Re: [R] question about linear regression and leverage

2011-06-21 Thread Bert Gunter
You really really need to consult with a local statistician for help. You are making a valiant effort, but it is clear that you have insufficient background and experience. Get help from an expert if you can. It is no dishonor, you will learn a lot, and you will avoid incorrect conclusions. Cheers

Re: [R] question about linear regression and leverage

2011-06-21 Thread George Markomanolis
Dear David, Thanks for your answer. Yes now that you mentioned these points are in the beginning of a variable range. From the plot of the residuals seems to have non constant variance which is solved by a transformation. I checked also for interactions by using the symbol : between two variables

Re: [R] question about linear regression and leverage

2011-06-21 Thread David Winsemius
On Jun 21, 2011, at 3:49 AM, George Markomanolis wrote: Dear all, I am new to this field and I have a question about a linear regression. I have a dataset of around to 31000 points and I want to apply a linear regression. The R-squared is 0.9 however when I check the diagnostic plots I ca

[R] question about linear regression and leverage

2011-06-21 Thread George Markomanolis
Dear all, I am new to this field and I have a question about a linear regression. I have a dataset of around to 31000 points and I want to apply a linear regression. The R-squared is 0.9 however when I check the diagnostic plots I can see that there are around to 250 points with big leverage value