[R] linear regression in a data.frame using recast
I have a very large dataset with columns of id number, actual value, predicted value. This used to be a time series but I have dropped the time component. So I now have a data.frame where the id number is repeated but each value in the actual and predicted columns are unique. I assume I need to use recast somehow but I'm at a loss... how can I perform a simple linear regression (using lm()?) on my two variables for each unique id number? additionally, I need to fix the y-intercept at zero. Thanks for your help, Justin __ 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.
Re: [R] linear regression in a data.frame using recast
On Mar 16, 2011, at 3:19 PM, Justin Haynes wrote: I have a very large dataset with columns of id number, actual value, predicted value. This used to be a time series but I have dropped the time component. So I now have a data.frame where the id number is repeated but each value in the actual and predicted columns are unique. I assume I need to use recast somehow but I'm at a loss... how can I perform a simple linear regression (using lm()?) on my two variables for each unique id number? additionally, I need to fix the y-intercept at zero. ?formula Something like: lm(y ~ x + factor(id) -1, data=dat) If this is really a time series, then you will have serious validity problems due to auto-correlation among non-independent units. (But if you are just searching for a way to pull the wool over the eyes of the statistically uninformed, then I guess there's no stopping you.) -- David Winsemius, MD West Hartford, CT __ 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.
Re: [R] linear regression in a data.frame using recast -- A fortunes candidate??
Ha! -- A fortunes candidate? -- Bert If this is really a time series, then you will have serious validity problems due to auto-correlation among non-independent units. (But if you are just searching for a way to pull the wool over the eyes of the statistically uninformed, then I guess there's no stopping you.) -- David Winsemius, MD West Hartford, CT __ 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.
Re: [R] linear regression in a data.frame using recast -- A fortunes candidate??
Seconded On 03/16/2011 05:37 PM, Bert Gunter wrote: Ha! -- A fortunes candidate? -- Bert If this is really a time series, then you will have serious validity problems due to auto-correlation among non-independent units. (But if you are just searching for a way to pull the wool over the eyes of the statistically uninformed, then I guess there's no stopping you.) -- David Winsemius, MD West Hartford, CT __ 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.
