insert the same string into multiple rows in a single column

Question

I have an R data frame that looks like this :

I would like to insert the same string into specific rows and into one column, like this (image 2):

e.g. String 'zoo' into a single column 'groups' in only rows 1 ,3 and 6

When asking for help, it's easier if you include data in a [reproducible format](https://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example) rather than putting data inside images. — MrFlick, Feb 01 '20 at 06:05

score 2 · Answer 1 · answered Feb 01 '20 at 05:53

You may try:

df[df$RowNumber %in% c(1,3,6), "groups"] <- "zoo"
df

RowNumber groups
1         1    zoo
2         2   <NA>
3         3    zoo
4         4   <NA>
5         5   <NA>
6         6    zoo
7         7   <NA>

Data:

df <- data.frame(RowNumber=c(1:7), groups=rep(NA,7))

score 0 · Answer 2 · answered Feb 01 '20 at 11:25

Re-using @Tim Biegeleisen's data, you could use the ifelse function to define the condition under which the values in column groupsshould change to zoo:

df$groups <- ifelse(df$RowNumber==1|df$RowNumber==3|df$RowNumber==6, "zoo", df$groups); df
  RowNumber groups
1         1    zoo
2         2   <NA>
3         3    zoo
4         4   <NA>
5         5   <NA>
6         6    zoo
7         7   <NA>

insert the same string into multiple rows in a single column

2 Answers2