Re: Summing elements within a List or Array
- To: mathgroup at smc.vnet.net
- Subject: [mg69543] Re: Summing elements within a List or Array
- From: dh <dh at metrohm.ch>
- Date: Fri, 15 Sep 2006 06:45:06 -0400 (EDT)
- References: <eebfs6$57q$1@smc.vnet.net>
Hi John, this should do it: alist = {{0}, {{1.2}, 0}, {{2.3}, {1.2}, 0}, {{3.4}, {2.3}, {1.2}, 0}}; Plus @@ Flatten[#] & /@ alist Daniel 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? > > Thanks, > > John. > >