5 messages · ikuzar, Rainer Schuermann, R. Michael Weylandt
Hi,
I 'd like to know how to retrieve a column name of a data frame. For
instance :
df = data.frame(c1=c('a','b'),c2=c(1,2))
df
c1 c2 1 a 1 2 b 2 I would like to retrieve the column name which value is 2 (here, the column is c2) thanks for your help -- View this message in context: http://r.789695.n4.nabble.com/How-to-retrieve-a-column-name-of-a-data-frame-tp4351764p4351764.html Sent from the R help mailing list archive at Nabble.com.
colnames(df)[2] Michael
Hi,
I 'd like to know how to retrieve a column name of a data frame. For
instance :
df = data.frame(c1=c('a','b'),c2=c(1,2))
df
?c1 c2 1 ?a ?1 2 ?b ?2 I would like to retrieve the column name which value is 2 (here, the column is c2) thanks for your help -- View this message in context: http://r.789695.n4.nabble.com/How-to-retrieve-a-column-name-of-a-data-frame-tp4351764p4351764.html Sent from the R help mailing list archive at Nabble.com.
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
colnames( df )[2]
[1] "c2"
Hi,
I 'd like to know how to retrieve a column name of a data frame. For
instance :
df = data.frame(c1=c('a','b'),c2=c(1,2))
df
c1 c2 1 a 1 2 b 2 I would like to retrieve the column name which value is 2 (here, the column is c2) thanks for your help -- View this message in context: http://r.789695.n4.nabble.com/How-to-retrieve-a-column-name-of-a-data-frame -tp4351764p4351764.html Sent from the R help mailing list archive at Nabble.com.
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Sorry, it was not clear: my program have to return column name corresponding to a value, for example 'b' (so, the corresponding column is c1) How to retrieve c1 ? Thanks -- View this message in context: http://r.789695.n4.nabble.com/How-to-retrieve-a-column-name-of-a-data-frame-tp4351764p4351866.html Sent from the R help mailing list archive at Nabble.com.
I'd use something like which(df == "b", arr.ind = TRUE) which, gives the column number in the second spot; this gives you colnames(df)[which(df == "b", arr.ind = TRUE)[2]] Michael
Sorry, it was not clear: my program have to return column name ?corresponding to a value, for example 'b' (so, the corresponding column is c1) How to retrieve c1 ? Thanks -- View this message in context: http://r.789695.n4.nabble.com/How-to-retrieve-a-column-name-of-a-data-frame-tp4351764p4351866.html Sent from the R help mailing list archive at Nabble.com.
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.