Package index • explodemap

Core workflow

Main entry points for generating two-level exploded-view maps from projected sf data or state-level TIGER/Line inputs.

explode_sf(): Explode any sf object with an existing grouping column
explode_sf_with_lookup(): Explode any sf object using an external lookup table
explode_state(): Explode a US state from TIGER/Line data

Interactive focus maps

htmlwidgets and Shiny helpers for selected-feature focus, labels, and non-blocking information cards.

explode_section(): Explode one selected section and keep the rest as context
focus_map() focusmapOutput() renderFocusmap(): Interactive focus-map viewer
focus_map_preset(): Focus-map option presets
focusMapProxy() update_focus_labels() update_focus_palette() update_focus_data(): Focus-map Shiny proxy

Grouped layouts

Functions for three-level grouped layouts with anchor placement and optional collision-aware refinement.

explode_grouped(): Create a three-level grouped exploded map
layout_regions(): Compute region anchor positions for grouped layouts
estimate_block_radii(): Estimate block radius for each region

State-first composition (dragmapr bridge)

Hand a computed layout to the dragmapr editor as a reusable dragmapr_state, then apply edited compositions back. as_dragmapr_state() is the preferred handoff; the resulting state is accepted by focus_map(), render_dragged_map(), and update_exploded_layout(). as_dragmapr() is the legacy low-level handoff.

as_dragmapr_state(): Convert a grouped layout to a dragmapr editing state
update_exploded_layout(): Update an exploded grouped layout after manual composition
as_dragmapr(): Convert a grouped layout to a drag-edit handoff object (legacy)

Input preparation and app primitives

Reusable validation, simplification, grouping, palette, and fingerprint helpers that support Shiny apps, examples, and preprocessing pipelines.

validate_explodemap_input(): Validate explodemap input
prepare_explodemap_input(): Prepare input for grouped explodemap layouts
count_geometry_vertices(): Count geometry vertices
simplify_to_vertex_budget(): Simplify geometry to a vertex budget
assign_spatial_groups(): Assign generated spatial groups
group_palette(): Create a stable group palette
explodemap_fingerprint(): Fingerprint explodemap geometry and grouping

Layout quality and optimization

Score a grouped layout and search for better region placements.

diagnose_layout(): Diagnose grouped layout quality
plot(<layout_quality_report>): Plot a grouped-layout diagnostic
layout_objective(): Build layout objective weights
optimize_grouped_layout(): Search grouped-layout parameters

Statistics and calibration

Tools for computing geometry statistics, deriving parameters, and building calibration summaries across datasets.

compute_stats(): Compute geometry statistics for parameter derivation
derive_params(): Derive displacement parameters from geometry statistics
calibration_row(): Extract calibration row from an exploded_map

Export and cache helpers

Optional export helpers and cache management utilities.

export_topojson(): Export an exploded map as TopoJSON
apply_region_offsets(): Apply documented display offsets by region
read_drag_offsets(): Read drag-helper offset CSVs into a region offset data frame
cache_list(): List cached datasets
cache_clear(): Clear explodemap download cache

HHS reference maps

Ready-made U.S. Department of Health and Human Services region layouts, palettes, and a one-call focus map for HHS-style placeholder shapes.

hhs_layout(): Build an HHS reference layout
hhs_focus_map(): Create a focus-map widget for HHS regions
as_hhs_states(): Standardize state polygons for HHS reference maps
hhs_regions(): HHS regional assignments for states and territories
hhs_region_names(): HHS region display names
hhs_display_offsets(): HHS reference-layout display offsets
hhs_palette(): HHS region colour palette

Methods

S3 methods for printing, plotting, summarising, and extracting tabular results from exploded map objects.

print(<exploded_map>): Print an exploded_map object
plot(<exploded_map>): Plot an exploded_map object
summary(<exploded_map>): Summary of an exploded_map object
print(<grouped_exploded_map>): Print a grouped_exploded_map object
plot(<grouped_exploded_map>): Plot a grouped_exploded_map object
summary(<grouped_exploded_map>): Summary of a grouped_exploded_map object