Thank you, Gavin. I think that might be what I need. But I'm a little bit wandering what's the scale of resid(mod). Is it scale(dist)/scale(speed), for example kilometer / (kilometer per hour)? or something else?
Thank you very much! Wei-Wei 2006/7/12, Gavin Simpson <[EMAIL PROTECTED]>: > 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
