The Peirce quincuncial projection is the conformal map projection from the sphere to an unfolded square dihedron, developed by Charles Sanders Peirce in 1877. Each octant projects onto an isosceles ri
Using the Peirce quincuncial projection to present a spherical panorama.
"The World on a Quincuncial Projection", from Peirce (1879) "A Quincuncial Projection of the Sphere". American Journal of Mathematics, 2 (4): 394–397
Quincunx
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A quincunx is a geometric pattern consisting of five points arranged in a cross, with four of them forming a square or rectangle and a fifth at its center. The same pattern has other names, including
Peirce quincuncial projection
…into a square. The name quincuncial refers to this arrangement: the north pole at the center and quarters of the south pole in the corners form a quincunx pattern like the pips on the five face of a traditional die. The projection has the distinctive property that it forms a seamless square tiling of the…
A quincunx of pips on the five-side of a die
A quincunx coin
12th-century Cosmatesque mosaic in the Cappella Palatina, Palermo, Sicily