ggsave_inset: Save a composed inset plot with appropriate dimensions

Description

A wrapper around ggplot2::ggsave() that automatically calculates the output dimensions based on the full ratio defined in the inset configuration. This ensures the saved image maintains the correct aspect ratio for proper rendering of all subplots.

Usage

ggsave_inset(
  filename,
  plot = last_plot(),
  device = NULL,
  path = NULL,
  scale = 1,
  width = NA,
  height = NA,
  ...,
  ratio_scale = 1,
  .cfg = last_insetcfg()
)

Value

NULL (invisibly). Saves the plot to disk.

Arguments

filename: Filename to save the plot to. Passed directly to ggplot2::ggsave().
plot: The plot to save. Default ggplot2::last_plot().
device: Device to save to (e.g., "png", "pdf"). Default NULL (inferred from filename).
path: Directory path for saving. Default NULL (current directory).
scale: Scaling factor. Default 1.
width, height: Width and height in inches. You only need to provide one; the other will be calculated automatically. Default NA.
...: Additional arguments passed to ggplot2::ggsave().
ratio_scale: Optional scaling factor to adjust the aspect ratio. Default 1.0. Use when there are extra elements (e.g., titles, legends) that affect the overall image dimensions. For example, set to 1.1 for extra width when a legend is present on the left/right side.
.cfg: An inset configuration (class insetcfg) created by config_insetmap().

Details

All parameters are the same as ggplot2::ggsave(), except that you only need to provide either width or height, and the other dimension will be calculated automatically to match the aspect ratio defined in the inset configuration.

The function automatically calculates width and height based on .cfg$main_ratio to maintain aspect ratio consistency. If both width and height are provided, a warning is issued as the output aspect ratio may not match the configuration.

Examples

Run this code

library(sf)
library(ggplot2)

nc <- sf::st_read(system.file("shape/nc.shp", package = "sf"), quiet = TRUE)

config_insetmap(
    bbox = st_bbox(nc),
    specs = list(
        inset_spec(main = TRUE),
        inset_spec(
            xmin = -84, xmax = -75, ymin = 33, ymax = 37,
            loc = "left bottom", width = 0.3
        )
    )
)

base <- ggplot(nc, aes(fill = AREA)) +
    geom_sf() +
    scale_fill_viridis_c() +
    guides(fill = "none") +
    theme_void()
with_inset(base)

# Save with automatically calculated height

ggsave_inset(paste0(tempdir(), "/inset_map.png"), width = 10)