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If I have a vector of a cumulative sum, e.g.
> vec <- cumsum(1:10) [1] 1 3 6 10 15 21 28 36 45 55 is there a functional way to translate vec into it's original vector of c(1:10)?
Right now, I'm using a for-loop that goes:
> result <- vec[1] > for (i in 2:length(vec)) result <- append(result, vec[i]-vec[i-1]) > result [1] 1 2 3 4 5 6 7 8 9 10 But that doesn't seem very R like to me... Any ideas?
615
Returns a vector of cumulative sums of the input values, running in reverse order.
Reverse cumulative sum of a column is calculated using rev() and cumsum() function. cumsum() function takes up column name as argument which computes the cumulative sum of the column and it is passed to rev() function which reverses the cumulative sum as shown below.
A running total, or cumulative sum, is a sequence of partial sums of a given data set. It is used to show the summation of data as it grows with time (updated every time a new number is added to the sequence).
Cumulative sums, or running totals, are used to display the total sum of data as it grows with time (or any other series or progression). This lets you view the total contribution so far of a given measure against time.
Just use diff to get the successive differences:
> c(vec[1],diff(vec)) [1] 1 2 3 4 5 6 7 8 9 10 If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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