CODEWITHSUNDEEP
regexrgrepl
giac
giac

Reputation: 4299

R - grepl conditions on vector to exclude exact match

I am struggling to properly exclude variables when I use grepl.

Imagine my vector is 

 vec = c("POP MUSIC",  "TOP THE POPS", "POPEYE", "MARY POPPINS")

I want to grepl POP when I visually recognise pop music. In my example I want then to exclude "POPEYE", "MARY POPPINS".

How could I do something like ? And why this line of code does not work ? 

vec[ grepl("POP", vec ) & grepl("^POPEY$", vec ) & grepl("^MARY POPPINS$", vec ) ]

desired results

"POP MUSIC" "TOP THE POPS"

thanks

Upvotes: 1

Views: 562

Answers (1)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626804

You can use the following grep solution:

vec = c("POP MUSIC",  "TOP THE POPS", "POPEYE", "MARY POPPINS") 
grep("(?i)\\bPOPS?\\b", vec, value = TRUE)

See IDEONE demo

The regex (?i)\\bPOPS?\\b matches a whole word POP or POPS in a case-insensitive way (due to (?i)) and if found, the value is returned (due to value=TRUE).

You may need to adjust the regex as per your needs (e.g. (?i)\\bPOP(S|PING)?\\b to also allow popping).

Upvotes: 1

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