Re: speeding up intergration of sum

*To*: mathgroup at smc.vnet.net*Subject*: [mg126487] Re: speeding up intergration of sum*From*: A Retey <awnl at gmx-topmail.de>*Date*: Mon, 14 May 2012 01:35:29 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <jonme3$gfe$1@smc.vnet.net>

Am 13.05.2012 09:04, schrieb Bill Rowe: > On 5/12/12 at 4:51 AM, bar at ANTYSPAM.ap.krakow.pl wrote: > >> Hello, I have a problem with Integrate[f[z]] where f[z] is a sum of >> many parts, > >> All those parts are very simple ( like a/(b+z) ) > >> Sometimes Integrate[f[z],z] doesn't reach convergence > >> althouhg Integrate of the all of parts exists, > >> The question is : Is it possible to force the Mathematica to >> calculate this sum > >> step by step (part by part) ?? > > Yes, if f[z] is just a sum of terms then you could do either > > Total@Integrate[List@@f[z],z] > > or > > Total[Integrate[#,z]&/@List@@f[z]] > > Either will cause Mathematica to integrate each term > individually then sum the results of each integration. I don't > know whether this will be faster or not for your situation. I think there is no need to turn the Plus to a List and back, Map will work happily with the original head Plus: Integrate[#, z] & /@ f[z] hth, albert