| Original Message (ID '161425') By Vojta: |
| In Response To 'Re: Slowdown of computation of multiple sums'
---------
Let me rephrase my question. Lets say I want to make sum
Sum[function[n],{n,min,max}]
where function[n] is defined as
function[n_]:=Sum[differentfunction[n,i,j,k],{i,imin,imax},{j,jmin,jmax},{k,kmin,kmax}]
where differentfunction[n,i,j,k] can be quite complicated function which could even contain i-th derivatives of some genereting function etc.
Now, when the sum over n is calculated, will it have to run internally in every term for every n all the summations over i,j,k which are in the definition of function[n]? Or will those sums be done at the beginning and then Mathematica will just insert values of n from nmin to nmax? |
|
