summation optimization
- To: mathgroup at smc.vnet.net
- Subject: [mg15326] summation optimization
- From: "Arturas Acus" <acus at itpa.lt>
- Date: Fri, 8 Jan 1999 04:15:16 -0500
- Sender: owner-wri-mathgroup at wolfram.com
Hello, Suppose I wish to do multiple sums explicitly. Which one method is preferable and how much time it can save? What about memory usage? Method 1: Sum[a[i,j],{i,?,?},{j,?,?}]+ Sum[b[i,k,m],{i,?,?},{k,!,!},{m,*,*}] Method 2: Sum[Sum[a[i,j],{j,?,?}]+Sum[b[i,k,m],{k,!,!},{m,*,*}],{i,?,?}] Generally, how much grouping of similar indices can be effective? Arturas Acus Institute of Theoretical Physics and Astronomy Gostauto 12, 2600,Vilnius Lithuania E-mail: acus at itpa.lt Fax: 370-2-225361 Tel: 370-2-612906