plot_ntl_panel: Plot a multi-year nighttime lights panel

In lightson: Download and Analyse Nighttime Lights Satellite Data

Plot a multi-year nighttime lights panel

Description

Arranges one map per year into a patchwork grid with a shared title, subtitle, and caption. A shared radiance scale is computed from the 99.5th percentile across all rasters so panels are directly comparable.

Usage

plot_ntl_panel(
  rasters,
  polygons = NULL,
  title = "India at night",
  subtitle = NULL,
  caption = NULL,
  palette = c("glow", "bhuvan"),
  ncol = 3L,
  bg_colour = "#080c14",
  title_colour = "#CDD9E5",
  subtitle_colour = "#8B949E",
  year_colour = "#E8A87C"
)

Arguments

rasters	Named list of SpatRaster objects as returned by ntl_download() or bhuvan_raster(), keyed by year.
polygons	Optional sf object for boundary overlay.
title	Overall plot title. Default "India at night".
subtitle	Optional subtitle string.
caption	Optional caption string.
palette	One of "glow" (default) or "bhuvan". Passed to plot_ntl_map().
ncol	Number of columns in the grid. Default 3.
bg_colour	Background colour of the assembled panel. Default "#080c14" (deep navy).
title_colour	Title text colour. Default "#CDD9E5".
subtitle_colour	Subtitle and caption text colour. Default "#8B949E".
year_colour	Year label colour on each individual map. Default "#E8A87C" (warm amber).

Details

Requires the patchwork package.

Value

A patchwork object.

Examples

r <- terra::rast(
  nrows = 20, ncols = 20, xmin = 77, xmax = 78, ymin = 28, ymax = 29,
  crs = "EPSG:4326", vals = seq_len(400) / 2
)
plot_ntl_panel(list("2020" = r, "2021" = r * 1.2), title = "Synthetic example")

lightson documentation built on Nov. 3, 2026, 5:07 p.m.