Test whether the weights themselves have been truncated

is_wt_truncated() returns TRUE for a psw vector whose own values were bounded, and is_unit_wt_truncated() returns which of its weights the bound moved.

Truncating the weights is recorded apart from truncating the propensity scores they were built from, which is_ps_truncated() and is_unit_truncated() report. The two are different operations, and a set of weights can carry either, both, or neither.

Usage

is_wt_truncated(x)

is_unit_wt_truncated(x)

Arguments

x: An object. is_unit_wt_truncated() accepts only a psw vector.

Value

is_wt_truncated(): a single TRUE or FALSE. It is FALSE for anything that is not a psw vector.
is_unit_wt_truncated(): a logical vector the same length as x, TRUE for each weight the bound moved.

Details

The truncation leaves a record on the weights, the psw_trunc_meta attribute, holding the method, the bound as given and as applied, and the positions of the weights it moved. is_unit_wt_truncated() answers from those positions, so the record follows the rules psw describes for the records a modified propensity score leaves: it is kept through arithmetic and subassignment, re-indexed through the subscript of [, and loses its positions to any other slice and to a combine, which keeps the method and bounds. The wt_truncated flag describes the weights as a whole and is kept through all of those, so is_wt_truncated() keeps its answer where is_unit_wt_truncated() has none to give.

is_unit_wt_truncated() therefore checks that the record covers the weights it is given, and raises an error of class propensity_missing_meta_error when it does not, or when weights marked as truncated carry no record at all, rather than name truncated weights at stale positions. Weights that were not truncated have no record to read, and every weight is reported as untouched.

Examples

w <- psw(c(1.2, 0.8, 1.5), estimand = "ate")
is_wt_truncated(w)
#> [1] FALSE
is_unit_wt_truncated(w)
#> [1] FALSE FALSE FALSE