Querying a dataframe in R

Question

I have a dataframe which has a 3 fields: NAME, CATEGORY, COUNTRY

Now I would like to have all data where the category is the String over 10 mio or the Country is Germany and the Country is Sweden.

Any recommendation how to "query" my dataFrame in R?

I would appreciate your replies!

Subsetting is part of every basic tutorial. Read some. – Roland Jan 23 '15 at 10:18 — Roland, Jan 23 '15 at 10:18

Fedorenko Kristina · Accepted Answer · 2015-01-23T10:30:55.487

2

You can use which.

desireDf <- df[ which( df$CATEGORY=="over 10 mio" &  (df$COUNTRY=="Germany" | df$COUNTRY=="Sweden" )), ]

Also it works without which:

desireDf <- df[ (df$CATEGORY=="over 10 mio" &  (df$COUNTRY=="Germany" | df$COUNTRY=="Sweden")), ]

edited Jan 23 '15 at 10:30

answered Jan 23 '15 at 10:18

3

There is no need to use `which`. `[` accepts logical values in i. – Roland Jan 23 '15 at 10:19
`|` means AND. What is then a logical OR? – Carol.Kar Jan 23 '15 at 10:26
2

@mrquad, | means OR, & means AND (and so the solution doesn't give you the right answer, it gives you rows with CATEGORY = "over 10 mio" OR COUNTRY="Germany" OR COUNTRY="Sweden") – Cath Jan 23 '15 at 10:28
| means logical OR, & means logical AND. – Fedorenko Kristina Jan 23 '15 at 10:29

1 Answers1