search for: c_influence

...8> > <environment: namespace:stats> > which is not very helpful] influence.lm is just saying you should be looking at lm.influence #Try typing: lm.influence Admittedly the meat of that function is probably encapsulated in C with the results delivered by: res <- .Call(C_influence, mqr, do.coef, e, tol) Perhaps looking at: https://svn.r-project.org/R/trunk/src/library/stats/src/influence.c I haven't been following the rest of the thread so this is just commenting on your difficulties reading R code. -- David. > > ________________________________________ &...

...>> which is not very helpful] > > influence.lm is just saying you should be looking at lm.influence > > #Try typing: > lm.influence > > Admittedly the meat of that function is probably encapsulated in C with the results delivered by: > > res <- .Call(C_influence, mqr, do.coef, e, tol) > > Perhaps looking at: > > https://svn.r-project.org/R/trunk/src/library/stats/src/influence.c > > > I haven't been following the rest of the thread so this is just commenting on your difficulties reading R code. When I do attempt filling in bla...

Martin - Thanks, but although hatvalues() is useful for calculating PRESS, I can't find anything directly relevant to my question in the influence help pages. After some burrowing in the literature I'm doubting there is an answer out there (PRESS R^2 is always presented in a fairly ad hoc way). This is a new topic, as you say, and perhaps better handled on a statistics list. Murray Efford

>>>>> Murray Efford <murray.efford at otago.ac.nz> >>>>> on Fri, 8 Apr 2016 18:45:33 +0000 writes: > Thanks for these perfectly consistent replies - I didn't > understand the purpose of m = sum(w * f/sum(w)) and saw it > merely as a weighted average of the fitted values. My > ultimate concern is how to compute an appropriate