Also, it's worth pointing out the reason for the numerical instability of the parameter estimates: the predictors are nearly collinear.
> (dubious <- read.table('clipboard')) V1 V2 V3 V4 V5 V6 V7 1 1 300 39.87 39.85 39.90 39.87333 90000 2 2 400 45.16 45.23 45.17 45.18667 160000 3 3 500 50.72 51.03 50.90 50.88333 250000 4 4 600 56.85 56.80 57.02 56.89000 360000 5 5 700 63.01 63.09 63.14 63.08000 490000 6 6 800 69.52 59.68 69.63 66.27667 640000 > round(cor(dubious), 3) V1 V2 V3 V4 V5 V6 V7 V1 1.000 1.000 0.999 0.951 0.999 0.997 0.991 V2 1.000 1.000 0.999 0.951 0.999 0.997 0.991 V3 0.999 0.999 1.000 0.942 1.000 0.995 0.996 V4 0.951 0.951 0.942 1.000 0.943 0.970 0.912 V5 0.999 0.999 1.000 0.943 1.000 0.995 0.995 V6 0.997 0.997 0.995 0.970 0.995 1.000 0.983 V7 0.991 0.991 0.996 0.912 0.995 0.983 1.000 Note that the correlation for V2 and V7 is about .991 Kingsford Jones On Thu, May 15, 2008 at 3:01 PM, e-letter <[EMAIL PROTECTED]> wrote: > Thank you to all you eagle eyes; amendment made accordingly and solved. Not > sure how the difference occurred... > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org 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. > ______________________________________________ R-help@r-project.org 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.