[R] Using lapply and list names not available

[Gabor Grothendieck]

The problem is your data is in wide format and you want it in long format.
See ?reshape and also see the reshape package.   In your example, ?stack
is sufficient:

library(lattice)
xyplot(values ~ seq_along(values) | ind, data = stack(people))


On Feb 5, 2008 11:05 AM, john seers (IFR) <john.seers at bbsrc.ac.uk> wrote:
>
> 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
>
> ---
>
> ______________________________________________
> 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.
>