43 `vectorlist` from `anylist`

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These packages (Note 1) are a one-person project undergoing rapid evolution. Backward compatibility (per Hadley Wickham) is provided as a courtesy rather than a guarantee.

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Note

The examples in Chapter 43 require

library(groupedHyperframe)

Package groupedHyperframe (v0.4.0, GPL-2) defines a derived S3 class 'vectorlist', for vector-list, which inherits from the classes 'anylist' (Chapter 15), 'listof' and 'list' and is assigned with additional attributes,

attr(., 'mode'), a character scalar, the storage mode;

Table 43.1 summarizes the S3 methods for the class 'vectorlist' in package groupedHyperframe (v0.4.0, GPL-2),

Table 43.1: S3 methods groupedHyperframe::*.vectorlist (v0.4.0)

	visible	generic	isS4
`print.vectorlist`	FALSE	`base::print`	FALSE
`t.vectorlist`	FALSE	`base::t`	FALSE

43.1 Creation & Print

The function as.vectorlist() inspects whether the input qualifies as a vector-list (Section 43.2), and if true, appends the derived class 'vectorlist' to the returned value.

The S3 method print.vectorlist() prints the vital information of a vector-list.

Listing 43.1 converts the hypercolumn Kovesi$values (Section 10.16) into a character vector-list and prints its vital information.

Listing 43.1: Data: a vectorlist object Kovesi_v

spatstat.data::Kovesi$values |>
  as.vectorlist(mode = 'character')
# A 'vectorlist' of 41 vectors 
# Storage Mode: character 
# Individual Vector Length: 256

Listing 43.2 creates a toy numeric vector-list toy_vecL and prints its vital information. Listing 43.3 prints each of the numeric-vector members in the vector-list toy_vecL.

Listing 43.2: Data: a toy numeric vectorlist

set.seed(12); toy_vecL = replicate(n = 5L, expr = rnorm(n = 6L), simplify = FALSE) |> 
  as.vectorlist(mode = 'numeric')
toy_vecL
# A 'vectorlist' of 5 vectors 
# Storage Mode: numeric 
# Individual Vector Length: 6

Listing 43.3: Review: function print.default() on vectorlist

toy_vecL |>
  print.default()
# [[1]]
# [1] -1.4805676  1.5771695 -0.9567445 -0.9200052 -1.9976421 -0.2722960
# 
# [[2]]
# [1] -0.3153487 -0.6282552 -0.1064639  0.4280148 -0.7777196 -1.2938823
# 
# [[3]]
# [1] -0.77956651  0.01195176 -0.15241624 -0.70346425  1.18887916  0.34051227
# 
# [[4]]
# [1]  0.5069682 -0.2933051  0.2236414  2.0072015  1.0119791 -0.3024592
# 
# [[5]]
# [1] -1.0252448 -0.2673848 -0.1991057  0.1311226  0.1457999  0.3620647
# 
# attr(,"class")
# [1] "vectorlist" "anylist"    "listof"     "list"      
# attr(,"mode")
# [1] "numeric"

43.2 Validity

The function is.vectorlist() inspects whether all elements of an anylist (Chapter 15)

are all atomic vectors;
have identical mode;
have identical length;
have identical attributes, e.g., names, etc.

The hypercolumn Kovesi$values (Section 10.16) qualifies as a 'character' vector-list (Listing 43.4), but not as a 'numeric' vector-list (Listing 43.5).

Listing 43.4: Example: function is.vectorlist()

spatstat.data::Kovesi$values |>
  is.vectorlist(mode = 'character') |>
  stopifnot()

Listing 43.5: Example: function is.vectorlist()

spatstat.data::Kovesi$values |>
  is.vectorlist(mode = 'numeric')
# [1] FALSE

43.3 Transpose

The S3 method t.vectorlist() transposes a vector-list into another vector-list, with the length and lengths of the input swapped. Table 43.2 explains the rational of using the S3 generic function t() (R version 4.5.3 (2026-03-11)).

Table 43.2: Rational of “Transpose”

	`base:::t.default()`	`t.vectorlist()`
Input & Output	`matrix`	`vectorlist`
Swaps	`ncol` & `nrow`	`length` & `lengths`

Listing 43.6 transposes the vector-list in Listing 43.1.

Listing 43.6: Example: function t.vectorlist()

Kovesi_v_t = spatstat.data::Kovesi$values |>
  as.vectorlist(mode = 'character') |> 
  t()
Kovesi_v_t
# A 'vectorlist' of 256 vectors 
# Storage Mode: character 
# Individual Vector Length: 41

The motivation of the derived class 'vectorlist' and the S3 method t.vectorlist() is that calling the S3 method with.hyperframe() (v3.7.3, GPL (>= 2)) repeatedly (Listing 43.7) is slow.

Listing 43.7: Review: function with.hyperframe() (Listing 43.6)

Code

spatstat.data::Kovesi |> 
  spatstat.geom::with.hyperframe(expr = values[1L]) |>
  identical(y = Kovesi_v_t[[1L]]) |>
  stopifnot()
spatstat.data::Kovesi |> 
  spatstat.geom::with.hyperframe(expr = values[2L]) |>
  identical(y = Kovesi_v_t[[2L]]) |>
  stopifnot()
spatstat.data::Kovesi |> 
  spatstat.geom::with.hyperframe(expr = values[256L]) |>
  identical(y = Kovesi_v_t[[256L]]) |>
  stopifnot()

The derived class 'vectorlist' is not supported as a hypercolumn in a hyper data frame (Chapter 26) as of package spatstat.geom v3.7.3, GPL (>= 2). Listing 43.8 calls the S3 method t.vectorlist() explicitly as a workaround before package spatstat.geom (ever) supports the class 'vectorlist'.

Listing 43.8: Workaround: without derived class 'vectorlist' (Listing 43.6)

spatstat.data::Kovesi$values |>
  groupedHyperframe:::t.vectorlist() |>
  identical(y = Kovesi_v_t) |>
  stopifnot()