Re: Summing all the elements along a dimension in a matrix
- To: mathgroup at smc.vnet.net
- Subject: [mg104309] Re: Summing all the elements along a dimension in a matrix
- From: "Nasser M. Abbasi" <nma at 12000.org>
- Date: Tue, 27 Oct 2009 04:58:32 -0500 (EST)
- References: <hc38cr$i5b$1@smc.vnet.net>
"CuppoJava" <patrickli_2001 at hotmail.com> wrote in message news:hc38cr$i5b$1 at smc.vnet.net... > Hi, > I just started using Mathematica after a year of experience with > another system, and I have a question regarding how to handle matrices. > > What is the equivalent code for doing > sum(A,3) in mathematica? > This sums all the elements A along the third dimension. > > I'm having a hard time finding it in the documentation. > > Thanks a lot for your help > -Patrick > another system: --------- >> A A(:,:,1) = 1 2 3 4 A(:,:,2) = 5 6 7 8 >> size(A) 2 2 2 >> sum(A,3) 6 8 10 12 Mathematica --------------------- Dimensions[A = {{{1, 2}, {3, 4}},{{5, 6}, {7, 8}}}] {2, 2, 2} Total[A, 1] {{6, 8}, {10, 12}} --Nasser