County Topology

County Topology

This graph displays the topology of U.S. counties, with each node positioned at its county centroid and links connecting neighboring counties that share a border. The visualization uses TopoJSON’s `topojson.neighbors` to identify adjacent counties and `d3.geoPath` to compute centroids from simplified geometry. A background map and white county mesh provide geographic context, while black lines trace the adjacency network. The code loads data from the us-10m.v1.json file and renders entirely in SVG using D3 v4.

FFrissAnalytics

94% match

U.S. Counties TopoJSON

This map displays the boundaries of every county in the United States using data from a TopoJSON file fetched from `https://d3js.org/us-10m.v1.json`. It renders the county shapes as filled SVG paths, with a white mesh overlay showing county borders via `topojson.mesh`. Hovering over any county turns it red. The visualization is built with D3 v4, using `d3.geoPath` to project the geometry and `topojson.feature` to extract the features, relying on the `us-atlas` TopoJSON data source.

85% match

U.S. Counties TopoJSON Mesh

This example renders a minimalist map of U.S. counties using a TopoJSON mesh from the U.S. Census Bureau’s shapefile, served via the `us-10m.v1.json` file. The SVG visualization displays county boundaries as thin black lines with rounded joins, and overlays small circles at each arc’s starting point, revealing the topological structure of the data. The code uses `d3.geoPath` to project the mesh and `topojson.mesh` to extract boundaries, while `topojson.transform` positions the circles. Rendering is entirely SVG-based with D3 v4, and the map uses no fill, focusing purely on geometric outlines.

83% match

U.S. Counties TopoJSON Mesh

This example displays a mesh of U.S. county boundaries derived from a TopoJSON shapefile, rendered as a black outline with small circles marking each polygon’s coordinate origin. It uses d3.json to load the TopoJSON data, then topojson.mesh and topojson.transform to build the mesh and map coordinates. The outline is drawn with d3.geoPath, while circles are positioned using the transform function, showing the raw geometry structure rather than a filled choropleth. The data comes from the U.S. Census Bureau via the us-10m.v1.json file, and the visualization renders entirely in SVG.

FFrissAnalytics

82% match

County Circles

This symbol map displays every U.S. county as a circle centered on its geographic centroid, with the circle’s radius scaled so its area matches the county’s actual land area. The visualization encodes area quantitatively through the circle size, using a stroke-only rendering in steelblue against a white background. The code loads TopoJSON county boundaries from a remote gist, converts them to GeoJSON with `topojson.feature`, and positions each circle via `d3.geo.path().centroid`. Circle radii are computed from `path.area` using the square-root formula for proportional area scaling, all rendered as SVG elements with d3.v3.

USTopoJSON

This example displays a map of all U.S. counties as thin black outlines, drawn with SVG paths using the `d3.geo.path()` projection. The map is built from a TopoJSON file fetched from a gist, which contains the county geometries. When a user hovers over a county, the CSS `path:hover` rule turns it red, providing a simple interactive highlight. The code relies on D3 v3 and the `topojson.v1` library to process and render the topology data.

JJn1532

U.S. TopoJSON

This visualization displays U.S. state and county boundaries extracted from a TopoJSON file served from d3js.org. A blurred, semi-transparent silhouette of the nation appears behind a solid white version, creating a subtle depth effect. The code uses d3.geoPath to render the features, while topojson.feature and topojson.mesh convert the TopoJSON data into GeoJSON paths for drawing.

US Counties

This map of US counties displays all county boundaries with a subtle drop-shadow effect. The code uses D3 v4’s `d3.geoAlbersUsa` projection and `d3.geoPath` to render geographic features. It loads TopoJSON from a local `counties.json` file and converts it to GeoJSON via `topojson.feature` and `topojson.mesh`. The visualization plots state borders as a separate mesh, overlays white and blurred nation outlines for depth, and draws each county as an outlined SVG path with thin gray strokes.

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