I have a data set that resembles this:
> data
Year X1 X2 X3
1 1990 1 0 0
2 1990 0 1 0
3 1991 0 0 0
4 1991 1 0 1
5 1991 1 1 1
6 1992 0 1 0
And I am trying to sum up X1, X2, and X3 by year, such that the end-result is:
> aggr_data
Year X1 X2 X3
1 1990 1 1 0
2 1991 2 1 2
3 1992 0 1 0
I know that I can sum each column by year using dplyr:
aggr_data$X1 <- data %>%
group_by(year) %>%
summarise(sum.amount = sum(X1))
However, it is tedious to do it for every variable in my dataset, and even if I were to do so, the result is two lists of the year and the sum amounts, instead of a dataframe which I need.
Is there a way for me to simultaneously sum the columns by year, such that the end result is a dataframe comprising a year column and the summed amounts?
Thanks for your help!
