adding elements in vectors (not matrices) in a list in R

Question

Consider I have the following list in which each element of the list is a vector and not a matrix (with s number of cols and rows) -

$a
[1] 1 2 3 4 5 

$b
[1] 1 2 3 4 5

$c
[1] 1 2 3 4 5

I want to add across the elements (1,2 3..) of each vector (a, b, c) such that-

$Total
[1] 3 6 9 12 15

How do I do this in R?

`Reduce(`+`, your_list)` or `colSums(do.call(rbind, your_list))` — Sotos, Mar 16 '17 at 15:38
Possible duplicate of [Is there an R function for the element-wise summation of the matrices stored as elements in single list object?](http://stackoverflow.com/questions/14147655/is-there-an-r-function-for-the-element-wise-summation-of-the-matrices-stored-as) — Ronak Shah, Mar 16 '17 at 15:44
since you have equal number of elements in each list element, you can also use `rowSums(as.data.frame(x))` — talat, Mar 16 '17 at 15:58

Zheyuan Li · Accepted Answer · 2017-03-16T15:42:33.297

1

Here is one way:

rowSums(simplify2array(lst))

where lst is your list.

edited Mar 16 '17 at 15:42

answered Mar 16 '17 at 15:38

Zheyuan Li

1

It is simplify. – lmo Mar 16 '17 at 15:40
are you on phone? – akrun Mar 16 '17 at 17:33
Ohh, that is terrible. – akrun Mar 16 '17 at 17:36
@李哲源ZheyuanLi Yes, I thought you got busy with some research work – akrun Mar 16 '17 at 17:40
@李哲源ZheyuanLi Good luck with the viva! – akrun Mar 16 '17 at 17:42

1 Answers1