Merging States

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Merging States

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Last edited Feb 9, 2016

Created on Apr 18, 2013

This example demonstrates merging multiple US state polygons into a single shape while removing interior borders, using `topojson.merge` on a filtered set of state geometries. A static map renders all states in gray with white boundary strokes via `d3.geo.path` and an AlbersUSA projection, while selected states appear filled in orange with a black outline. It uses D3 v3 and TopoJSON v1, loading geographic data from a local `us.json` file, and highlights the merged path by filtering geometries against a predefined set of state IDs.

AI-generated description

This demonstrates using topojson.merge, a new feature in TopoJSON 1.6, to merge multiple polygons into a single polygon whilst removing interior borders. (An alternative approach is to draw the polygons twice.)

This example is in response to a Stack Overflow question.

gpl-3.0 Licensed

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