Remove .x from a column

Question

I have a table with first two columns that looks like this:

Human_ortholog  Representative_transcript
FAM126A         ENST00000409923.1
CYP3A5          ENST00000339843.2
LCMT1           ENST00000399069.3
SPATA31A6       ENST00000332857.6

How can I remove the .n where n is the number after ., using gsub?

Answer 1

Here’s how:

df$col = sub('\\.\\d$', '', df$col)

This removes a single digit, preceded by a dot, at the end of the string. If the numbers could consist of multiple digits, use an appropriate quantifier:

df$col = sub('\\.\\d+$', '', df$col)

This answer is using sub since you only want to perform a single replacement per string. gsub makes sense (only) when performing multiple replacements per string, as in this example:

sub('[aeiou]', '', 'This is a test')
# [1] "Ths is a test"
gsub('[aeiou]', '', 'This is a test')
# [1] "Ths s  tst"