[R] dplyr - counting a number of specific values in each column - for all columns at once
David Winsemius
dwinsemius at comcast.net
Tue Jun 16 22:42:41 CEST 2015
On Jun 16, 2015, at 11:18 AM, Clint Bowman wrote:
> Thanks, Dimitri. Burt is the real wizard here--I'll bet he can conjure up an elegant solution.
This would be base method:
> by( md[-4]==5, md[4], colSums)
device: 1
a b c
1 2 0
-----------------------------------------------------
device: 2
a b c
1 1 0
-----------------------------------------------------
device: 3
a b c
1 0 2
You could adapt that to use myvars:
> by(md[myvars]==5, md[!names(md) %in% myvars],colSums)
device: 1
a b c
1 2 0
-----------------------------------------------------
device: 2
a b c
1 1 0
-----------------------------------------------------
device: 3
a b c
1 0 2
And if you want them smushed into a matrix then use rbind:
> do.call( rbind, by(md[myvars]==5, md[!names(md) %in% myvars],colSums))
a b c
1 1 2 0
2 1 1 0
3 1 0 2
>
> For me, just reaching a desired endpoint is enough<g>.
>
> Clint
>
> Clint Bowman INTERNET: clint at ecy.wa.gov
> Air Quality Modeler INTERNET: clint at math.utah.edu
> Department of Ecology VOICE: (360) 407-6815
> PO Box 47600 FAX: (360) 407-7534
> Olympia, WA 98504-7600
>
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>
> On Tue, 16 Jun 2015, Dimitri Liakhovitski wrote:
>
>> Thank you, Clint.
>> That's the thing: it's relatively easy to do it in base, but the
>> resulting code is not THAT simple.
>> I thought dplyr would make it easy...
>>
>> On Tue, Jun 16, 2015 at 2:06 PM, Clint Bowman <clint at ecy.wa.gov> wrote:
>>> May want to add headers but the following provides the device number with
>>> each set fo sums:
>>>
>>> for (dev in (unique(md$device)))
>>> {cat(colSums(subset(md,md$device==dev)==5,na.rm=T),dev,"\n")}
>>>
>>> Clint Bowman INTERNET: clint at ecy.wa.gov
>>> Air Quality Modeler INTERNET: clint at math.utah.edu
>>> Department of Ecology VOICE: (360) 407-6815
>>> PO Box 47600 FAX: (360) 407-7534
>>> Olympia, WA 98504-7600
>>>
>>> USPS: PO Box 47600, Olympia, WA 98504-7600
>>> Parcels: 300 Desmond Drive, Lacey, WA 98503-1274
>>>
>>> On Tue, 16 Jun 2015, Dimitri Liakhovitski wrote:
>>>
>>>> Except, of course, Bert, that you forgot that it had to be done by
>>>> device. Your solution ignores the device.
>>>>
>>>> md <- data.frame(a = c(3,5,4,5,3,5), b = c(5,5,5,4,4,1), c =
>>>> c(1,3,4,3,5,5),
>>>> device = c(1,1,2,2,3,3))
>>>> myvars = c("a", "b", "c")
>>>> md[2,3] <- NA
>>>> md[4,1] <- NA
>>>> md
>>>> vapply(md[myvars], function(x) sum(x==5,na.rm=TRUE),1L)
>>>>
>>>> But the result should be by device.
>>>>
>>>> On Tue, Jun 16, 2015 at 1:56 PM, Dimitri Liakhovitski
>>>> <dimitri.liakhovitski at gmail.com> wrote:
>>>>>
>>>>> Thank you, Bert.
>>>>> I'll be honest - I am just learning dplyr and was wondering if one
>>>>> could do it in dplyr.
>>>>> But of course your solution is perfect...
>>>>>
>>>>> On Tue, Jun 16, 2015 at 1:50 PM, Bert Gunter <bgunter.4567 at gmail.com>
>>>>> wrote:
>>>>>>
>>>>>> Well, dplyr seems a bit of overkill as it's so simple with plain old
>>>>>> vapply() in base R :
>>>>>>
>>>>>>
>>>>>>> dat <- data.frame (a=sample(1:5,10,rep=TRUE),
>>>>>>
>>>>>> + b=sample(3:7,10,rep=TRUE),
>>>>>> + g = sample(7:9,10,rep=TRUE))
>>>>>>
>>>>>>> vapply(dat,function(x)sum(x==5,na.rm=TRUE),1L)
>>>>>>
>>>>>>
>>>>>> a b g
>>>>>> 5 4 0
>>>>>>
>>>>>>
>>>>>>
>>>>>> Cheers,
>>>>>> Bert
>>>>>>
>>>>>> Bert Gunter
>>>>>>
>>>>>> "Data is not information. Information is not knowledge. And knowledge is
>>>>>> certainly not wisdom."
>>>>>> -- Clifford Stoll
>>>>>>
>>>>>> On Tue, Jun 16, 2015 at 10:24 AM, Dimitri Liakhovitski
>>>>>> <dimitri.liakhovitski at gmail.com> wrote:
>>>>>>>
>>>>>>>
>>>>>>> Hello!
>>>>>>>
>>>>>>> I have a data frame:
>>>>>>>
>>>>>>> md <- data.frame(a = c(3,5,4,5,3,5), b = c(5,5,5,4,4,1), c =
>>>>>>> c(1,3,4,3,5,5),
>>>>>>> device = c(1,1,2,2,3,3))
>>>>>>> myvars = c("a", "b", "c")
>>>>>>> md[2,3] <- NA
>>>>>>> md[4,1] <- NA
>>>>>>> md
>>>>>>>
>>>>>>> I want to count number of 5s in each column - by device. I can do it
>>>>>>> like
>>>>>>> this:
>>>>>>>
>>>>>>> library(dplyr)
>>>>>>> group_by(md, device) %>%
>>>>>>> summarise(counts.a = sum(a==5, na.rm = T),
>>>>>>> counts.b = sum(b==5, na.rm = T),
>>>>>>> counts.c = sum(c==5, na.rm = T))
>>>>>>>
>>>>>>> However, in real life I'll have tons of variables (the length of
>>>>>>> 'myvars' can be very large) - so that I can't specify those counts.a,
>>>>>>> counts.b, etc. manually - dozens of times.
>>>>>>>
>>>>>>> Does dplyr allow to run the count of 5s on all 'myvars' columns at
>>>>>>> once?
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Dimitri Liakhovitski
>>>>>>>
>>>>>>> ______________________________________________
>>>>>>> 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.
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Dimitri Liakhovitski
>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Dimitri Liakhovitski
>>>>
>>>> ______________________________________________
>>>> 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.
>>>>
>>>
>>
>>
>>
>> --
>> Dimitri Liakhovitski
>>
>
> ______________________________________________
> 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
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