[R] Problems when Apply a script to a list

[Joris Meys]

Where exactly did you put the sink() statement? I tried it with a 1000
dataframes and I have no problem whatsoever.

Cheers
Joris

On Fri, Aug 27, 2010 at 6:56 AM,  <EVGTS at aueb.gr> wrote:
> Joris,
> thank you very much for your help.
> It is very helpful for me.
> I still have a problem with sink stack although I put after my last print
> result sink().
> I want to ask you another one question. Do you know how can I have at the
> sink output file a message for which one set of the list are the exact
> results. When I use for instead of apply I had
> cat("\n***********************\nEstimation \n********************\nDataset
> Sim : ",
>          i )
> Thank you in advance
> Evgenia
> Joris Meys writes:
>>
>> Answers below.
>> On Thu, Aug 26, 2010 at 11:20 AM, Evgenia <evgts at aueb.gr> wrote:
>>>
>>> Dear users,
>>> *******I have a function f to simulate data from a model (example below
>>> used
>>> only to show my problems)
>>> f<-function(n,mean1){
>>> a<-matrix(rnorm(n, mean1 , sd = 1),ncol=5)
>>> b<-matrix(runif(n),ncol=5)
>>> data<-rbind(a,b)
>>> out<-data
>>> out}
>>> *********I want to simulate 1000 datasets (here only 5) so I use
>>> S<-list()
>>> for (i in 1:5){
>>> S[[i]]<-f(n=10,mean1=0)}
>>> ******I have a very complicated function  for estimation of a model which
>>> I
>>> want to apply to Each one of the above simulated datasets
>>> fun<-function(data){data<-as.matrix(data)
>>> sink(' Example.txt',append=TRUE)
>>>          cat("\n***********************\nEstimation
>>> \n********************\nDataset Sim : ",
>>>            i )
>>> d<-data%*%t(data)
>>> s<-solve(d)
>>> print(s)
>>> out<-s
>>> out
>>> }
>>> results<-list()
>>> for (i in 1:5){results[[i]]<-fun(data=S[[i]])}
>>>
>>> My questions are:
>>> 1) for some datasets system is computational singular and this causes
>>> execution of the for to stop.By this way I have only results until this
>>> problem happens.How can I pass over the execution for this step and have
>>> results for All other datasets for which function fun is applicable?
>>
>> see ?try, or ?tryCatch.
>> I'd do something in the line of
>> for(i in 1:5){
>>     tmp <- try(fun(data=S[[i]]))
>>     results[[i]] <- ifelse(is(tmp,"try-error"),NA,tmp)
>> }
>> Alternatively, you could also use lapply :
>> results <- lapply(S,function(x{
>>   tmp <- try(fun(data=x))
>>    ifelse(is(tmp,"try-error"),NA,tmp)
>> })
>>>
>>> 2) After some runs to my program, I receive this error message someError
>>> in
>>> sink("output.txt") : sink stack is full . How can I solve this problem,
>>> as I
>>> want to have results of my program for 1000 datasets.
>>
>> That is because you never empty the sink. add sink() after the last
>> line you want in the file. This will empty the sink buffer to the
>> file. Otherwise R keeps everything in the memory, and that gets too
>> full after a while.
>>>
>>> 3) Using for is the correct way to run my proram for a list
>>
>> See the lapply solution.
>>>
>>> Thanks alot
>>> Evgenia
>>> --
>>> View this message in context:
>>> http://r.789695.n4.nabble.com/Problems-when-Apply-a-script-to-a-list-tp2339403p2339403.html
>>> Sent from the R help mailing list archive at Nabble.com.
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>>
>>
>>
>> --
>> Joris Meys
>> Statistical consultant
>> Ghent University
>> Faculty of Bioscience Engineering
>> Department of Applied mathematics, biometrics and process control
>> tel : +32 9 264 59 87
>> Joris.Meys at Ugent.be
>> -------------------------------
>> Disclaimer : http://helpdesk.ugent.be/e-maildisclaimer.php
>
>
>



-- 
Joris Meys
Statistical consultant

Ghent University
Faculty of Bioscience Engineering
Department of Applied mathematics, biometrics and process control

tel : +32 9 264 59 87
Joris.Meys at Ugent.be
-------------------------------
Disclaimer : http://helpdesk.ugent.be/e-maildisclaimer.php