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De Casteljau's Algorithm
In the mathematical field of numerical analysis, De Casteljau's algorithm is a recursive method to evaluate polynomials in Bernstein form or Bézier curves, named after its inventor Paul de Casteljau. De Casteljau's algorithm can also be used to split a single Bézier curve into two Bézier curves at an arbitrary parameter value. Although the algorithm is slower for most architectures when compared with the direct approach, it is more numerically stable. Definition A Bézier curve B (of degree n, with control points \beta_0, \ldots, \beta_n) can be written in Bernstein form as follows :B(t) = \sum_^\beta_b_(t), where b is a Bernstein basis polynomial :b_(t) = (1-t)^t^i. The curve at point t_0 can be evaluated with the recurrence relation :\beta_i^ := \beta_i,\ \ i=0,\ldots,n :\beta_i^ := \beta_i^ (1-t_0) + \beta_^ t_0,\ \ i = 0,\ldots,n-j,\ \ j= 1,\ldots,n Then, the evaluation of B at point t_0 can be evaluated in \binom operations. The result B(t_0) is given by :B(t_0) = \ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics with the major subdisciplines of number theory, algebra, geometry, and analysis, respectively. There is no general consensus among mathematicians about a common definition for their academic discipline. Most mathematical activity involves the discovery of properties of abstract objects and the use of pure reason to prove them. These objects consist of either abstractions from nature orin modern mathematicsentities that are stipulated to have certain properties, called axioms. A ''proof'' consists of a succession of applications of deductive rules to already established results. These results include previously proved theorems, axioms, andin case of abstraction from naturesome basic properties that are considered true starting points of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bézier 2 Big
Bézier can refer to: *Pierre Bézier, French engineer and creator of Bézier curves * Bézier curve * Bézier triangle * Bézier spline (other) *Bézier surface * The town of Béziers in France * AS Béziers Hérault Association Sportive Béziers Hérault ( oc, Associacion Esportiva de Besièrs Erau), often referred to by rugby media simply by its location of Béziers, is a French rugby union club currently playing in the second level of the country's profes ..., a French rugby union team * Bézier Games, an American board game publisher {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Splines (mathematics)
Spline may refer to: Mathematics * Spline (mathematics), a mathematical function used for interpolation or smoothing * Smoothing spline, a method of smoothing using a spline function Devices * Spline (mechanical), a mating feature for rotating elements * Flat spline, a device to draw curves * Spline drive, a type of screw drive * Spline cord, a type of thin rubber cord used to secure a window screen to its frame * Spline (or star filler A star filler (also known as cross filler, splines, separators and crossweb fillers) is a type of plastic insert in Cat 5 and Cat 6 cable which separates the individual stranded pair sets from each other while inside of the cable. It increases the ...), a type of plastic cable filler for CAT cable Other * Spline (alien beings), in Stephen Baxter's Xeelee Sequence novels See also * {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dianne Hansford
Dianne Carol Hansford (born 1964) is an American computer scientist known for her research on Coons patches in computer graphics and for her textbooks on computer-aided geometric design, linear algebra, and the mathematics behind scientific visualization. She is a lecturer at Arizona State University in the School of Computing and Augmented Intelligence, and the cofounder of a startup based on her research, 3D Compression Technologies. Education and career Hansford is a 1986 graduate of the University of Utah The University of Utah (U of U, UofU, or simply The U) is a public research university in Salt Lake City, Utah. It is the flagship institution of the Utah System of Higher Education. The university was established in 1850 as the University of De .... She went to Arizona State University for graduate study, earning a master's degree in 1988 and completing her Ph.D. in 1991. Her dissertation, ''Boundary Curves with Quadric Precision for a Tangent, Continuous Scattered Da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chebyshev Form
The Chebyshev polynomials are two sequences of polynomials related to the trigonometric functions, cosine and sine functions, notated as T_n(x) and U_n(x). They can be defined in several equivalent ways, one of which starts with trigonometric functions: The Chebyshev polynomials of the first kind T_n are defined by : T_n(\cos \theta) = \cos(n\theta). Similarly, the Chebyshev polynomials of the second kind U_n are defined by : U_n(\cos \theta) \sin \theta = \sin\big((n + 1)\theta\big). That these expressions define polynomials in \cos\theta may not be obvious at first sight, but follows by rewriting \cos(n\theta) and \sin\big((n+1)\theta\big) using de Moivre's formula or by using the List of trigonometric identities#Angle sum and difference identities, angle sum formulas for \cos and \sin repeatedly. For example, the List of trigonometric identities#Double-angle formulae, double angle formulas, which follow directly from the angle sum formulas, may be used to obtain T_2(\cos\t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clenshaw Algorithm
