如何选择最新日期＆amp; R中每行的时间？

Question

Df1

2017-01-27 01

2017-01-26 03

2017-01-27 15

2017-04-03 02

Df2

2017-01-26 03

2017-01-27 00

2017-01-27 15

2017-04-03 18

最新

2017-01-27 01

2017-01-27 00

2017-01-27 15

2017-04-03 18

Answer 1

apply(data.frame(a=c("2016-01-01","2016-02-01", "2017-01-01"),
             b=c("2016-02-01","2016-01-01", "2016-12-01")), 1, max)

这应该为您提供每行的最新日期