Dear Michael, How about the following?
y <- model.response(model.frame(base.mod)) TSS <- sum((y - mean(y))^2) 1 - drop.mod$RSS/TSS I hope this helps, John > -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of Michael Friendly > Sent: April-02-09 5:39 PM > To: R-Help > Subject: [R] calculating drop1 R^2s > > This is probably simple, but I just can't see it... > > I want to calculate the R^2s for a series of linear models where each > term is dropped in turn. I can get the > RSS from drop1(), and the r.squared from summary() for a given model, > but don't know how to use the > result of drop1() to get the r.squared for each model with one term dropped. > > Working example: > > library(vcd) # for Baseball > library(car) # for vif/recode > data(Baseball) > > # sal87 appears as a factor because missing is coded as '.' rather than NA > Baseball$sal87 <- as.numeric(recode(Baseball$sal87, "'.'=NA")) > Baseball$logsal <- log(Baseball$sal87) > > base.mod <- lm(logsal ~ years+atbat+hits+homeruns+runs+rbi+walks, > data=Baseball) > vif(base.mod) > (drop.mod <- drop1(base.mod)) > > Single term deletions > > Model: > logsal ~ years + atbat + hits + homeruns + runs + rbi + walks > Df Sum of Sq RSS AIC > <none> 124.612 -180.447 > years 1 0.010 124.622 -182.426 > atbat 1 0.570 125.182 -181.247 > hits 1 0.256 124.869 -181.906 > homeruns 1 0.001 124.613 -182.445 > runs 1 0.691 125.303 -180.993 > rbi 1 0.091 124.704 -182.254 > walks 1 0.408 125.020 -181.588 > > > -- > Michael Friendly Email: friendly AT yorku DOT ca > Professor, Psychology Dept. > York University Voice: 416 736-5115 x66249 Fax: 416 736-5814 > 4700 Keele Street http://www.math.yorku.ca/SCS/friendly.html > Toronto, ONT M3J 1P3 CANADA > > ______________________________________________ > [email protected] 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. ______________________________________________ [email protected] 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.
