Results 271 to 280 of about 167,710 (314)

On rational parametric curve approximation

Computer Aided Geometric Design, 1993
A new method is proposed for the rational approximation of functions. The autors describe extensions to the basic method which permit the generation of approximations satisfying point constraints and derivative constraints of arbitrary order at the endpoints of the interval of interest.
Michael J. Pratt, Ray J. Goult, L. Ye
openaire   +2 more sources

Blending two parametric curves

Computer-Aided Design, 2009
Segments of two given curves can be blended to produce a segment of a new curve. Blending can provide a smooth transition from one curve to another and can give various degrees of smoothness at the endpoints of the blend, where the smoothness is measured analogously to parametric continuity C^(^n^) and geometric continuity G^(^n^). Blending can provide
Dereck S. Meek, Desmond J. Walton
openaire   +1 more source

Parametrization of curves in characteristic \(p\)

Commentarii mathematici Universitatis Sancti Pauli = Rikkyo Daigaku sugaku zasshi, 2004
Let \(K\) be an algebraically closed field of characteristic \(p\), complete for an ultrametric absolute value. It is shown that many algebraic curves over \(K\) admit no parametrization by unbounded meromorphic functions inside an open disc. For example, theorem 3.1 shows that there are no such functions \(f,g\) satifying \(f^m + g^n = 1\) provided ...
A., Boutabaa, A., Escassut
openaire   +2 more sources

Finding parametric curves in an image

1992
We present a reliable and efficient method for extracting simple geometric structures, i.e., straight lines, parabolas, and ellipses, from edge images. The reliability of the recovery procedure which builds the parametric models is ensured by an iterative procedure through simultaneous data classification and parameter estimation.
Ales Leonardis, Ruzena Bajcsy
openaire   +1 more source

Modular Parametrizations of Elliptic Curves

Canadian Mathematical Bulletin, 1985
AbstractMany — conjecturally all — elliptic curves E/ have a "modular parametrization," i.e. for some N there is a map φ from the modular curve X0(N) to E such that the pull-back of a holomorphic differential on E is a modular form (newform) f of weight 2 and level N.
openaire   +2 more sources

On the singularity of a class of parametric curves

Computer Aided Geometric Design, 2006
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
openaire   +2 more sources

Reconsidering algorithms for real parametric curves

Applicable Algebra in Engineering, Communication and Computing, 1995
The authors study the applicability of known algorithms for computing complex parametrizations of curves to the case of real parametrizations. Several results hold over a real curve and its complexification. For example, a real curve has a real parametrization if and only if it has genus zero.
Cesar Alonso, Jaime Gutierrez 0001, Tomás Recio   +2 more
openaire   +1 more source

Parametric cubics as algebraic curves

Computer Aided Geometric Design, 1988
Planar parametric cubics are used to model curves, both by themselves, and as segments of splines. This paper provides first a background in the algebraic curve theory of cubics; specifically, double points, inflection points, tangent lines, standard curves, and slope parametrizations are discussed.
openaire   +2 more sources

Regular curves and proper parametrizations

Proceedings of the international symposium on Symbolic and algebraic computation, 1990
We present an algorithm for determining whether a given rational parametric curve, defined as vector valued function over a finite domain, has a regular parametrization. A curve has a regular parametrization if it has no cusps in its defining interval.
openaire   +1 more source

Improperly parametrized rational curves

Computer Aided Geometric Design, 1986
Improperly parametrized curves, expressed in a parametric representation, are those which do not have a one-to-one correspondence between values of the parameter and points on the curve. The purpose of this paper is to present an algorithm for detecting whether a curve expressed parametrically in terms of rational functions is improperly parametrized ...
openaire   +2 more sources