13  anylist

Function spatstat.geom::anylist() creates a list of objects of any type, i.e., an R object of S3 class 'anylist', which inherits from the class 'listof' defined in package stats shipped with R version 4.5.2 (2025-10-31).

Listing 13.1, Listing 13.2 summarize the S3 methods for the class 'anylist' in the spatstat.* family of packages,

Listing 13.1: Existing S3 methods spatstat.geom::*.anylist

suppressPackageStartupMessages(library(spatstat.geom))
.S3methods(class = 'anylist', all.names = TRUE) |> 
  attr(which = 'info', exact = TRUE) |>
  subset.data.frame(subset = from == 'spatstat.geom')
#                       visible          from       generic  isS4
# [.anylist                TRUE spatstat.geom             [ FALSE
# [<-.anylist              TRUE spatstat.geom           [<- FALSE
# as.hyperframe.anylist    TRUE spatstat.geom as.hyperframe FALSE
# plot.anylist             TRUE spatstat.geom          plot FALSE
# print.anylist            TRUE spatstat.geom         print FALSE
# summary.anylist          TRUE spatstat.geom       summary FALSE

Listing 13.2: Existing S3 methods spatstat.explore::*.anylist

suppressPackageStartupMessages(library(spatstat.explore))
.S3methods(class = 'anylist', all.names = TRUE) |> 
  attr(which = 'info', exact = TRUE) |>
  subset.data.frame(subset = from == 'spatstat.explore')
#                  visible             from  generic  isS4
# collapse.anylist    TRUE spatstat.explore collapse FALSE
# pool.anylist        TRUE spatstat.explore     pool FALSE

---

The examples in Chapter 13 require that the search path contains the following namespaces,

library(groupedHyperframe)

---

Package groupedHyperframe (v0.3.2) implements more S3 methods to the class 'anylist' (Table 13.1),

Table 13.1: S3 methods groupedHyperframe::*.anylist (v0.3.2)

	visible	generic	isS4
kerndens.anylist	TRUE	groupedHyperframe::kerndens	FALSE
quantile.anylist	TRUE	stats::quantile	FALSE

13.1 Kernel Density Estimates of numeric-vectors

The S3 method kerndens.anylist() (Listing 13.3) finds the kernel densitys of each numeric-vector member of an anylist.

Listing 13.3: Example: function kerndens.anylist()

set.seed(11); spatstat.geom::anylist(
  rnorm(1e2L),
  rnorm(1e3L)
) |> 
  kerndens(n = 8L)
# [[1]]
# [1] 0.0001485149 0.0279242695 0.2154613160 0.3923521927 0.3012886913 0.1122736307 0.0254082139 0.0002006779
# 
# [[2]]
# [1] 2.058857e-05 7.825877e-03 1.269701e-01 3.611332e-01 2.957708e-01 5.525767e-02 4.282642e-03 2.041884e-05

Listing 13.4 showcases the exception handling of a non-numeric anylist.

Listing 13.4: Exception: function kerndens.anylist(), no numeric-vector member

spatstat.data::Kovesi$values |> 
  kerndens() |>
  is.null()
# [1] TRUE

13.2 Quantile of numeric-vectors

The S3 method quantile.anylist() (Listing 13.5) finds the quantiles of each numeric-vector member of an anylist.

Listing 13.5: Example: function quantile.anylist()

set.seed(11); spatstat.geom::anylist(
  rnorm(1e2L),
  rnorm(1e3L)
) |> 
  quantile()
# [[1]]
#         0%        25%        50%        75%       100% 
# -2.1867814 -0.8209852 -0.1868264  0.5014134  2.3396931 
# 
# [[2]]
#           0%          25%          50%          75%         100% 
# -3.276987817 -0.628120701  0.007994794  0.669427485  3.699685561

Listing 13.6 showcases the exception handling of a non-numeric anylist.

Listing 13.6: Exception: function quantile.anylist(), no numeric-vector member

spatstat.data::Kovesi$values |> 
  quantile() |>
  is.null()
# [1] TRUE

13.3 Split

Section 13.3 is intended as an educational handbook for beginners to R version 4.5.2 (2025-10-31) and package spatstat.geom (v3.6.1). This section does not discuss the functionality of package groupedHyperframe (v0.3.2).

The default method of the S3 generic function base::split() splits an anylist into a list of anylist. This feature is made possible by the magic of the S3 method spatstat.geom::`[.anylist`.

Listing 13.7 splits a spatial-object list (solist, Chapter 30) vesicles.extra (Section 10.20) into a list of solist.

Listing 13.7: Review: function base::split.default() on solist

v1 = spatstat.data::vesicles.extra |>
  split.default(f = factor(c('a', 'a', 'b', 'b')))
v2 = spatstat.data::vesicles.extra |>
  split(f = factor(c('a', 'a', 'b', 'b')))
stopifnot(identical(v1, v2))

Listing 13.8 splits a pixel-image-object list (imlist, Chapter 23) gorillas.extra (Section 10.12) into a list of imlist.

Listing 13.8: Review: function base::split.default() on imlist

g1 = spatstat.data::gorillas.extra |>
  split.default(f = factor(c('a', 'a', 'b', 'b', 'c', 'c', 'c')))
g2 = spatstat.data::gorillas.extra |>
  split(f = factor(c('a', 'a', 'b', 'b', 'c', 'c', 'c')))
stopifnot(identical(g1, g2))

Listing 13.9 splits a point-pattern-object list (ppplist, Chapter 28) waterstriders (Section 10.21) into a list of ppplist.

Listing 13.9: Review: function base::split.default() on ppplist

w1 = spatstat.data::waterstriders |>
  split.default(f = factor(c('a', 'a', 'b')))
w2 = spatstat.data::waterstriders |>
  split(f = factor(c('a', 'a', 'b')))
stopifnot(identical(w1, w2))