Voronoi Geom

Wiki ▸ API Reference ▸ Geometry ▸ Voronoi Geom

Voronoi layouts are particularly useful for invisible interactive regions, as demonstrated in Nate Vack’s Voronoi picking example. See Tovi Grossman’s paper on bubble cursors for a related concept.

# d3.geom.voronoi()

Creates a Voronoi layout with default accessors.

# voronoi(data)

Returns an array of polygons, one for each input vertex in the specified data array. Each polygon is an array of points, and each point is a two-element array of x and y positions.

If any vertices are coincident or have NaN positions, the behavior of this method is undefined: most likely, invalid polygons will be returned! You should filter invalid vertices, and consolidate coincident vertices, before calling this function.

# voronoi.x([x])

If x is specified, sets the x-coordinate accessor. If x is not specified, returns the current x-coordinate accessor, which defaults to:

function(d) { return d[0]; }

# voronoi.y([y])

If y is specified, sets the y-coordinate accessor. If y is not specified, returns the current y-coordinate accessor, which defaults to:

function(d) { return d[1]; }

# voronoi.clipExtent([extent])

If extent is specified, sets the clip extent of the Voronoi layout to the specified bounds and returns the layout. The extent bounds are specified as an array [​[x0, y0], [x1, y1]​], where x0 is the left side of the extent, y0 is the top, x1 is the right and y1 is the bottom. If extent is null, no clipping is performed. If extent is not specified, returns the current clip extent which defaults to null.

See this example. Use of a clip extent is strongly recommended, as unclipped polygons may have large coordinates which do not display correctly.

Alternatively, you can also employ custom clipping without specifying a size, either in SVG or by post-processing with polygon.clip.

# voronoi.links(data)

Returns the Delaunay triangulation of the specified data array as an array of links. Each link has the following attributes:

• source - the source node (an element in data).
• target - the target node (an element in data).

The Force-Directed States of America uses an array of such links to create a force-directed graph.

# voronoi.triangles(data)

Returns the Delaunay triangulation of the specified data array as an array of triangles. Each triangle is a three-element array containing elements from data.