Re: Adding the elements of a list sequentially

*To*: mathgroup at smc.vnet.net*Subject*: [mg109357] Re: Adding the elements of a list sequentially*From*: Ray Koopman <koopman at sfu.ca>*Date*: Fri, 23 Apr 2010 03:48:40 -0400 (EDT)*References*: <hqotti$9ch$1@smc.vnet.net>

On Apr 22, 12:29 am, eba... at illinois.edu wrote: > I am looking for an efficient way to add the elements of a list > sequentially onto another list > > For example, generate list c, given lists a and b: > > a = {1,2,3,4,5,6,7,8,9,10} > b = {1,2} > > c = {2,4,4,5,6,7,8,9,10,11} > > another example: > > a = {1,1,1,1,1} > b = {1,2,3} > > c = {2,3,4,2,3} > > It seems like there must be a built in function to do this, > but have been unable to find it. > > Thanks a 10^6 > Jason Ebaugh a = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; b = {1, 2}; Total@PadRight@{a, b} {2, 4, 3, 4, 5, 6, 7, 8, 9, 10} Total@PadRight@{b, a} {2, 4, 3, 4, 5, 6, 7, 8, 9, 10}