Batch convert columns to numeric type

Question

I have a dataframe with a bunch of columns that I need to convert to the numeric type. I have written the following code to try to do this, however it is saying the replacem

Answer 1

As SenorO pointed out, the reason your original code does not work is that $i will not evaluate i to find out it's current value. You should instead access and assign to the column using double brackets, which work when i is a name or index number:

for (i in instanceconvert)
{
  regmodel[[i]] <- as.numeric(regmodel[[i]])
}

Following Ari's approach, you can get rid of the loop:

regmodel[,instanceconvert] <- 
    lapply(regmodel[,instanceconvert,drop=FALSE],as.numeric)

You could also do this with your range, 7:262, in place of "instanceconvert", since you can access/assign by name or column number.