Returns the noise magnitudes used by classify_with_uncertainty
for a cell of the given evidence grade. A measurement (grade A) is
perturbed only slightly; a user-assumed value (grade E) is perturbed
heavily, reflecting how little is actually known about it.
Usage
get_perturbation_scale(grade = c("A", "B", "C", "D", "E"))
Arguments
- grade
One of "A" (measured), "B" (spectra-predicted),
"C" (prior-inferred), "D" (VLM-extracted) or
"E" (user-assumed).
Value
A list with three elements: pct (the half-width of the
multiplicative perturbation, applied to most numeric attributes),
ph_abs (the half-width of the additive perturbation applied
to pH columns) and munsell_abs (the additive half-width for
Munsell value / chroma columns).
Examples
get_perturbation_scale("A")$pct # 0.03 -- measured values barely move
#> [1] 0.03
get_perturbation_scale("E")$pct # 0.30 -- assumptions move a lot
#> [1] 0.3
