Error: invalid type(list) for variable when using lm()
Inline below. -- Bert
On Fri, Nov 25, 2011 at 2:31 AM, Milan Bouchet-Valat <nalimilan at club.fr> wrote:
Le vendredi 25 novembre 2011 ? 00:02 -0800, Dhaynes a ?crit :
Hello, I am new to R. I have multidimensional array (379,2,3) and I need to create a series of linear regressions (379 to be exact) I have the array stored properly I believe, but I can not use the lm(myarray[1,1,1:3]~myarray[1,2,1:3]) I have checked to make sure they are exactly the same length. I have also tried endlessly to convert the subset of the array back into a vector.
?as.vector Actually an array **is** a vector -- but with an additional "dim" attribute. Try:
str(x)
any help would be appreciated.
1) Read relevant portions of R docs, like ?array and perhaps "An Introduction to R." 2) Read and follow the posting guide. In particular, give us a toy example with the code you used to construct your array. It's difficult to diagnose the source of engine failure without the car. 3) See my comment below.
The 'formula' argument of lm doesn't take actual values, but variable names. So you need to create vectors containing your data, or pass a
--This is patently false. Please check before giving obviously wrong advice:
x <- array(rnorm(150), dim= c(10,5,3)) lm(x[,3,2] ~x[,1,1])
Call:
lm(formula = x[, 3, 2] ~ x[, 1, 1])
Coefficients:
(Intercept) x[, 1, 1]
-0.1247 0.1171
data frame with these vectors are columns. So, going the latter way : df <- data.frame(a=myarray[1,1,1:3], b=myarray[1,2,1:3]) lm(a ~ b, data=df) or in one step lm(a ~ b, data=data.frame(a=myarray[1,1,1:3], b=myarray[1,2,1:3])) Regards
______________________________________________ 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