Help with lm and multiple linear regression? (Plain Text version)
consider merging everything into a singe dataframe. i haven't tried it, but something like the following could work:
reg.data <- cbind(margin, personcoeff)
names(reg.data) <- c('margin', 'p1', 'p2')
lm(margin~p1+p2, data = reg.data)
the idea here is that by specifying the data frame with the data argument in lm, R looks for the columns of the names specified in the formula. for weights, see ?lm and look for the weights argument. cheers, tc
On Dec 28, 2007 10:22 AM, Aaron Barzilai <aaron_barzilai at yahoo.com> wrote:
(Apologies the previous version was sent as rich text) Hello, I'm new to R, but I've read the intro to R and successfully connected it to an instance of mysql. I'm trying to perform multiple linear regression, but I'm having trouble using the lm function. To start, I have read in a simply y matrix of values(dependent variable) and x matrix of independent variables. It says both are data frames, but lm is giving me an error that my y variable is a list. Any suggestions on how to do this? It's not clear to me what the problem is as they're both data frames. My actual problem will use a much wider matrix of coefficients, I've only included two for illustration. Additionally, I'd actually like to weight the observations. How would I go about doing that? I also have that as a separate column vector. Thanks, Aaron Here's my session:
margin
margin 1 66.67 2 -58.33 3 100.00 4 -33.33 5 200.00 6 -83.33 7 -100.00 8 0.00 9 100.00 10 -18.18 11 -55.36 12 -125.00 13 -33.33 14 -200.00 15 0.00 16 -100.00 17 75.00 18 0.00 19 -200.00 20 35.71 21 100.00 22 50.00 23 -86.67 24 165.00
personcoeff
Person1 Person2 1 -1 1 2 -1 1 3 -1 1 4 -1 1 5 -1 1 6 -1 1 7 0 0 8 0 0 9 0 1 10 -1 1 11 -1 1 12 -1 1 13 -1 1 14 -1 0 15 0 0 16 0 0 17 0 1 18 -1 1 19 -1 1 20 -1 1 21 -1 1 22 -1 1 23 -1 1 24 -1 1
class(margin)
[1] "data.frame"
class(personcoeff)
[1] "data.frame"
lm(margin~personcoeff)
Error in model.frame(formula, rownames, variables, varnames, extras, extranames, :
invalid type (list) for variable 'margin'
____________________________________________________________________________________ Be a better friend, newshound, and ______________________________________________ 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.
Tim Calkins 0406 753 997