lag_of: Define a lagged feature from variable history

In fluxCore: Probabilistic Simulation of Single-Entity Systems in Irregular Time

Define a lagged feature from variable history

Description

Extract the k-th most recent value of a variable from sparse history as of (j, t).

Usage

lag_of(
  name,
  target,
  k = 1,
  lookback_t = NULL,
  lookback_j = NULL,
  include_current = FALSE,
  force = FALSE,
  na_value = NA,
  clock = "time"
)

Arguments

name	Name of the derived feature.
target	A target created by declare_variable().
k	Positive integer lag order (1 = most recent prior value by default).
lookback_t	Optional numeric lookback window on the time axis. Takes precedence over lookback_j.
lookback_j	Optional integer lookback window in event-index units.
include_current	Logical; include boundary event at t/j (default FALSE).
force	Logical; if TRUE return na_value when insufficient history exists (default FALSE).
na_value	Value to return when force=TRUE and insufficient history exists (default NA).
clock	Which column in entity$events defines the time axis for lookback_t (default "time").

Value

A function (entity, j, t) -> scalar or NULL.

fluxCore documentation built on Sept. 22, 2026, 5:07 p.m.