Re: Re: problem with Pick
- To: mathgroup at smc.vnet.net
- Subject: [mg78494] Re: [mg78409] Re: problem with Pick
- From: DrMajorBob <drmajorbob at bigfoot.com>
- Date: Tue, 3 Jul 2007 05:25:34 -0400 (EDT)
- References: <acbec1a40706230431p4f1db9a9i4320680dda027396@mail.gmail.com> <200707010731.DAA01680@smc.vnet.net> <86E8AE9E-5C16-4DE7-A78D-F7766C0D8E02@mimuw.edu.pl> <21764490.1183381902174.JavaMail.root@m35> <op.tuus22zfqu6oor@monster.ma.dl.cox.net> <23903468.1183413753892.JavaMail.root@m35>
- Reply-to: drmajorbob at bigfoot.com
If I were collecting indices on some criterion and didn't get any, I'd want the result to be some logical equivalent of NOTHING, not EVERYTHING. expr[[]] = Head[expr][], for instance. But Mathematica doesn't do it that way so, as I've said before, we'll just have to adjust our expectations. Bobby On Mon, 02 Jul 2007 16:58:11 -0500, Chris Chiasson <chris at chiasson.name> wrote: > On 7/2/07, DrMajorBob <drmajorbob at bigfoot.com> wrote: > <snip/> >> Nor have I seen an example in which [[]] is useful, rather than >> needlessly >> puzzling. >> >> (Unless I blinked and missed it.) > > It could be useful if one is generating the arguments to Part via a > program. If there are no sub-parts needed, then Sequence[] should be > sent as the second argument. > -- DrMajorBob at bigfoot.com
- References:
- Re: problem with Pick
- From: Chris Chiasson <chris.chiasson@gmail.com>
- Re: problem with Pick