[R] A programming question - is what I want to do possible in R?
Martin Morgan
mtmorgan at fhcrc.org
Tue Sep 29 18:04:26 CEST 2009
jim holtman wrote:
> Add a dummy argument to the function:
>
>>> randomSamples<-lapply(1:2000,function(dummy){
>> + meta_comp[sample(nrow(meta_comp),nTimes),]})
Or
df = data.frame(x=1:10, y=10:1)
replicate(10, df[sample(nrow(df), 5),], simplify=FALSE)
Martin
>
> On Mon, Sep 28, 2009 at 9:39 PM, ewaters <ewaters at nchecr.unsw.edu.au> wrote:
>> Thanks for your help.
>>
>> Unfortunately when I try it this generates an error as follows:
>>
>>> randomSamples<-lapply(1:2000,function(){
>> + meta_comp[sample(nrow(meta_comp),nTimes),]})
>> Error in FUN(1:2000[[1L]], ...) : unused argument(s) (1:2000[[1]])
>>
>>
>>
>>
>> jholtman wrote:
>>> nTime <- 15 # how many samples to take
>>> randomSamples <- lapply(1:2000, function(){
>>> largeDF[sample(nrow(largeDF), nTimes),]
>>> })
>>>
>>> This will create a list of 2000 dataframes with the samples
>>>
>>> On Sun, Sep 27, 2009 at 10:45 PM, ewaters <ewaters at nchecr.unsw.edu.au>
>>> wrote:
>>>> I have a large data frame, 77 rows, with 10 columns. Each row represents
>>>> a
>>>> unique individual with 10 characteristics, some of which are categorical
>>>> factors and some continuous numeric variables. Each of the ten variables
>>>> is
>>>> important (the 10 columns obviously correspond to the individuals of
>>>> interest). Importantly, this data set represents a population (not
>>>> sample)
>>>> of people with a certain medical condition.
>>>>
>>>> What I want to do is to select 2000 random samples of between 2 and 24
>>>> individuals, preserving all the information.
>>>>
>>>> I can easily write loops that will sample from 1:77 2 - 24 times, what I
>>>> really want to know is there any way to easily link the output of loops
>>>> like
>>>> that to the data set so I don't have to trawl through and do it manually
>>>> 2000 times?
>>>>
>>>> Any advice on whether I should even attempt that in R, or try some sort
>>>> of
>>>> hash table in C or somewhere, would be appreciated.
>>>> --
>>>> View this message in context:
>>>> http://www.nabble.com/A-programming-question---is-what-I-want-to-do-possible-in-R--tp25639955p25639955.html
>>>> Sent from the R help mailing list archive at Nabble.com.
>>>>
>>>> ______________________________________________
>>>> R-help at r-project.org mailing list
>>>> 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.
>>>>
>>>
>>>
>>> --
>>> Jim Holtman
>>> Cincinnati, OH
>>> +1 513 646 9390
>>>
>>> What is the problem that you are trying to solve?
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list
>>> 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.
>>>
>>>
>> --
>> View this message in context: http://www.nabble.com/A-programming-question---is-what-I-want-to-do-possible-in-R--tp25639955p25655666.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> 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.
>>
>
>
>
--
Martin Morgan
Computational Biology / Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N.
PO Box 19024 Seattle, WA 98109
Location: Arnold Building M1 B861
Phone: (206) 667-2793
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