R transform a factor ID variable into a numeric ID variable

Question

I have a programming doubt in R and I have no idea how to solve it after spending hours looking at potential responses on the internet and on Stack Overflow.

I have

Answer 1

In case, the levels are in different order, we can convert the column to factor with levels specified as the unique elements in that column, and then coerce it to numeric/integer.

df1$Numericcolumnname <- as.numeric(factor(df1$Columnname, 
                  levels=unique(df1$Columnname)))