observations can be sampled using a uniform distribution, or an exponential distribution whose probability decreases with the time distance to the observation (recent observations thus have a higher probability to be sampled than distant past ones).
For a seasonal NPTS model, time features based on the frequency of the time series are computed. Past observations can either be sampled using a uniform distribution amongst observations with the same values for the computed time features, or using an exponential distribution whose probability decreases with both the time distance to the past observation and the distance w.r.t computed time features. External features can also be used along with, or instead of, the computed time features.