Skip to contents

Tolerance specification for numeric comparisons

Source: R/options.R
ks_tol.Rd

Builds a tolerance object consumed by ks_compare(). Two numeric values a and b are considered equal when any of the active rules pass:

Usage

ks_tol(abs = 0, rel = 0, ulp = 0, per_column = NULL)

Arguments

abs

Non-negative absolute tolerance (default 0 — strict equality).

rel

Non-negative relative tolerance, scaled by max(abs(a), abs(b)) (default 0).

ulp

Non-negative integer ULP tolerance. Typical values are 4–16; defaults to 0.

per_column

Optional named list of per-column ks_tol() overrides keyed by base-side column name.

Value

A ks_tol S3 list.

Details

  • abs(a - b) <= abs

  • abs(a - b) <= rel * max(abs(a), abs(b))

  • ulp_distance(a, b) <= ulp — IEEE-754 units in the last place, useful for catching floating-point round-trip noise without false positives on genuine differences.

Per-column overrides may be supplied via per_column, a named list whose names are base-side column names and whose values are themselves the result of ks_tol(). Columns not listed fall back to the top-level abs / rel / ulp.

Examples

ks_tol(abs = 1e-9)
#> <ks_tol> abs = 1e-09, rel = 0, ulp = 0
ks_tol(rel = 1e-6, per_column = list(price = ks_tol(abs = 0.005)))
#> <ks_tol> abs = 0, rel = 1e-06, ulp = 0
#> Per-column overrides for: price
ks_tol(ulp = 4)
#> <ks_tol> abs = 0, rel = 0, ulp = 4