In numerical analysis, the Clenshaw algorithm, also called Clenshaw summation, is a recursive method to evaluate a linear combination of Chebyshev polynomials. Note that this paper is written in terms of the ''Shifted'' Chebyshev polynomials of the first kind T^*_n(x) = T_n(2x-1). The method was published by Charles William Clenshaw in 1955. It is a generalization of Horner's method for evaluating a linear combination of monomials. It generalizes to more than just Chebyshev polynomials; it applies to any class of functions that can be defined by a three-term recurrence relation. Clenshaw algorithm In full generality, the Clenshaw algorithm computes the weighted sum of a finite series of functions \phi_k(x): :S(x) = \sum_^n a_k \phi_k(x) where \phi_k,\; k=0, 1, \ldots is a sequence of functions that satisfy the linear recurrence relation :\phi_(x) = \alpha_k(x)\,\phi_k(x) + \beta_k(x)\,\phi_(x), where the coefficients \alpha_k(x) and \beta_k(x) are known in advance. The algor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monomial Form
In mathematics the monomial basis of a polynomial ring is its basis (as a vector space or free module over the field or ring of coefficients) that consists of all monomials. The monomials form a basis because every polynomial may be uniquely written as a finite linear combination of monomials (this is an immediate consequence of the definition of a polynomial). One indeterminate The polynomial ring of univariate polynomials over a field is a -vector space, which has 1, x, x^2, x^3, \ldots as an (infinite) basis. More generally, if is a ring then is a free module which has the same basis. The polynomials of degree at most form also a vector space (or a free module in the case of a ring of coefficients), which has 1, x, x^2, \ldots as a basis. The canonical form of a polynomial is its expression on this basis: a_0 + a_1 x + a_2 x^2 + \dots + a_d x^d, or, using the shorter sigma notation: \sum_^d a_ix^i. The monomial basis is naturally totally ordered, either by increasing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horner Scheme
In mathematics and computer science, Horner's method (or Horner's scheme) is an algorithm for polynomial evaluation. Although named after William George Horner, this method is much older, as it has been attributed to Joseph-Louis Lagrange by Horner himself, and can be traced back many hundreds of years to Chinese and Persian mathematicians. After the introduction of computers, this algorithm became fundamental for computing efficiently with polynomials. The algorithm is based on Horner's rule: :\begin a_0 &+ a_1x + a_2x^2 + a_3x^3 + \cdots + a_nx^n \\ &= a_0 + x \bigg(a_1 + x \Big(a_2 + x \big(a_3 + \cdots + x(a_ + x \, a_n) \cdots \big) \Big) \bigg). \end This allows the evaluation of a polynomial of degree with only n multiplications and n additions. This is optimal, since there are polynomials of degree that cannot be evaluated with fewer arithmetic operations. Alternatively, Horner's method also refers to a method for approximating the roots of polynomials, described by Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Boor's Algorithm
In the mathematical subfield of numerical analysis de Boor's algorithmC. de Boor 971 "Subroutine package for calculating with B-splines", Techn.Rep. LA-4728-MS, Los Alamos Sci.Lab, Los Alamos NM; p. 109, 121. is a polynomial-time and numerically stable algorithm for evaluating spline curves in B-spline form. It is a generalization of de Casteljau's algorithm for Bézier curves. The algorithm was devised by Carl R. de Boor. Simplified, potentially faster variants of the de Boor algorithm have been created but they suffer from comparatively lower stability. Introduction A general introduction to B-splines is given in the main article. Here we discuss de Boor's algorithm, an efficient and numerically stable scheme to evaluate a spline curve \mathbf(x) at position x . The curve is built from a sum of B-spline functions B_(x) multiplied with potentially vector-valued constants \mathbf_i , called control points, : \mathbf(x) = \sum_i \mathbf_i B_(x). B-splines of order p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Projective Space
In mathematics, the concept of a projective space originated from the visual effect of perspective, where parallel lines seem to meet ''at infinity''. A projective space may thus be viewed as the extension of a Euclidean space, or, more generally, an affine space with points at infinity, in such a way that there is one point at infinity of each direction of parallel lines. This definition of a projective space has the disadvantage of not being isotropic, having two different sorts of points, which must be considered separately in proofs. Therefore, other definitions are generally preferred. There are two classes of definitions. In synthetic geometry, ''point'' and ''line'' are primitive entities that are related by the incidence relation "a point is on a line" or "a line passes through a point", which is subject to the axioms of projective geometry. For some such set of axioms, the projective spaces that are defined have been shown to be equivalent to those resulting from the fol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perspective Divide
In linear algebra, linear transformations can be represented by matrices. If T is a linear transformation mapping \mathbb^n to \mathbb^m and \mathbf x is a column vector with n entries, then T( \mathbf x ) = A \mathbf x for some m \times n matrix A, called the transformation matrix of T. Note that A has m rows and n columns, whereas the transformation T is from \mathbb^n to \mathbb^m. There are alternative expressions of transformation matrices involving row vectors that are preferred by some authors. Uses Matrices allow arbitrary linear transformations to be displayed in a consistent format, suitable for computation. This also allows transformations to be composed easily (by multiplying their matrices). Linear transformations are not the only ones that can be represented by matrices. Some transformations that are non-linear on an n-dimensional Euclidean space R''n'' can be represented as linear transformations on the ''n''+1-dimensional space R''n''+1. These include both aff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
