Re: dynamic nested loops

*To*: mathgroup at smc.vnet.net*Subject*: [mg122846] Re: dynamic nested loops*From*: DrMajorBob <btreat1 at austin.rr.com>*Date*: Sat, 12 Nov 2011 07:34:23 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201111110956.EAA08550@smc.vnet.net>*Reply-to*: drmajorbob at yahoo.com

Sum has non-standard evaluation-order going on, hence something like this: limits = {{i, 1, 3}, {j, 2, 5}} sum[f[i, j], Sequence @@ limits] /. sum -> Sum {{i, 1, 3}, {j, 2, 5}} f[1, 2] + f[1, 3] + f[1, 4] + f[1, 5] + f[2, 2] + f[2, 3] + f[2, 4] + f[2, 5] + f[3, 2] + f[3, 3] + f[3, 4] + f[3, 5] Bobby On Fri, 11 Nov 2011 03:56:10 -0600, Ron <ragove at verizon.net> wrote: > i need to perform nested sums such as Sum[f, {i,imin,imax},{j, jmin, > jmax}, ...{}]. In each nest the new index is a function of the previous > and the max values vary. Also at the beginning I do not know how long a > nest I need. I can't come up with anything that works. I could > construct a list {{i,imin,imax},{j, jmin, jmax}, ...{}} but "Sum" doen't > know what to do with the outside braces{...}. > ANy suggestions would be much appreciated. > -- DrMajorBob at yahoo.com

**References**:**dynamic nested loops***From:*Ron <ragove@verizon.net>