flatten_predictors function

Flattens predictor variable data into one row per person

Assumes that splitting explanatory variables do not vary with time. Spline Tree is not meant to handle time-varying covariates.

flatten_predictors(idvar, data)

Arguments

• idvar: The string name of the ID variable (used to group observations)
• data: The full dataset to be flattened (long form)

Returns

A wide format dataset with spline coefficients as the responses.