How to calculate cumulative sum? [duplicate]

问题:

This question already has an answer here:

• Calculating cumulative sum for each row 4 answers
• Vector of cumulative sums in R 1 answer

I have data containing columns biweek and Total, I want to get cumulative sum on biweek basis. My data is like:

biweek  Total
0   3060.913
1   4394.163
2   3413.748
3   2917.548
4   3442.055
5   3348.398
6   1771.722

and I want to get output like :

biweek  Total
0   3060.913
1   7455.076
2   10868.824
3   13786.372
4   17228.427
5   20576.825
6   22348.547

So it there a possible way to achieve it?

回答1:

# replace the second column for the cumsum of the initial second column
data[, 2] <- cumsum(data[, 2])