From a data frame, is there a easy way to aggregate (
max et c) multiple variables simultaneously?
Below are some sample data:
library(lubridate) days = 365*2 date = seq(as.Date("2000-01-01"), length = days, by = "day") year = year(date) month = month(date) x1 = cumsum(rnorm(days, 0.05)) x2 = cumsum(rnorm(days, 0.05)) df1 = data.frame(date, year, month, x1, x2)
I would like to simultaneously aggregate the
x2 variables from the
df2 data frame by year and month. The following code aggregates the
x1 variable, but is it also possible to simultaneously aggregate the
### aggregate variables by year month df2=aggregate(x1 ~ year+month, data=df1, sum, na.rm=TRUE) head(df2)
Any suggestions would be greatly appreciated.