Hi I have a data frame like this:
嗨,我有一个这样的数据框:
location = c("100 ail","16th and Whitmore","40AB01 - ANTWERPEN")
lastUpdated = c("2018-02-01 09:30:00", "2018-02-01 03:00:00", "2017-03-07 10:00:00")
firstUpdated = c("2015-09-01 00:00:00","2016-03-06 19:00:00","2016-11-22 15:00:00")
pm25=c("FALSE","FALSE","FALSE")
pm10=c("TRUE","FALSE","FALSE")
no2=c("TRUE","FALSE","FALSE")
latitude=c(47.932907,41.322470,36.809700)
longitude=c(106.92139000,-95.93799000
,-107.65170000)
df = data.frame(location, lastUpdated, firstUpdated,latitude,longitude,pm25,pm10,no2)
I want to extract the colnames of the first row that have value="TRUE". I tried:
我想提取第一行的值为“TRUE”的colnames。我试过了:
colnames(df[1,6:8]=="TRUE")
but without success.
但没有成功。
1 个解决方案
#1
2
You have to use the function which to extract the columns that are equal to TRUE
您必须使用提取等于TRUE的列的函数
colnames(df[,6:8][,which(df[1,6:8]=="TRUE")])
#1
2
You have to use the function which to extract the columns that are equal to TRUE
您必须使用提取等于TRUE的列的函数
colnames(df[,6:8][,which(df[1,6:8]=="TRUE")])