Identify which units were truncated

is_unit_truncated() returns a logical vector indicating which observations had their propensity scores modified by truncation. Use is_ps_truncated() to test whether an object has been truncated at all.

The answer comes from the truncation record, which is written for a fixed set of observations and can both be lost and outlive them. On a ps_trunc, vctrs::vec_slice() and c() drop it, and subassignment that grows the vector carries it across a length change; see ps_trunc() for the whole contract. On a psw vector built from truncated propensity scores, a subset drops it, while subassignment that grows the weights carries it across the length change.

is_unit_truncated() therefore checks that the record covers the object it is given, and raises an error of class propensity_missing_meta_error when it does not, or when an object marked as truncated carries no record at all, rather than name truncated units at stale positions. Query the ps_trunc object the record was written for instead.

That check counts observations, which a reordering does not change, so it does not catch one. An operation that reorders through vctrs rather than through [, such as vctrs::vec_slice(x, 5:1) or dplyr::arrange(), keeps a record written for the old order, and a psw keeps one through any same-length operation, a reordering included. is_unit_truncated() answers from those positions and names the wrong units. See ps_trunc() and psw for the whole contract.

Usage

is_unit_truncated(x)

Arguments

x

A ps_trunc object created by ps_trunc(), or a psw vector built from one.

Value

A logical vector the same length as x (or number of rows for matrix input). TRUE marks observations whose values were winsorized.

See also

ps_trunc(), is_ps_truncated(), ps_trunc_meta()

Examples

ps <- c(0.02, 0.3, 0.5, 0.7, 0.98)
ps_t <- ps_trunc(ps, method = "ps", lower = 0.05, upper = 0.95)
is_unit_truncated(ps_t)
#> [1]  TRUE FALSE FALSE FALSE  TRUE