Re: Summing elements within a List or Array

*To*: mathgroup at smc.vnet.net*Subject*: [mg69548] Re: [mg69524] Summing elements within a List or Array*From*: Sseziwa Mukasa <mukasa at jeol.com>*Date*: Fri, 15 Sep 2006 06:45:25 -0400 (EDT)*References*: <200609141057.GAA21653@smc.vnet.net>

On Sep 14, 2006, at 6:57 AM, John Adeosun wrote: > Hello Everyone, > > I generated an intended list of real numbers using Mathematica 5.2, > say > "alist", that looks like: > > alist = {{0}, {{1.2},0}, {{2.3},{1.2},0},{{3.4},{2.3},{1.2},0}, > ................{{99.0},{98.9},{97.8},.......,0}} > (In Matrix form, this "alist" can be shown as a LowerDiagonal Matrix) > > Meanwhile, my present goal is to then program using Mathematica to > obtain a > list, say "aalist", having each element equal to the sum of the > elements in > each(corresponding) sublist of the original list "alist." That is, > > aalist = {0, 1.2, 3.5, 6.9,...........} > > In essence, it is like reducing, say, 100 by 100 matrix to 100 by 1 > matrix > via summing operation. > > I programmed using some summing operations/functions in > Mathematica to no > avail. I don't know what I 'm doing wrong. > > Can anyone help with this problem? aalist=Plus@@Flatten[#]&/@alist Regards, Ssezi

**References**:**Summing elements within a List or Array***From:*"John Adeosun" <jtadeosun@yahoo.com>