I have the following data frame in R:
> str(df)
'data.frame': 545227 obs. of 15 variables:
$ ykod : int 93 93 93 93 93 93 93 93 93 93 ...
$ yad : Factor w/ 42 levels "BAKUGAN","BARBIE",..: 30 30 30 30 30 30 30 30 30 30 ...
$ per : Factor w/ 3 levels "2 AYLIK","3 AYLIK",..: 3 3 3 3 3 3 3 3 3 3 ...
$ donem: int 201101 201101 201101 201101 201101 201101 201101 201101 201101 201101 ...
$ sayi : int 201101 201101 201101 201101 201101 201101 201101 201101 201101 201101 ...
$ mkod : int 4 5 9 11 12 18 20 22 25 26 ...
$ mad : Factor w/ 10464 levels " Defne Market ",..: 405 8075 9710 10145 9297 7973 2542 3892 2759 5769 ...
$ mtip : Factor w/ 29 levels "Abone Bürosu ",..: 2 20 20 2 2 2 2 2 2 2 ...
$ kanal: Factor w/ 2 levels "OB","SS": 2 2 2 2 2 2 2 2 2 2 ...
$ bkod : int 110565 110565 110565 110565 110565 110565 110565 110565 110565 110565 ...
$ bad : Factor w/ 212 levels "4. Levent","500 Evler",..: 167 167 167 167 167 167 167 167 167 167 ...
$ bolge: Factor w/ 12 levels "Adana Şehiriçi",..: 7 7 7 7 7 7 7 7 7 7 ...
$ sevk : int 2 3 3 3 2 2 2 6 2 2 ...
$ iade : int 2 1 0 2 0 2 1 0 0 2 ...
$ satis: int 0 2 3 1 2 0 1 6 2 0 ...
I want to list unique (like SQL's DISTINCT) values for selected multiple variables. For example, unique(yad) gives me the names of each 42 elements, but I need to extract two columns (yad and per together, with all unique combinations):
yad per
--- ---
BARBIE AYLIK
BAKUGAN 2 AYLIK
MICKEY MOUSE 2 AYLIK
TINKERBELL 3 AYLIK
... ...
How can I achieve this?
How about using unique() itself?
df <- data.frame(yad = c("BARBIE", "BARBIE", "BAKUGAN", "BAKUGAN"),
per = c("AYLIK", "AYLIK", "2 AYLIK", "2 AYLIK"),
hmm = 1:4)
df
# yad per hmm
# 1 BARBIE AYLIK 1
# 2 BARBIE AYLIK 2
# 3 BAKUGAN 2 AYLIK 3
# 4 BAKUGAN 2 AYLIK 4
unique(df[c("yad", "per")])
# yad per
# 1 BARBIE AYLIK
# 3 BAKUGAN 2 AYLIK