derive: Define a derived feature
In fluxCore: Probabilistic Simulation of Single-Entity Systems in Irregular Time

derive

R Documentation

Define a derived feature

Description

derive() returns a function computing a history-derived feature as of (j, t). Intended to populate Entity$derived_vars and be used by Entity$snapshot*().

Usage

derive(
  name,
  target,
  lookback_t = NULL,
  lookback_j = NULL,
  fn = c("count", "min", "max", "mean", "median", "sd", "iqr", "any", "all"),
  include_current = TRUE,
  force = FALSE,
  na_value = NA,
  clock = "time"
)

Arguments

`name`	Name of the derived feature.
`target`	A target created by event() or declare_variable().
`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.
`fn`	Summary function name. For event() targets, only count, any, and all are supported.
`include_current`	Logical; include the boundary event at t/j (default TRUE).
`force`	Logical; if TRUE, return a value when there is no history (default FALSE).
`na_value`	Value to return when force=TRUE and no history exists (default NA).
`clock`	Which column in entity$events defines the time axis for lookback_t (default "time").