R: How to retrieve a column name of a data frame
Clash Royale CLAN TAG #URR8PPP R: How to retrieve a column name of a data frame I am trying to extract the colnames of a data frame, based on the values in the cells. My data is a series of a couple hundred categories, with a simple binary 0 or 1 in the cells to indicate which column name I want in my new df. To illustrate my point: year cat1 cat2 cat3 ... catN 2000 0 0 1 0 2001 1 0 0 0 2002 0 0 0 1 .... 2018 0 1 0 0 I am trying to get a df like: year category 2000 cat3 2001 cat1 2002 catN .... 2018 cat2 My code: newdf <- as.data.frame(colnames(mydf)[which(mydf == "1", arr.ind = TRUE)[2]]) But alas this only returns one category name! Any help would be greatly appreciated! 1 Answer 1 A possible solution is this: library(tidyverse) df = data.frame(year = 2000:2002, cat1 = c(0,0,1), cat2 = c(1...