On Tue, 2006-07-11 at 23:51 +0800, Guo Wei-Wei wrote: > Dear all, > > I don't know what's my question is called. I have a performance > variable A, such as sales. And I have another variable B, let's say > establish time of firm. I want to create the third variable that is > sales without the effect of establish time. Maybe it can be called > partial effect problem. I'm not sure. > > Does anyone have any suggestion? Thank you in advance! > > All the best, > Wei-Wei
Do you mean? ## dummy data A <- rnorm(100) B <- rnorm(100) C <- resid(lm(A ~ B)) C now contains the residual variation in A after fitting B. e.g. with some real data ?cars data(cars) # not sure this is needed now, I forget mod <- lm(dist ~ speed, data = cars) summary(mod) partial <- resid(mod) ## check mod2 <- lm(dist ~ partial, data = cars) summary(mod2) ## from the two R^2 form mod1 and mod2 - partial contains dist minus ## the effects of speed > 0.6511 + 0.3489 [1] 1 HTH G -- %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% Gavin Simpson [t] +44 (0)20 7679 0522 ECRC & ENSIS, UCL Geography, [f] +44 (0)20 7679 0565 Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk Gower Street, London [w] http://www.ucl.ac.uk/~ucfagls/cv/ London, UK. WC1E 6BT. [w] http://www.ucl.ac.uk/~ucfagls/ %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% ______________________________________________ [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
