Quincunx - Examples

Examples

Quincunx patterns occur in many contexts:

• In heraldry, groups of five elements (charges) are often arranged in a quincunx pattern, called in saltire in heraldic terminology. The flag of the Solomon Islands features this pattern, with its five stars representing the five main island groups in the Solomon Islands. Another instance of this pattern occurs in the flag of the Republic of Yucatán, where it symbolized the five departments into which the republic was divided.
• A quincunx is a standard pattern for planting an orchard.
• Quincunxes are used in modern computer graphics as a pattern for multisample anti-aliasing. Quincunx antialiasing samples scenes at the corners and centers of each pixel. These five sample points, in the shape of a quincunx, are combined to produce each displayed pixel. However, samples at the corner points are shared with adjacent pixels, so the number of samples needed is only twice the number of displayed pixels.
• In numerical analysis, the quincunx pattern describes the two-dimensional five-point stencil, a sampling pattern used to derive finite difference approximations to derivatives.
• In architecture, a quincuncial plan, also defined as a "cross-in-square", is the plan of an edifice composed of nine bays. The central and the four angular ones are covered with domes or groin vaults so that the pattern of these domes forms a quincunx; the other four bays are surmounted by barrel vaults.
• A quincunx is one of the quintessential designs of Cosmatesque inlay stonework.
• A quincuncial map is a conformal map projection that maps the poles of the sphere to the centre and four corners of a square, thus forming a quincunx.
• The points on each face of a unit cell of a face-centred cubic lattice form a quincunx.
• The quincunx as a tattoo is known as the five dots tattoo. It has been variously interpreted as a fertility symbol, a reminder of sayings on how to treat women or police, a recognition symbol among the Romani people, a group of close friends, standing alone in the world, or time spent in prison (with the outer four dots representing the prison walls and the inner dot representing the prisoner). Thomas Edison, whose many inventions included a tattooing machine, had this pattern tattooed on his forearm.
• Republican Roman manipular legions adoped a checkered formation called quincunx when deployed for battle.