How to change an ff vector to a normal vector R

Question

I have a function that accepts vectors as inputs.

I have an ffdf named X, and would like to use columns of data as vectors for the function inputs.

To take a column of data named "Mag" as a vector I would use the following:

X[['Mag']]

However this is an ff vector I believe and the function will only accept a normal vector, how do I change this back to a normal vector?

I think I need to use just the physical components but I am not sure how to code this.

Thanks in advance.

Answer 1

You can just add [] at the end.

X <- as.ffdf(data.frame(Mag = 1:10))
class(X[["Mag"]])      # ff_vector" "ff" 
class(X[["Mag"]][])    # "integer"

# X[, 'Mag'] also works as jbaums suggested
class(X[, 'Mag'])

# as.vector doesn't work
class(as.vector(X[["Mag"]])) # ff_vector" "ff"