why my R^2 is so small while there do seem to be a dependency there?
The model given, ~0 +factor, omitted an intercept. R^2 is meaningless without an intercept. Further discussion should go to a statistics list like stats.stackexchange.com, as these are statistics, not R, issues. Cheers, Bert
On Sun, Aug 4, 2013 at 1:41 PM, Rui Barradas <ruipbarradas at sapo.pt> wrote:
Hello, Hoe did you get 0.002? Can you ?dput your data? d <- read.table(text = " factor observation -0.003 -2 -0.002 -2 -0.001 -1 0.000 1 0.001 0 0.002 1 0.003 2 ", header = TRUE) fit <- lm(observation ~ 0 + factor, data = d) summary(fit) # R2 is 0.8595, not 0.002 Hope this helps, Rui Barradas Em 04-08-2013 18:19, CHEN, Cheng escreveu:
Hi gurus! What I need to do is to find a model, which can predict what the * observation* should look like given a *factor* input. i am doing a simple linear fit in R: lm(observation~0+factor, data=d), the R^2 is 0.002, which is really small. however, when I do a 'SELECT AVG observation by 0.001 BRACKET factor', there result is something like: *factor* | *average observersion* -0.003 -2 -0.002 -2 -0.001 -1 0.000 1 0.001 0 0.002 1 0.003 2 from a user perspective, i definitely see a pattern here, but somehow this pattern is not captured by a linear model. Is my understanding correct? so R gurus, which model do you suggest me to try for such data? Thanks!
______________________________________________ R-help at 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.
Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm