CODEWITHSUNDEEP
rdate
user2363642
user2363642

Reputation: 757

convert specified columns to dates in R

I want to convert numeric data in columns 2:4 to dates. I can do this column by column but can't do it all it all in one go. I figure it has something to do with the names column being in there, but I try to tell R just to use the columns I want. What am I doing wrong? Thanks in advance!

names<-c("tom", "dick", "harry", "mary", "susie")
date_1<-c(15127, 15034, 15034, 15141, 15013)
date_2<-c(15155, 15062, 15064, NA, 15041)
date_3<-c(15185, 15091, 15092, NA, 15069)
df<-data.frame(names, date_1, date_2, date_3)
df




as.Date(df$date_1, origin="1970-01-01")
[1] "2011-06-02" "2011-03-01" "2011-03-01" "2011-06-16" "2011-02-08"


as.Date(df[,2:4], origin="1970-01-01")
Error in as.Date.default(df[, 2:4], origin = "1970-01-01") : 
  do not know how to convert 'df[, 2:4]' to class “Date”

Upvotes: 0

Views: 2421

Answers (1)

joran
joran

Reputation: 173517

Data frames are lists. Use lapply:

df[,-1] <- lapply(df[,-1],as.Date,origin = "1970-01-01")
> df
  names     date_1     date_2     date_3
1   tom 2011-06-02 2011-06-30 2011-07-30
2  dick 2011-03-01 2011-03-29 2011-04-27
3 harry 2011-03-01 2011-03-31 2011-04-28
4  mary 2011-06-16       <NA>       <NA>
5 susie 2011-02-08 2011-03-08 2011-04-05

Upvotes: 2

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