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# Bounding Regions

Compute convex hull, alpha shape, or boundaries around points

Create regions defined by boundaries that enclose a set of points. The `boundary` function allows you to specify the tightness of the fit around the points, while the `convhull` and `convhulln` functions return the smallest convex boundary. `alphaShape` objects offer adjustable boundary settings based on the alpha radius, and have object functions for computing geometric quantities.

## Fonctions

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 `boundary` Boundary of a set of points in 2-D or 3-D `convhull` Convex hull `convhulln` N-D convex hull
 `alphaShape` Polygons and polyhedra from points in 2-D and 3-D `alphaSpectrum` Alpha values giving distinct alpha shapes `criticalAlpha` Alpha radius defining critical transition in shape `numRegions` Number of regions in alpha shape `inShape` Determine if point is inside alpha shape `alphaTriangulation` Triangulation that fills alpha shape `boundaryFacets` Boundary facets of alpha shape `perimeter` Perimeter of 2-D alpha shape `area` Area of 2-D alpha shape `surfaceArea` Surface area of 3-D alpha shape `volume` Volume of 3-D alpha shape `plot` Plot alpha shape `nearestNeighbor` Determine nearest alpha shape boundary point

## Rubriques

• Computing the Convex Hull

This topic explains several methods for computing the convex hull using `convhull`, `convhulln`, `delaunayTriangulation`, and `alphaShape`.

• Types of Region Boundaries

This topic explains the differences between several types of boundaries that enclose a set of points.