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Re: How to use only part of mapping

• To: mathgroup at smc.vnet.net
• Subject: [mg57267] Re: [mg57257] How to use only part of mapping
• From: DrBob <drbob at bigfoot.com>
• Date: Mon, 23 May 2005 02:20:36 -0400 (EDT)
• References: <200505220414.AAA17638@smc.vnet.net>
• Reply-to: drbob at bigfoot.com
• Sender: owner-wri-mathgroup at wolfram.com

For instance:

Catch@Scan[If[#>5,Throw["Done"],Print@#]&,Range@10]

1
2
3
4
5
Done

Scan could be replaced by Map, or another looping structure.

This is more natural, however, despite the indexing:

i = 1
While[i < 5, Print@i; i++];
"Done"

1
2
3
4
5
Done

Bobby

On Sun, 22 May 2005 00:14:25 -0400 (EDT), Guy Israeli <guyi1 at netvision.net.il> wrote:

> Hi,
>
> I want to do some mapping (/@) related operations since I don't want to use
> for/while loops because of all the index mayhem.
>
> The problem is that I don't need the map operation to continue once some
> condition is met.
>
> Is there a way to stop the mapping operation so it will not continue, thus
> saving valuable calculation time (since there is no need to continue).
>
> for example (not useful though)
>
> Print[#]&/@Range[10]
> and stop printing if #>5
>
>
> If it isn't possible to do it with map, what are my other options?
>
> Thanks,
>
> Guy
>
>
>
>
>



-- 
DrBob at bigfoot.com

• References:
  • How to use only part of mapping
    • From: Guy Israeli <guyi1@netvision.net.il>