Dear colleagues, I'm trying (and failing) to write the script required to generate a chart that would help me assess the forecasting accuracy of a logistic regression model by plotting the cumulative proportion of observed events occurring in cases across the range of possible predicted probabilities. In other words, let:
x = any value on 0-1 scale phat_i = predicted probability of event Y from logit model for case i y_i = observed outcome (0/1) for case i Y_cond = sum(y_i) conditional on phat_i <= x Y_tot = total number of events observed in sample What I'm trying to plot is (Y_cond)/(Y_tot) across all values of x. I would be grateful for any guidance you can offer, and I'm sorry if I've overlooked some really simple solution; I'm fairly new to R and learning by doing. Regards, Jay -- Jay Ulfelder, Ph.D. Research Director Political Instability Task Force Science Applications International Corp. (SAIC) jay_ulfel...@stanfordalumni.org (301) 588-8478 [home office] (301) 580-8736 [mobile] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
