These functions are called internally by get_cumulative and
should usually not be called directly.
make_time_mat(data, nz)make_latency_mat(data, tz)
make_lag_lead_mat(data, tz, ll_fun = function(t, tz) t >= tz)
make_z_mat(data, z_var, nz, ...)
A data set (or similar) from which meta information on cut-points, interval-specific time, covariates etc. can be obtained.
Which should be transformed into functional covariate format
suitable to fit cumulative effects in mgcv::gam.