Quick start: Peace Declaration of Hiroshima

This vignette reproduces the figures used in Section 5 of the companion paper, applied to the Peace Declaration of Hiroshima 1947–2025 (the 1950 declaration was not delivered).

library(ljmds)

1. Load the corpus from CSV

d <- ljmds.read.csv("peace_declaration")
dim(d$X)                  # 78 x 95
#> [1] 78 95
range(d$t)                # 1947 2025
#> [1] 1947 2025
head(d$keywords, 10)
#>  [1] "weapon"    "Hiroshima" "world"     "peace"     "people"    "year"     
#>  [7] "war"       "hibakusha" "bombing"   "city"

2. Joint (h, k) selection

A minimal grid is used here so the vignette builds quickly; a finer grid is recommended in practice (e.g., h.grid = c(3, 4, 5, 6, 8, 10, 12, 15, 20)). The trivial k = 2 split is excluded by leaving 2 out of k.grid.

sel <- ljmds.select(d$X, d$t,
                    h.grid = c(8, 12),
                    k.grid = 3:4)
sel$h.hat
#> [1] 8
sel$k.hat
#> [1] 4
sel$S.hat
#> [1] 0.2006104
round(sel$S, 3)
#>        k3    k4
#> h8  0.170 0.201
#> h12 0.146 0.130

3. Run the pipeline at $(k, h) = (4, 8)$

fit <- ljmds.pipeline(d$X, d$t, h = 8, k = 4)

4. Figures from the paper

plot(fit, type = "trajectory")

Cluster centroid trajectories.

plot(fit, type = "dendrogram")

Ward dendrogram on H.

plot(sel)

Silhouette heatmap with maximizer marker.

plot(fit, type = "cmd")

Time-collapsed MDS map.

plot(fit, type = "means")

Class mean occurrence curves.

plot(fit, type = "panels")

Per-class smoothed curves.

A pre-rendered animation ships with the package; locate it with system.file() and view it directly:

gif_path <- system.file("extdata", "peace_declaration.gif",
                        package = "ljmds")
gif_path
#> [1] "C:/Users/ksato/AppData/Local/Temp/RtmpOeJTLU/temp_libpath115442fc12dc/ljmds/extdata/peace_declaration.gif"

browseURL(gif_path)              # open in default browser
# magick::image_read(gif_path)   # or: open in RStudio Viewer

To regenerate the GIF from the fitted object (writes a new file to the current working directory; takes about two minutes), uncomment and run:

# gif <- ljmds.animate(fit, file = "peace_declaration.gif",
#                   trail = 10, fps = 2)