Thanks, Deepayan! However, for me this has deepened the mystery (I don't really understand in detail how lattice graphics works anyway!).
To clarify: The variables X,Y,Z,W in DF have some zero values, and otherwise are positive. For U,V in X,Y,Z,W I plot log(1+V) against log(1+U) for all the points. But I regress log(V) on log(U) using only those points where both U and V are positive (for these data the difference between log(U) and log(1+U) is small when U>0, and has little effect on the plot; but I want the regression to be as stated). Can this be incorporated into the framework you suggest below? Thanks! Ted. On 04-Sep-03 Deepayan Sarkar wrote: > You can't do it in that sequence, and whether you can do it at all > depends on exactly what you mean when you say that the data used for > the regressions are not the same as those used for the plots. The > typical way would be to do > > splom(DF, > panel = function(x, y, ...) { > panel.xyplot(x, y, ...) > > # modify x and y as appropriate (?) > # whether that can be done depends on whether > # you have all the information you need > # available inside the panel function > > fm <- lm(y ~ x) > panel.abline(fm) > }) > > Can't think of anything else (other than using a custom superpanel > function). > > Deepayan > > On Thursday 04 September 2003 11:47 am, Ted Harding wrote: >> Sorry Folks, >> I'm sure I could suss out the answer myself but I need it >> soon ... ! >> >> 1. Given a set of 4 variables X,Y,Z,W in a dataframe DF, I make >> a scatter-plot matrix using splom(DF). >> >> 2. I do all regressions of U on V using lm(U~V), where U and V >> are all 12 different ordered pairs from X,Y,Z,W. >> >> 3. Now I would like to superpose the regression lines from (2) >> onto the corresponding panels from (1). >> >> (By the way, the data used for the regressions are not quite >> the same as those used for the plots, since a few observations >> are omitted from the regressions but appear on the plots, >> so (1) and (2) really are separate operations). >> >> With thanks, >> Ted. >> >> >> -------------------------------------------------------------------- >> E-Mail: (Ted Harding) <[EMAIL PROTECTED]> >> Fax-to-email: +44 (0)870 167 1972 >> Date: 04-Sep-03 Time: 17:47:39 >> ------------------------------ XFMail ------------------------------ >> >> ______________________________________________ >> [EMAIL PROTECTED] mailing list >> https://www.stat.math.ethz.ch/mailman/listinfo/r-help -------------------------------------------------------------------- E-Mail: (Ted Harding) <[EMAIL PROTECTED]> Fax-to-email: +44 (0)870 167 1972 Date: 05-Sep-03 Time: 01:52:31 ------------------------------ XFMail ------------------------------ ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help