How to subset String object in R

Question

I have an AAString () object like below, how can I subset for multiple positions?

df <- AAString("HAKTKIDLTBI")
df

11-letter AAString object
seq: HAKTKIDLTBI

I want to subset for :

substring(df,c(1,3,4,10))

Output:

seq: HKTB

Answer 1

You can use standard indices

df <- AAString("HAKTKIDLTBI")
df[c(1,3,4,10)]
##  4-letter AAString object
##  seq: HKTB

Answer 2

I am not sure if the approach applies to AAString object, but you can have a try

> s <- "HAKTKIDLTBI"

> idx <- c(1, 3, 4, 10)

> paste0(substring(s, idx, idx), collapse = "")
[1] "HKTB"