as.data.frame.SCREENING: Coerce a 'SCREENING' object to a data frame
Description
Returns a tidy data.frame with one row per fund (or, when
the screening was run with screen_beta = TRUE, one row per
fund/coefficient), suitable for downstream filtering, ranking, and plotting.
A data.frame with columns fund, the performance measure
(alpha, sharpe, or msharpe), pipos, pizero,
pineg, npeer, and lambda; a coefficient column is
added when screen_beta = TRUE.