相关疑难解决方法(0)

我想对字段进行累积求和,但只要遇到0就重置聚合值.

这是我想要的一个例子:

data.frame(campaign = letters[1:4] , 
       date=c("jan","feb","march","april"),
       b = c(1,0,1,1) ,
       whatiwant = c(1,0,1,2)
       )

 campaign  date b whatiwant
1        a   jan 1         1
2        b   feb 0         0
3        c march 1         1
4        d april 1         2