How to create a series of descending string in a column in data frame in R

Question

[Mohamed Samir]

Dear , I would like to create a new column in a data frame in R, where I want to have string (e.g. SNP) in a descending orders (e.g. SNPs1, SNPs2, SNPs3, etc.). Could any of you let me know how ?

[Basti]

It is difficult to see what you need without an example, you may have a look at the arrange() function : https://dplyr.tidyverse.org/reference/arrange.html

[Mohamed Samir]

Thanks. Actually, this link is not what I am looking for. I want to create a new column, and I want to have value in this column that are n a descending orders (e.g. SNPs1, SNPs2, SNPs3, etc.). Example: my data frame is DF, and I want it to have a new column (here is columnX), and it should contain the characters SNP1, SNP2, SNP3, etc. like this table :

[Basti]

Ok, please next time directly add a reproducible example in your post to make your question clear to others

Answer 1

[zx8754]

We need paste:

# example data
d <- data.frame(rn = 1:3)
# d
#   rn
# 1  1
# 2  2
# 3  3

d$ColumnX <- paste0("SNP", seq_len(nrow(d)))
# d
#   rn ColumnX
# 1  1    SNP1
# 2  2    SNP2
# 3  3    SNP3

[Mohamed Samir]

Thank you, this is exactly what I need