Store values from different variables in one variable-CodePudding

I am using a dataset that stores country-specific information in different variables, I want to combine this into a single variable. It feels like this should be such an easy exercise, but I cannot figure it out and I can't find any answers here.

Say the data looks like this:

df <- data.frame(country = c("BE", "BE", "BE", "NL", "NL", "NL"),
                 year = c(2010, 2010, 2010, 2010, 2010, 2010),
                 party_NL = c(NA, NA, NA, "A", "B", "B"),
                 party_BE = c("C", "D", "E", NA, NA, NA))

  country year party_NL party_BE
1      BE 2010     <NA>        C
2      BE 2010     <NA>        D
3      BE 2010     <NA>        E
4      NL 2010        A     <NA>
5      NL 2010        B     <NA>
6      NL 2010        B     <NA>

What I need is the following:

  country year party_NL party_BE party
1      BE 2010     <NA>        C     C
2      BE 2010     <NA>        D     D
3      BE 2010     <NA>        E     E
4      NL 2010        A     <NA>     A
5      NL 2010        B     <NA>     B
6      NL 2010        B     <NA>     B

Guessing some loop would have to be applied. Once again, it sounds so easy that I apologize in advance.

Thanks

CodePudding user response：

You can use coalesce in dplyr:

df %>% 
  mutate(party = coalesce(party_NL, party_BE))

Output:

  country year party_NL party_BE party
1      BE 2010     <NA>        C     C
2      BE 2010     <NA>        D     D
3      BE 2010     <NA>        E     E
4      NL 2010        A     <NA>     A
5      NL 2010        B     <NA>     B
6      NL 2010        B     <NA>     B

CodePudding user response：

Use mutate from dplyr, this will do the trick:

require(dplyr)
df %>% 
  mutate(party = ifelse(is.na(party_NL), party_BE, party_NL))