CODEWITHSUNDEEP
rdataframedplyr
Danby
Danby

Reputation: 108

How do I repeat a string in a data.frame column n times

I'm trying to do the following in dplyr:

If I had a dataframe with sequences (df) and wanted to repeat the sequences in each row by n times (df2), how can I get a table that can do this in dplyr (answer = df2)? Thanks in advance! 

df <- data.frame(start = c("ATG", "ATG", "ATG"), 
                 seq = c("AAACCCTTT", "AAACCCTTT", "AAACCCTTT"), 
                 stop = c("TAG", "TAG", "TAG"))

df1 <- data.frame(n = c("1", "2", "3"))

df2 <- data.frame(start = c("ATG", "ATGATG", "ATGATGATG"), 
                  seq = c("AAACCCTTT", "AAACCCTTTAAACCCTTT", "AAACCCTTTAAACCCTTTAAACCCTTT"), 
                  stop = c("TAG", "TAGTAG", "TAGTAGTAG"))

Upvotes: 1

Views: 667

Answers (3)

akrun
akrun

Reputation: 887118

Using mutate with across

library(dplyr)
df %>% 
     mutate(across(everything(), ~ strrep(., df1$n)))

Upvotes: 1

s_baldur
s_baldur

Reputation: 33488

Base R:

df2 <- df
df2[] <- mapply(strrep, df, df1)
df2

      start                         seq      stop
1       ATG                   AAACCCTTT       TAG
2    ATGATG          AAACCCTTTAAACCCTTT    TAGTAG
3 ATGATGATG AAACCCTTTAAACCCTTTAAACCCTTT TAGTAGTAG

Upvotes: 2

Erich Neuwirth
Erich Neuwirth

Reputation: 1031

df <- data.frame(start = c("ATG", "ATG", "ATG"), 
                 seq = c("AAACCCTTT", "AAACCCTTT", "AAACCCTTT"), 
                 stop = c("TAG", "TAG", "TAG"))

df1 <- data.frame(n=1:3)

df2 <-
  df %>%
  bind_cols(df1) %>%
  mutate_at(vars(start:stop),~strrep(.,n))

df2

Upvotes: 2

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