d3 + TopoJSON

100%

✓ Published0🌍 Public

Last edited Nov 4, 2016

Created on Nov 4, 2016

This example displays a map of U.S. counties rendered as SVG paths, with each county filled in light gray and outlined in white. Hovering over a county turns it red. The visualization loads a TopoJSON file from a GitHub gist, converts it to GeoJSON using the `topojson.feature` method, and draws the features with `d3.geo.path()` in D3 v3. The map uses the default projection provided by D3’s geographic path generator.

AI-generated description

Working with TopoJSON and d3.js projections for mapping geospatial data.

forked from <a href='http://bl.ocks.org/mbostock/'>mbostock</a>'s block: <a href='http://bl.ocks.org/mbostock/4122298'>U.S. Counties TopoJSON</a>

gpl-3.0 Licensed

Similar vizzes

Loading thumbnail…

d3 + TopoJSON

This example shows a map of U.S. counties rendered as gray SVG paths with white borders, which turn red on hover. It loads a TopoJSON file from a gist and converts it to GeoJSON using `topojson.feature`, then projects and draws each county with `d3.geo.path()`. The code relies on d3.v3 and TopoJSON v1, and the map uses a default projection without custom zoom or interaction.

AAlan McConchie

97% match

Loading thumbnail…

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

90% match

Loading thumbnail…

Gist 5967514

This example displays a map of U.S. counties using a TopoJSON shapefile from the U.S. Census Bureau, rendered as gray-filled paths with white borders that turn red on hover. It shows the geographic boundaries of counties and responds to clicks, though the click behavior only logs to the console. The visualization uses D3 v3’s `d3.geo.path()` to project and draw the SVG paths, and TopoJSON’s `topojson.feature` to extract GeoJSON features from the topology. The map is static, with no zoom or pan, and the hover effect is the only interactive styling.

CCaged

90% match

Loading thumbnail…

Let's make a map US-counties with D3.js!

This example renders a choropleth-style map of all US counties as light green SVG paths with subtle black borders. It uses D3 v5’s `geoAlbersUsa` projection and `geoPath` generator to convert TopoJSON county boundaries from the `us-atlas` dataset into scalable vector graphics. The code loads the TopoJSON via `d3.json`, extracts features with `topojson.feature`, and binds them to SVG path elements, while styling is handled with CSS class selectors.

NNita

88% match

Loading thumbnail…

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.

Mmbostock

88% match

Loading thumbnail…

Untitled

This example displays a choropleth map of the United States with counties rendered as SVG paths, filled in light gray and highlighted in light blue on hover. The code loads a TopoJSON file of US counties from a remote GitHub repository and uses `d3.geo.mercator` with a fitted projection to size and position the map within the viewport. Counties are drawn via `d3.geo.path`, and the script references an additional tooltip feature using `d3.tip` in the accompanying test.js file, though that tooltip is not implemented in the visible code. The map is rendered entirely with D3 v3 and SVG.

AAnnie Ulichney

88% match

Loading thumbnail…

Let's make a map of US-counties with D3.js:"hover and county name "

This example displays an interactive map of U.S. counties rendered as SVG paths, with each county’s name appearing as a tooltip on hover. The map uses the `geoAlbersUsa` projection and `geoPath` from D3 v5, while TopoJSON’s `feature` method extracts county geometries from the us-atlas counties-10m.json dataset. Hovering highlights the county in green via a CSS `:hover` rule. The visualization depends on D3’s `select` and `json` utilities to fetch and bind the geographic data.

NNita

87% match

Loading thumbnail…

Let's make a map of US-counties with D3.js:"hover and county name "

This example displays a choropleth-style map of all US counties rendered as SVG paths, with county names revealed on hover via a native `<title>` element. The visualization uses D3 v5’s `geoAlbersUsa` projection and `geoPath` to draw county boundaries from TopoJSON data loaded from the us-atlas package. County shapes are styled with black strokes and a green fill on mouseover, showing the geographic distribution of administrative divisions. The code filters the TopoJSON for county features and binds them to path elements, relying on the browser’s built-in tooltip behavior for the name display.

NNita

87% match