CODEWITHSUNDEEP
r
Lovnlust
Lovnlust

Reputation: 1537

return most common prefix in columns

If some columns in a data frame share a common prefix, how to I find out such common prefix?

Note: prefix here means the longest substring before any number appears.

data set may look like:

Date,vix1,vix2,vix3,doSG124,doSG220

In this case, I want to get vix instead of doSG because more columns (3) have vix as prefix.

Upvotes: 1

Views: 94

Answers (1)

akrun
akrun

Reputation: 887213

You could try table and which.max after removing the 'suffix' part with sub. Here, I assume that the suffix is the numeric part.

tbl <- table(sub('\\d+$', '', v1))
names(which.max(tbl))
#[1] "vix"

By using sub, we match the numeric part (\\d+) to the end of the string ($) and replace it with ''

data

 v1 <- c('Date', 'vix1', 'vix2', 'vix3', 'doSG124', 'doSG220')

Upvotes: 2

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