Interactive footprint Sankey viewer

Create a browser-based Sankey viewer from a footprint table, such as the output of compute_footprint(). The viewer includes stage filters, a per-stage node limit controls, a minimum-flow threshold, hover tooltips, click-to-highlight interactions, and SVG download.

Each row is treated as one path through the selected stages, with value_col giving the path size. Rows are summed before plotting, so repeated paths are shown as one flow.

The default stages are origin_area, origin_item, target_item, and target_area; target_fd is appended automatically when present. If columns such as origin_area_name or target_item_name are present, they are used as display labels.

Usage

plot_footprint_sankey(
  footprints,
  stages = NULL,
  value_col = "value",
  label_cols = NULL,
  max_nodes = 10,
  other_label = "Other",
  stage_max_nodes = NULL,
  stage_other_labels = NULL,
  embed_max_nodes = Inf,
  stage_embed_max_nodes = NULL,
  min_share = 0,
  title = "Footprint Sankey Viewer",
  subtitle = NULL,
  value_label = "footprint",
  width = "100%",
  height = 680,
  file = NULL,
  open = FALSE
)

Arguments

footprints

A data frame with footprint paths and a numeric value column.

stages

Character vector of columns to use as Sankey stages. Defaults to the footprint origin and target columns.

value_col

Name of the numeric column containing flow values.

label_cols

Optional named character vector mapping stage columns to display-label columns, for example c(origin_area = "origin_area_name"). When omitted, {stage}_name columns are used where available.

max_nodes

Maximum number of individual nodes to show per stage in the current filtered browser view. Less important nodes are grouped into other_label. Use Inf to show all nodes.

other_label

Label used for grouped nodes when max_nodes is finite.

stage_max_nodes

Optional named numeric vector overriding max_nodes for selected stages, for example c(product = 75, target_area = 12).

stage_other_labels

Optional named character vector overriding other_label for selected stages, for example c(product = "Other products").

embed_max_nodes

Maximum number of individual nodes to embed per stage before writing the viewer. Less important nodes are permanently grouped before serialization, reducing file size. Use Inf to keep all nodes available to the browser.

stage_embed_max_nodes

Optional named numeric vector overriding embed_max_nodes for selected stages.

min_share

Minimum visible path size as a percentage of the current filtered total. Set to 0 to keep diffuse trade links visible. Users can change this in the browser.

title

Optional viewer title.

subtitle

Optional viewer subtitle.

value_label

Label used in tooltips and the summary line.

width

Viewer width as a CSS value.

height

Sankey SVG height in pixels.

file

Optional path to write a standalone HTML viewer.

open

If TRUE and file is supplied, open the written viewer in the default browser. If TRUE and file is NULL, a temporary HTML file is written and opened.

Value

A browsable HTML object when file is NULL and open is FALSE; otherwise invisibly returns the HTML file path.

Examples

footprints <- tibble::tribble(
  ~origin_area, ~origin_item, ~target_item, ~target_area, ~value,
  "Brazil", "Soybeans", "Pigmeat", "China", 10,
  "Brazil", "Soybeans", "Milk", "China", 4,
  "Brazil", "Soybeans", "Soybean Oil", "France", 3
)

if (
  interactive() &&
    requireNamespace("htmltools", quietly = TRUE) &&
    requireNamespace("jsonlite", quietly = TRUE)
) {
  plot_footprint_sankey(footprints)
}