Hi! This is my first time posting. I've read the general rules and guidelines, but please bear with me if I make some fatal error in posting. Anyway, I have a continuous response and 29 predictors made up of continuous variables and nominal and ordinal categorical variables. I'd like to do lasso on these, but I get an error. The way I am using "lars" doesn't allow for the factors. Is there a special option or some other method in order to do lasso with cat. variables?
Here is and example (considering ordinal variables as just nominal): set.seed(1) Y <- rnorm(10,0,1) X1 <- factor(sample(x=LETTERS[1:4], size=10, replace = TRUE)) X2 <- factor(sample(x=LETTERS[5:10], size=10, replace = TRUE)) X3 <- sample(x=30:55, size=10, replace=TRUE) # think age X4 <- rchisq(10, df=4, ncp=0) X <- data.frame(X1,X2,X3,X4) > str(X) 'data.frame': 10 obs. of 4 variables: $ X1: Factor w/ 4 levels "A","B","C","D": 4 1 3 1 2 2 1 2 4 2 $ X2: Factor w/ 5 levels "E","F","G","H",..: 3 4 3 2 5 5 5 1 5 3 $ X3: int 51 46 50 44 43 50 30 42 49 48 $ X4: num 2.86 1.55 1.94 2.45 2.75 ... I'd like to do: obj <- lars(x=X, y=Y, type = "lasso") Instead, what I have been doing is converting all data to continuous but I think this is really bad! XX <- data.matrix(X) obj <- lars(x=XX, y=Y, type = "lasso") Thanks for any consideration, Tina ______________________________________________ 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.
