Re: Summation in Mathematica

*To*: mathgroup at smc.vnet.net*Subject*: [mg130608] Re: Summation in Mathematica*From*: debguy <johnandsara2 at cox.net>*Date*: Thu, 25 Apr 2013 02:56:04 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net*References*: <kl8e4n$on7$1@smc.vnet.net>

UnderoverscriptBox[\(\[Sum]\), \(m = \(-10\)\), \(10\)]\(\(eigenfunctionsort[n, j]\)[\([m + 11]\)] Exp[I*2*\[Pi]*m*x/dp]\)\),{j,1,21}] // DisplayForm does not work on my mm v. 4.0 and I'm unsure what's missing. a table or another Sum involving j maybe? I'm getting a \(\) not paired error and missing [. but as I see it fun[[m+11]] necessarily means to take a Part of eigenfunctionsort[n, j] ; which isn't obviously a number, list, or symbol from where I sit. Ben Blomberg wrote: > Hello All, > > I am trying to understand a piece of code I found but I am stuck on this > summation. This is part of a larger do loop over n. > > UnderoverscriptBox[\(\[Sum]\), \(m = \(-10\)\), > \(10\)]\(\(eigenfunctionsort[n, j]\)[\([m + 11]\)] > Exp[I*2*\[Pi]*m*x/dp]\)\),{j,1,21}] > > What I mainly do not understand is what is happening with the [m+11]. Is > that being multiplied with eigen function sort with each step in the sum, > or is that simply adding 11 to m at each step in the sum? > > Thanks Ben