CODEWITHSUNDEEP
r
Lovnlust
Lovnlust

Reputation: 1537

return column index condition on column names

I have a data frame named dat. It has some columns with prefix vix.

Eg.

Date, VO, vix2, vix3, vix4, ... vix24, other columns

In this case,

start = which(names(dat) == "vix2")

end = which(names(dat) == "vix24")

But the problem is, I don't know the number arrangement after vix. In this case, is there a way to return start and end?

Upvotes: 2

Views: 128

Answers (1)

akrun
akrun

Reputation: 887891

You can try

 range(grep('vix', names(dat)))

Suppose if the columns are not consecutive

  v1 <- c('Date',  'vix2',  'v0', 'vix3', 'V5', 'vix4')
  range(grep('vix', v1))
  #[1] 2 6

will give the first and last entry with 'vix', but if you are going to subset the dataset for 'vix' columns, you don't need the range, just grep will be enough

  grep('vix', v1)
 #[1] 2 4 6

Upvotes: 2

Related Questions