[R] match() question or needle haystack problem for a data.frame

[Bert Gunter]

Re-read ?match and note the examples for %in%

-- Bert
Bert Gunter

"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Mon, Oct 22, 2018 at 7:38 AM Knut Krueger <rhelp using krueger-family.de>
wrote:

>
> Hi to all
>
> I would like to reduce the "Mydata" to rows, only if Mydata$Data1 are in
> needles
>
>
>
> needles =c(14390, 14391, 14392, 14427, 14428, 14429, 14430, 14431,
> 14432, 14433, 14434, 14435, 14436, 14437, 14439, 14440, 14441, 15195,
> 15196, 15197, 15198, 15199, 15200, 15201, 15202, 15203, 15204, 15205,
> 15206, 15207, 15208, 15209, 17615, 17616, 17617, 17618, 17619, 17620,
> 17621, 17622, 17623, 17624, 17625, 17626, 17627, 17628, 17629, 17630,
> 17631, 17679, 17680, 17681, 17682, 17683, 17823, 17824, 17825, 17826,
> 17827, 17828, 17829, 17830, 17831, 17862, 17863, 17864, 17865, 17866,
> 17867, 17868, 17869, 17870, 17871, 17872, 17873, 17874, 17875, 17876,
> 17877, 17878, 17879, 17880, 17881, 17882, 17883, 19255, 19256, 19257,
> 19258, 21289, 21290, 21291, 21292, 22890, 22891, 22892, 22893, 22894,
> 22895, 22896, 22897, 22898, 22899, 22900, 22901, 22902, 40428, 40429,
> 40430, 40431, 40432, 40433, 40434, 40435, 40436, 40437)
>
> Haystack =c(14390, 14391, 14392, 14427, 14428, 14429, 14430, 14431,
> 14432, 14433, 14434, 14435, 14436, 14437, 14439, 14440, 14441, 15187,
> 15188, 15195, 15196, 15197, 15198, 15199, 15200, 15201, 15202, 15203,
> 15204, 15205, 15206, 15207, 15208, 15209, 16717, 16718, 17615, 17616,
> 17617, 17618, 17619, 17620, 17621, 17622, 17623, 17624, 17625, 17626,
> 17627, 17628, 17629, 17630, 17631, 17679, 17680, 17681, 17682, 17683,
> 17817, 17818, 17823, 17824, 17825, 17826, 17827, 17828, 17829, 17830,
> 17831, 17862, 17863, 17864, 17865, 17866, 17867, 17868, 17869, 17870,
> 17871, 17872, 17873, 17874, 17875, 17876, 17877, 17878, 17879, 17880,
> 17881, 17882, 17883, 17886, 19255, 19256, 19257, 19258, 21289, 21290,
> 21291, 21292, 22890, 22891, 22892, 22893, 22894, 22895, 22896, 22897,
> 22898, 22899, 22900, 22901, 22902, 40428, 40429, 40430, 40431, 40432,
> 40433, 40434, 40435, 40436, 40437, 40710, 40711, 49127, 49128, 52768)
>
> Mydata =data.frame (DATA1=Haystack, Data2=c(1:length(Haystack)))
>
>
>
> match(Mydata$DATA1, needles, nomatch=NA) does find all data which are in
> needle - the others are set to the nomatch value.
>
> But I don not find out how to reduce the data.frame  -  maybe match() is
> not helpful for that.
>
> Kind regards Knut
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

	[[alternative HTML version deleted]]