How to create a new variable based on characters/text in another variable?

Question

I am a beginner in need of some guidance.

I have a data frame that looks like the following (simplified example w. two columns, was imported from a CSV):

Price | Features
100 | {TV, wifi}
125 | {TV, wifi, "Air conditioning"}
110 | {wifi, "Wheelchair accessible", Sauna}

What I would like to do in this example is create a new column called "TV". This column would indicate TRUE if TV is listed as a feature, and FALSE if TV is not listed.

Price | Features | TV
100 | {TV, wifi} | TRUE
125 | {TV, wifi, "Air conditioning"} | TRUE
110 | {wifi, "Wheelchair accessible", Elevator} | FALSE

I have googled and found examples of how to do this based on conditions (if x = TRUE or x > 0) but I'm unclear how to do it when I am looking for characters/phrases present in a variable.

score 0 · Answer 1 · answered Apr 19 '19 at 18:19

You could try pattern matching like so with grepl:

tvs <- data.frame(
  Price = c(100, 125, 110),
  Features = c(
    '{TV, wifi}',
    '{TV, wifi, "Air conditioning"}',
    '{wifi, "Wheelchair accessible", Sauna}'
  ),
  stringsAsFactors = FALSE
)

tvs$TV <- grepl("TV", tvs$Features, fixed = TRUE)

So now tvs is:

  Price                               Features    TV
1   100                             {TV, wifi}  TRUE
2   125         {TV, wifi, "Air conditioning"}  TRUE
3   110 {wifi, "Wheelchair accessible", Sauna} FALSE

How to create a new variable based on characters/text in another variable?

1 Answers1