Setting a formula for GLM as a sum of columns in R

Question

I am trying to set the formula for GLM as the ensemble of columns in train - train$1:99:

model <- glm(train$100 ~ t         


        

Answer 1

The simplest way, assuming that you want to use all but column 100 as predictor variables, is

 model <- glm(v100 ~. , data = train, family = "binomial")

where v100 is the name of the 100th column (the name can't be 100 unless you have done something advanced/sneaky to subvert R's rules about data frame column names ...)

Answer 2

If you need outcome ~ var1 + var2 + ... + varN, then try this:

# Name of the outcome column
f1 <- colnames(train)[100]

# Other columns seperated by "+"
f2 <- paste(colnames(train)[1:99], collapse = "+")

#glm
model <- glm(formula = as.formula(paste(f1, f2, sep = "~")),
             data = train,
             family = "binomial")