[R] Probably dumb question about lists

[Boris Steipe]

plot.tile.list() expects its argument to be of class tile.list, and to have an attribute "rw", both of which are not conserved after subsetting. You can do ...


if (!require(deldir)) {
  install.packages("deldir")
  library(deldir)
}
x <- rnorm(10)
y <- rnorm(10)
del <- deldir(x, y)
tl <- tile.list(del)

tl2 <- tl[1:4]
class(tl2) <- "tile.list"
attr(tl2, "rw") <- attr(tl, "rw")
plot.tile.list(tl2)  # or just plot(tl2)

BUT!
This doesn't really make sense because you are just "randomly" plotting some tiles from the full triangulation, not plotting a triangulation with less points. That would be:

plot(tile.list(deldir(x[1:4], y[1:4])))

Cheers,
B.




On Jan 14, 2015, at 10:13 AM, Bert Gunter <gunter.berton at gene.com> wrote:

> 1. Please in future specify the package (deldir here) that contains
> the functions you refer to.
> 
> 2. **Always** first try ?str before posting queries like this, as this
> will often reveal the problem.
> 
> str(tl[1:800])
> 
> 3. I would **guess** (ergo could well be wrong) that "[" is not
> preserving the class attribute of tl. Ergo you are getting the basic
> plot method and not the plot.tile.list method.
> 
> HTH.
> 
> Cheers,
> 
> Bert
> 
> Bert Gunter
> Genentech Nonclinical Biostatistics
> (650) 467-7374
> 
> "Data is not information. Information is not knowledge. And knowledge
> is certainly not wisdom."
> Clifford Stoll
> 
> 
> 
> 
> On Wed, Jan 14, 2015 at 6:23 AM, Raphael Päbst <raphael.paebst at gmail.com> wrote:
>> Hello everybody!
>> I feel very stupid right now but suspect it has something to do with
>> tiredness. I am trying to drop the last couple of Elements from a list
>> and this doesn't work as expected.
>> 
>> My code looks something like this:
>> 
>> del <- deldir(x, y)
>> tl <- tile.list(del)
>> plot(tl)
>> 
>> Now, I only want to plot the first 800 elements of tl and can't work
>> out how to do this.
>> plot(tl[1:800])
>> gives me an error "x is a list but does not have components x and y"
>> which somewhat baffles me. I'm sure this is all due to lack of sleep
>> but right now I feel very dumb and would welcome any pointers towards
>> a solution for my problem.
>> 
>> Many thanks!
>> 
>> Raphael
>> 
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> 
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
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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.