Time Series Forecasting, Fourier, Ensemble Method, Data Science, Signal Processing.
data frame may have columns including: trend features, representing the broad variations of the time series; these could be: a constant term (the value 1 repeated for each row), a function linear in time (literally the enumeration: 0, 1, 2, 3, …), a quadratic function (0, 1, 4, 9, …), a cubic, or