find_ps_rprec_deno.RdCompute the denominator for R-precision based on propensity scored ranking of gold standard labels.
find_ps_rprec_deno(gold_vs_pred, grouping_var, cost_fp)
find_ps_rprec_deno_dplyr(gold_vs_pred, grouping_var, cost_fp)A data.frame with columns "n_gold", "n_suggested", "tp", "fp",
"fn", "delta_relevance", "rprec_deno".
find_ps_rprec_deno_dplyr(): Variant with dplyr based
internals rather than collapse internals.