create dummy variable from string variable

Question

I am trying to create a dummy variable from a column variable from an existing data set. The variable I am interested in is a title in this format:

CHEMICALS - Commission Delegated Directive (EU) 2015/863 of 31 March 2015 amending Annex II to Directive 2011/65/EU of the European Parliament and of the Council as regards the list of restricted substances (Text with EEA relevance)

or

Commission Implementing Directive (EU) 2015/2392...

I want to create a dummy variable indicating that the Title is either implementing or delegated. In other words, when the word "delegated" is in my title variable, this will be labeled 1 and everything else will be labeled 0.

Can anyone help me with this? It is very appreciated. So far, I have used this code:

infringements$delegated <- ifelse(infringements$Title=="Delegated", 1, 0)
table(infringements$delegated, infringements$Title)  
summary(infringements$delegated)

When I run the code, I get 0 matches, even though I know that there are 41 matches.

You can use str_detect() from the package stringr instead of == because == will only check if your string is equal to "Delegated" and what you're trying to do is to detect a pattern in your title. — Mbr Mbr
Use grepl, i.e. as.integer(grepl('Delegated', infringements$Title)) — Sotos
great, thank you! I used the grepl suggestion because I have already been working with the grep package, and this worked. — reveraert

akrun akrun · Accepted Answer · 2017-03-23T10:19:26

We can do

+(grepl('Delegated', infringements$Title))

create dummy variable from string variable

3 Answers