# Régions englobantes

Calculer l’enveloppe convexe, la forme alpha ou les limites autour des points

Créez des régions définies par des limites qui englobent un ensemble de points. La fonction `boundary` permet de spécifier l’étroitesse de l’ajustement autour des points, tandis que les fonctions `convhull` et `convhulln` renvoient la plus petite limite convexe. Les objets `alphaShape` proposent des paramètres de limite ajustables basés sur le rayon alpha ainsi que des fonctions d’objet pour calculer des quantités géométriques.

## Fonctions

développer tout

 `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.