dcast特定列并保留所有

我们可以用dcast.该...上的LHS ~包括未在RHS,并在指定的所有变量value.var.

library(reshape2)
dcast(df, ...~element, value.var='value')
#        date year month day gridNumber    PPT    TMAX    TMIN
#1 1899-12-15 1899    12  15     526228 0.0000 43.4782 21.7403
#2 1899-12-16 1899    12  16     526228 0.0000 43.3297 20.7510
#3 1899-12-17 1899    12  17     526229 0.0000 57.3625 25.8157
#4 1899-12-18 1899    12  18     526229 0.2105      NA      NA