按日期减去 R 数据框中的行

Question

I have a dataframe, df , like this one:

           Date Colombia    Chile
2015-01-01  2015 38.12333 31.92088
2020-01-01  2020 44.95952 38.10776

And I would like to substract the 2015 values, for each country, from the values in 2020, so I could get a new dataframe looking loke this one:

           Date Colombia    Chile
2020-01-01  2020 6.83619    6.18688

But I would like to do it by dates, ie, the identifier is that the value of the lower date is subtracted from the value of the higher date in each country.

Can you guys help me out?

Answer 1

diff(as.matrix(df))
           Date Colombia   Chile
2020-01-01    5  6.83619 6.18688