# 凸包
> [Wiki](Home) ▸ \[\[API Reference\]\] ▸ \[\[Geometry\]\] ▸ **Hull Geom**
[\#](Hull-Geom#hull) d3.geom.**hull**()
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Create a new hull layout with the default *x*- and *y*-accessors.
[\#](Hull-Geom#_hull) **hull**(*vertices*)
Returns the convex hull for the specified *vertices* array, using the current x- and y-coordinate accessors. The returned convex hull is represented as an array containing a subset of the input vertices, arranged in counterclockwise order (for consistency with [polygon.clip](Polygon-Geom#clip)).
Assumes the *vertices* array is greater than three in length. If *vertices* is of length <= 3, returns \[\].
[\#](Hull-Geom#x) hull.**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]; }
```
[\#](Hull-Geom#y) hull.**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]; }
```