Re: Mapping tag-value lists to a third
- To: mathgroup at smc.vnet.net
- Subject: [mg132446] Re: Mapping tag-value lists to a third
- From: Bob Hanlon <hanlonr357 at gmail.com>
- Date: Tue, 18 Mar 2014 01:28:24 -0400 (EDT)
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- References: <20140317062731.30FA06A09@smc.vnet.net>
tag = {0, 1, 0, 0, 0, 1, 0, 1};
val = {f1, f2, f3, f4, f5, f6, f7, f8};
Pick[val, tag, 1]
{f2, f6, f8}
Bob Hanlon
On Mon, Mar 17, 2014 at 2:27 AM, <
carlos.felippa%colorado.edu at gtempaccount.com> wrote:
> Hi,
>
> I have 2 lists of equal length such as
>
> tag={0, 1, 0, 0, 0, 1, 0, 1}; val={f1,f2,f3,f4,f5,f6,f7,f8}
>
> and want to produce a third:
>
> tagval={f2,f6,f8}
>
> with length Count[tag,1] containing the entries of val marked by 1-tags.
> Should be
> something efficient, since the source lists may be large (10^6 to 10^7).
> Thanks.
>
- References:
- Mapping tag-value lists to a third
- From: carlos.felippa%colorado.edu@gtempaccount.com
- Mapping tag-value lists to a third