[R] Remove

[David Winsemius]

> On Dec 8, 2017, at 4:48 PM, Ashta <sewashm at gmail.com> wrote:
> 
> Hi David, Ista and all,
> 
> I  have one related question  Within one group I want to keep records
> conditionally.
> example within
> group A I want keep rows that have  " x" values  ranged  between 15 and 30.
> group B I want keep rows that have  " x" values  ranged  between  40 and 50.
> group C I want keep rows that have  " x" values  ranged  between  60 and 75.

When you have a problem where there are multiple "parallel: parameters, the function to "reach for" is `mapply`. 

    mapply( your_selection_func, group_vec, min_vec, max_vec)

... and this will probably return the values as a list (of dataframes if you build the function correctly,  so you may may need to then do:

    do.call(rbind, ...)

-- 
David.
> 
> 
> DM <- read.table( text='GR x y
> A 25 125
> A 23 135
> A 14 145
> A 35 230
> B 45 321
> B 47 512
> B 53 123
> B 55 451
> C 61 521
> C 68 235
> C 85 258
> C 80 654',header = TRUE, stringsAsFactors = FALSE)
> 
> 
> The end result will be
> A 25 125
> A 23 135
> B 45 321
> B 47 512
> C 61 521
> C 68 235
> 
> Thank you
> 
> On Wed, Dec 6, 2017 at 10:34 PM, David Winsemius <dwinsemius at comcast.net> wrote:
>> 
>>> On Dec 6, 2017, at 4:27 PM, Ashta <sewashm at gmail.com> wrote:
>>> 
>>> Thank you Ista! Worked fine.
>> 
>> Here's another (possibly more direct in its logic?):
>> 
>> DM[ !ave(DM$x, DM$GR, FUN= function(x) {!length(unique(x))==1}), ]
>>  GR  x   y
>> 5  B 25 321
>> 6  B 25 512
>> 7  B 25 123
>> 8  B 25 451
>> 
>> --
>> David
>> 
>>> On Wed, Dec 6, 2017 at 5:59 PM, Ista Zahn <istazahn at gmail.com> wrote:
>>>> 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.
>>> 
>>> ______________________________________________
>>> 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
>> 
>> 
>> 
>> 
>> 

David Winsemius
Alameda, CA, USA

'Any technology distinguishable from magic is insufficiently advanced.'   -Gehm's Corollary to Clarke's Third Law