I am using the dummies package to generate dummy variables for categorical variables, some with more than two categories. testdf<- data.frame( "A" = as.factor(c(1,2,2,3,3,1)), "B" = c('A','B...

I've trained an elastic net model in R using glmnet and would like to use it to make predictions off of a new data set. But I'm having trouble producing the matrix to use as an argument in the pre...

I am having a problem to run glmnet lasso with a wide data set. My data has N=50, but p > 49000, all factors. So to run glmnet i have to create a model.matrix, BUT i just run out of memory when i c...

I have a data table and I want to create a new column for each unique day, and then assign a 1 in each row where the day matches the column name I have done this using a for loop but I was w...

I would like to create a matrix of indicator variables. My initial thought was to use model.matrix, which was also suggested here: Automatically expanding an R factor into a collection of 1/0 indic...