[R] subsetting a data frame
stephen sefick
ssefick at gmail.com
Sat Sep 6 20:55:27 CEST 2008
Sorry I didn't read the problem carefully.
On Sat, Sep 6, 2008 at 2:53 PM, Jorge Ivan Velez
<jorgeivanvelez at gmail.com> wrote:
>
> Hi Joseph,
> Try this:
> # Data set
> DF=read.table(textConnection("V1 V2 V3
> a b 0:1:12
> d f 1:2:1
> c d 1:0:9
> b e 2:2:6
> f c 5:5:0"),header=TRUE)
> closeAllConnections()
>
> target=10
> DF[sapply(strsplit(as.character(DF$V3), ":"), function(x)
> sum(as.numeric(x))== target), ]
>
> HTH,
> Jorge
>
>
> On Sat, Sep 6, 2008 at 2:25 PM, joseph <jdsandjd at yahoo.com> wrote:
>>
>> Hi Jorge
>> I got the rows where V3 looks like this 10:10:10; Ithe sum here is 30
>> and not 10.
>> I want the rows where the sum is 10 for exaple 5:5:0 and 2:2:6
>> thanks
>> Joseph
>>
>> ----- Original Message ----
>> From: Jorge Ivan Velez <jorgeivanvelez at gmail.com>
>> To: joseph <jdsandjd at yahoo.com>
>> Sent: Saturday, September 6, 2008 10:43:09 AM
>> Subject: Re: [R] subsetting a data frame
>>
>>
>> Dear Joseph,
>> Try
>>
>> DF[sapply(strsplit(as.character(DF$V3), ":"),
>> function(i) all(as.numeric(i) == 10)), ]
>> HTH,
>> Jorge
>>
>> On Sat, Sep 6, 2008 at 1:24 PM, joseph <jdsandjd at yahoo.com> wrote:
>>>
>>> Hello
>>> How can I change the function to get the rows with the sum (x+y+z) = 10?
>>> Thank you very much
>>> Joseph
>>>
>>>
>>>
>>> ----- Original Message ----
>>> From: Marc Schwartz <marc_schwartz at comcast.net>
>>> To: joseph <jdsandjd at yahoo.com>
>>> Cc: r-help at r-project.org
>>> Sent: Wednesday, September 3, 2008 3:24:58 PM
>>> Subject: Re: [R] subsetting a data frame
>>>
>>> on 09/03/2008 05:06 PM joseph wrote:
>>> > I have a data frame that looks like this:
>>> > V1 V2 V3
>>> > a b 0:1:12
>>> > d f 1:2:1
>>> > c d 1:0:9
>>> > where V3 is in the form x:y:z
>>> > Can someone show me how to subset the rows where the values of x, y and
>>> > z <= 10:
>>> > V1 V2 V3
>>> > d f 1:2:1
>>> > c d 1:0:9
>>> > Thanks
>>> > Joseph
>>>
>>>
>>> How about this:
>>>
>>>
>>>
>>> > DF[sapply(strsplit(as.character(DF$V3), ":"),
>>> function(i) all(as.numeric(i) <= 10)), ]
>>> V1 V2 V3
>>> 2 d f 1:2:1
>>> 3 c d 1:0:9
>>>
>>>
>>> Basically, use strsplit() to break apart 'V3':
>>>
>>> > strsplit(as.character(DF$V3), ":")
>>> [[1]]
>>> [1] "0" "1" "12"
>>>
>>> [[2]]
>>> [1] "1" "2" "1"
>>>
>>> [[3]]
>>> [1] "1" "0" "9"
>>>
>>>
>>> The use sapply() to crawl the list, converting the elements to numerics
>>> and do the value comparison:
>>>
>>> > sapply(strsplit(as.character(DF$V3), ":"),
>>> function(i) all(as.numeric(i) <= 10))
>>> [1] FALSE TRUE TRUE
>>>
>>>
>>> The above then returns the logical vector to subset the rows of 'DF'.
>>>
>>> HTH,
>>>
>>> Marc Schwartz
>>>
>>>
>>>
>>> [[alternative HTML version deleted]]
>>>
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>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
>
>
--
Stephen Sefick
Research Scientist
Southeastern Natural Sciences Academy
Let's not spend our time and resources thinking about things that are
so little or so large that all they really do for us is puff us up and
make us feel like gods. We are mammals, and have not exhausted the
annoying little problems of being mammals.
-K. Mullis
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