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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