SepTest (version 0.0.1)

plot_procedures: Plot original vs permuted time ordering

Description

Produces a side-by-side plot comparing the temporal component of an original spatio-temporal point pattern with that of a permuted (or block-permuted) version. This graphical diagnostic is intended to assess the effect of temporal reordering procedures used in separability tests.

Usage

plot_procedures(
  original,
  permuted,
  title = "Permutation",
  col = c("blue", "red"),
  pch = 1,
  ...
)

Value

The function is invoked for its side effect of producing a plot and returns no value.

Arguments

original

A matrix or data frame with at least three columns \((x,y,t)\). The time coordinate is taken from column 3.

permuted

A matrix or data frame with the same structure as original. The time coordinate is taken from column 3.

title

Character string; title for the permuted panel.

col

Character vector of length 2 giving colors for the original and permuted panels.

pch

Plotting character passed to plot.

...

Further graphical parameters passed to plot.

Author

Nafiseh Vafaei

Details

The function is commonly employed to visualize temporal permutations generated by procedures such as sim.procedures or block.permut, which underpin pure and block permutations-based inference for first-order separability (see Ghorbani et al., 2021, Section 3.2).

The function uses base R graphics to display two panels:

1. The temporal ordering of the original point pattern.

2. The temporal ordering after permutation or block permutation.

This diagnostic is particularly useful when validating permutation-based inference procedures such as chi2.test, dHS.test, and global.envelope.test.

References

Ghorbani, M., Vafaei, N., Dvořák, J., & Myllymäki, M. (2021). Testing the first-order separability hypothesis for spatio-temporal point patterns. Computational Statistics & Data Analysis, 161, 107245.

See Also

sim.procedures, block.permut, dHS.test, chi2.test

Examples

set.seed(123)
X <- cbind(x = runif(20), y = runif(20),
           time = seq(0, 1, length.out = 20))

# Example: visualize pure permutation
sim_pure <- sim.procedures(X, nperm = 1, method = "pure")[[1]]
plot_procedures(X, sim_pure, title = "Pure Permutation")

# Example: visualize block permutation (requires Block_permutation)
if (requireNamespace("combinat", quietly = TRUE)) {
  sim_block <- block.permut(nblocks = 4, X = X, nperm = 1)[[1]]
  plot_procedures(X, sim_block, title = "Block Permutation")
}