FDA-Aware Grouping Function for SelectBoost — make_functional_grouping

Builds a closure that can be passed directly to group= in SelectBoost::fastboost() or SelectBoost::autoboost(). The returned grouping function respects functional block boundaries and can optionally restrict groups to local neighborhoods along the observation grid.

Usage

make_functional_grouping_function(
  x,
  association = NULL,
  method = c("threshold", "community"),
  association_method = c("correlation", "neighborhood", "hybrid", "interval"),
  within_blocks = TRUE,
  bandwidth = NULL,
  interval_groups = NULL,
  width = NULL,
  step = width,
  decay = 1
)

Arguments

x: Any input accepted by as_functional_matrix().
association: Optional square association matrix. When omitted, the correlation matrix supplied by SelectBoost is reused after applying the FDA-specific masks.
method: Grouping strategy. "threshold" wraps SelectBoost::group_func_1() and "community" wraps SelectBoost::group_func_2().
association_method: Association structure passed to functional_association().
within_blocks: Should groups be restricted to features coming from the same functional block?
bandwidth: Optional maximum within-block lag retained in groups.
interval_groups, width, step, decay: Additional arguments passed to functional_association() when using region-aware associations.

Value

A function with signature (absXcor, c0) compatible with SelectBoost.