R function to increment numbers at each row-CodePudding

I'm trying to create a new column "ID" in a dataframe.

Each row must have a unique ID incremented by 5 each time. But it should not start at 0, but from a desired number (let's say N = max of another dataset's column).

What would be the easiest way of doing that? (loop? function?)

CodePudding user response：

You can use seq(first_value,step, length.out), so in your case, ID <- seq(N, by = 5, length.out = nrow(data)) with data you actual data. Here's an example with the starting point to 10 (which you can replace with N):

library(dplyr)
iris %>% 
  mutate(ID = seq(10,by = 5,length.out = nrow(iris)))

Output:

  Sepal.Length Sepal.Width Petal.Length Petal.Width Species ID
1          5.1         3.5          1.4         0.2  setosa 10
2          4.9         3.0          1.4         0.2  setosa 15
3          4.7         3.2          1.3         0.2  setosa 20
4          4.6         3.1          1.5         0.2  setosa 25
5          5.0         3.6          1.4         0.2  setosa 30
6          5.4         3.9          1.7         0.4  setosa 35
...