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Negative correlation can be seen geometrically when two normalized random vectors are viewed as points on a sphere, and the correlation between them is the cosine of the circular arc of separation of the points on a great circle of the sphere. [1] When this arc is more than a quarter-circle (θ > π/2), then the cosine is negative.
In a 3-dimensional projective space a correlation maps a point to a plane. As stated in one textbook: [2] If κ is such a correlation, every point P is transformed by it into a plane π′ = κP, and conversely, every point P arises from a unique plane π′ by the inverse transformation κ −1.
In geometry, many uniform tilings on sphere, euclidean plane, and hyperbolic plane can be made by Wythoff construction within a fundamental triangle, (p q r), defined by internal angles as π/p, π/q, and π/r.
Terms such as correlation diagram(s), diagram(s) of correlation, and the like may refer to: Data visualization, the general process of presenting information visually; Statistical graphics, images depicting statistical information; In chemistry, there are several types of correlation diagrams:
An exception are the spin representation of SO(3): strictly speaking these are representations of the double cover SU(2) of SO(3). In turn, SU(2) is identified with the group of unit quaternions, and so coincides with the 3-sphere. The spaces of spherical harmonics on the 3-sphere are certain spin representations of SO(3), with respect to the ...
A function is a semivariogram if and only if it is a conditionally negative definite function, i.e. for all weights , …, subject to = = and locations , …, it holds: ∑ i = 1 N ∑ j = 1 N w i γ ( s i , s j ) w j ≤ 0 {\displaystyle \sum _{i=1}^{N}\sum _{j=1}^{N}w_{i}\gamma (\mathbf {s} _{i},\mathbf {s} _{j})w_{j}\leq 0}
The only regular (of class C 2) closed surfaces in R 3 with constant positive Gaussian curvature are spheres. [2] If a sphere is deformed, it does not remain a sphere, proving that a sphere is rigid. A standard proof uses Hilbert's lemma that non-umbilical points of extreme principal curvature have non-positive Gaussian curvature. [3]
Walsh diagrams in conjunction with molecular orbital theory can also be used as a tool to predict reactivity. By generating a Walsh Diagram and then determining the HOMO/LUMO of that molecule, it can be determined how the molecule is likely to react. In the following example, the Lewis acidity of AH 3 molecules such as BH 3 and CH 3 + is predicted.