[R] Remove

Ista Zahn istazahn at gmail.com
Thu Dec 7 00:59:55 CET 2017


Hi Ashta,

There are many ways to do it. Here is one:

vars <- sapply(split(DM$x, DM$GR), var)
DM[DM$GR %in% names(vars[vars > 0]), ]

Best
Ista

On Wed, Dec 6, 2017 at 6:58 PM, Ashta <sewashm at gmail.com> wrote:
> Thank you Jeff,
>
> subset( DM, "B" != x ), this works if I know the group only.
> But if I don't know that group in this case "B", how do I identify
> group(s) that  all elements of x have the same value?
>
> On Wed, Dec 6, 2017 at 5:48 PM, Jeff Newmiller <jdnewmil at dcn.davis.ca.us> wrote:
>> subset( DM, "B" != x )
>>
>> This is covered in the Introduction to R document that comes with R.
>> --
>> Sent from my phone. Please excuse my brevity.
>>
>> On December 6, 2017 3:21:12 PM PST, David Winsemius <dwinsemius at comcast.net> wrote:
>>>
>>>> On Dec 6, 2017, at 3:15 PM, Ashta <sewashm at gmail.com> wrote:
>>>>
>>>> Hi all,
>>>> In a data set I have group(GR) and two variables   x and y. I want to
>>>> remove a  group that have  the same record for the x variable in each
>>>> row.
>>>>
>>>> DM <- read.table( text='GR x y
>>>> A 25 125
>>>> A 23 135
>>>> A 14 145
>>>> A 12 230
>>>> B 25 321
>>>> B 25 512
>>>> B 25 123
>>>> B 25 451
>>>> C 11 521
>>>> C 14 235
>>>> C 15 258
>>>> C 10 654',header = TRUE, stringsAsFactors = FALSE)
>>>>
>>>> In this example the output should contain group A and C  as group B
>>>> has   the same record  for the variable x .
>>>>
>>>> The result will be
>>>> A 25 125
>>>> A 23 135
>>>> A 14 145
>>>> A 12 230
>>>> C 11 521
>>>> C 14 235
>>>> C 15 258
>>>> C 10 654
>>>
>>>Try:
>>>
>>>DM[ !duplicated(DM$x) , ]
>>>>
>>>> How do I do it R?
>>>> Thank you.
>>>>
>>>> ______________________________________________
>>>> R-help at 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.
>>>
>>>David Winsemius
>>>Alameda, CA, USA
>>>
>>>'Any technology distinguishable from magic is insufficiently advanced.'
>>>  -Gehm's Corollary to Clarke's Third Law
>>>
>>>______________________________________________
>>>R-help at 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.
>
> ______________________________________________
> R-help at 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.



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