posc - Probability of Outcome Superiority Curves

Computes, plots and compares probability of outcome superiority curves (POSCs). For two people who differ by a given amount on a continuous predictor, a POSC gives the probability that the person with the higher predictor score also has the higher outcome, a probabilistic and decision-oriented alternative to reporting a correlation coefficient. Curves can be computed from a correlation under bivariate normality, from a correlation matrix for an optimally weighted composite of predictors, from a fitted linear model, or estimated directly from raw data with a flexible spline model and bootstrap confidence bands.