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In geometry, the density of a polytope represents the number of windings of a polytope, particularly a uniform or regular polytope, around its center. It can be visually determined by counting the minimum number of facet or face crossings of a ray from the center to infinity. The density is constant across any continuous interior region of a polytope that crosses no facets. For a non-self-intersecting (acoptic) polytope, the density is 1. Tessellations with overlapping faces can similarly define density as the number of coverings of faces over any given point.〔Coxeter, H. S. M; ''The Beauty of Geometry: Twelve Essays'' (1999), Dover Publications, , ISBN 0-486-40919-8 (206–214, Density of regular honeycombs in hyperbolic space)〕 ==Polygons== The density of a star polygon is the number of times that the polygonal boundary winds around its center; it is the winding number of the boundary around the central point. For a regular star polygon , the density is ''q''. It can be visually determined by counting the minimum number of edge crossings of a ray from the center to infinity. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Density (polytope)」の詳細全文を読む スポンサード リンク
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