[R] Using lapply and list names not available

[Dimitris Rizopoulos]

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maybe you could use mapply(), e.g.,

people <- list(Andrew = rnorm(10), Mary = rnorm(10),
    Jane = rnorm(10), Richard = rnorm(10))


doplot <- function (individual, main) {
    plot(individual, main = main)
}


par(mfrow = c(2,2))
jpeg(file="test.jpg")
mapply(doplot, people, names(people))
dev.off()


I hope it helps.

Best,
Dimitris

----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
     http://www.student.kuleuven.be/~m0390867/dimitris.htm



----- Original Message ----- 
From: "john seers (IFR)" <john.seers at bbsrc.ac.uk>
To: "R Help" <r-help at stat.math.ethz.ch>
Sent: Tuesday, February 05, 2008 5:05 PM
Subject: [R] Using lapply and list names not available


>
> Hello All
>
> Using lapply and ending up with lists of lists I often end up in the
> position of not having the names of the list passed by lapply. So, 
> if I
> am doing something like a plot, and I would like the title to 
> reflect
> which plot it is, I cannot easily do it. So I find myself doing some
> unstructured variable passing and counting to be able to keep track 
> of
> my data. Then I think perhaps I should not use lapply and just use
> simple loops.
>
> Is there a better way to do this?
>
> Here is a simple example to illustrate what I am talking about. The 
> list
> has the names of people and I need the names to use as the headings 
> of
> the plots.
>
>
>
> ########################################################################
> #########
>
> # Make some test data
> people<-list(Andrew=rnorm(10), Mary=rnorm(10), Jane=rnorm(10),
> Richard=rnorm(10))
>
>
> # Function to plot each list entry with its title name
> doplot<-function(individual, peoplenames) {
>    peoplecount<<-peoplecount + 1
>    plot(individual, main=peoplenames[peoplecount])
> }
>
> #
> peoplecount<-0
> jpeg(file="test.jpg")
> par(mfrow=c(2,2))
> lapply(people, doplot, names(people))
> dev.off()
>
> ########################################################################
> #############
>
>
> Thank you for any suggestions.
>
>
> John Seers
>
> ---
>
> ______________________________________________
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> PLEASE do read the posting guide 
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> and provide commented, minimal, self-contained, reproducible code.
> 


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