Re: Pure Function within a pure function
- To: mathgroup at smc.vnet.net
- Subject: [mg59326] Re: Pure Function within a pure function
- From: Wonseok Shin <wssbus at gmail.com>
- Date: Fri, 5 Aug 2005 01:23:11 -0400 (EDT)
- References: <dcsbi3$pub$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
On 2005-08-03 23:11:15 -0700, ggroup at sarj.ca said:
> Hi,
>
> I'm wondering if it is possible to define a pure function within a
> function, and if so, what syntax should I be using?
>
> I have some data that I want to filter, say:
>
> rawdata[[1]]=
> time1 pt1-1 pt1-2 pt1-3
> time2 pt2-1 pt2-2 pt2-3
> time3 aborted!
>
> rawdata[[2]]=
> time1 pta-1 pta-2 pta-3
> time2 aborted!
>
> I have a list of such data sets, and I want to apply a filter to remove
> the "aborted" lines to each set. With a table command, this is fairly
> easy:
>
> data = Table[
> Select[rawdata[[i]],Length[#]==4&],
> {i,Length[rawdata]}
> ]
>
> For readability (and lets face it, for pure asthetic value), I was
> hoping to convert this to a function which I could map onto my rawdata
> array. I tried something like:
>
> data = Select[#, Length[#]==4&]& /@ rawdata;
>
> But this doesn't work. I imagine the confusion is with the comparison
> function Length[#]==4&, but I'm having no luck figuring out how to make
> it less ambiguous.
>
> Any pointers would be much appreciated.
>
> Thanks!
>
> PS: I'm using version 5.2 on Windows.
How about this?
Select[#, Length[#] == 4 &] & @@ {data}
It seems to work fine. Note that I used @@ instead of /@.
--
Wonseok Shin
wssaca at gmail.com