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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.

Functions

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boundaryBoundary of a set of points in 2-D or 3-D
convhullConvex hull
convhullnN-D convex hull
alphaShapePolygons and polyhedra from points in 2-D and 3-D
alphaSpectrumAlpha values giving distinct alpha shapes
criticalAlphaAlpha radius defining critical transition in shape
numRegionsNumber of regions in alpha shape
inShapeDetermine if point is inside alpha shape
alphaTriangulationTriangulation that fills alpha shape
boundaryFacetsBoundary facets of alpha shape
perimeterPerimeter of 2-D alpha shape
areaArea of 2-D alpha shape
surfaceAreaSurface area of 3-D alpha shape
volumeVolume of 3-D alpha shape
plotPlot alpha shape
nearestNeighborDetermine nearest alpha shape boundary point

Topics

  • 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.