cumsum(x)
cumsum returns a vector the same length of x, but whose elements are the cumulative sums of those in x. An NA value in x will cause sums involving that element to have value NA.
x, but whose elements are the cumulative sums of those in x. An NA value in x will cause sums involving that element to have value NA.
x. An NA value in x will cause sums involving that element to have value NA.
NA value in x will cause sums involving that element to have value NA.
x will cause sums involving that element to have value NA.
NA.