RT info:eu-repo/semantics/article T1 On the Shape of Curves that are Rational in Polar Coordinates A1 Alcázar Arribas, Juan Gerardo A1 Díaz Toca, Gema Maria K1 Polar coordinates K1 Planar curve K1 Spiral K1 Rational curve K1 Ciencia K1 Matemáticas K1 Science K1 Mathematics AB In this paper we provide a computational approach to the shapeof curves which are rational in polar coordinates. Our study includes theoretical aspects on the shape of these curves, and algorithmic results which eventually lead to an algorithm for plotting the ``interesting parts" of the curve, i.e. the parts showing the main geometrical features of it. On the theoretical side, we prove that these curves, with the exceptions of lines and circles, cannot be algebraic (in cartesian coordinates), we characterize the existence of infinitely many self-intersections, and we connect this with certain phenomena which are not possible in the algebraic world, namely the existence of limit circles, limit points, or spiral branches. On the practical side, we provide an algorithm which has been implemented in the computer algebra system Maple to visualize this kind of curves.Our implementation makes use (and improves some aspects of) the command "polarplot" currently available in Maple for plotting curves in polar form. PB Elsevier SN 0167-8396 YR 2012 FD 2012 LK http://hdl.handle.net/10017/20444 UL http://hdl.handle.net/10017/20444 LA eng NO The final version of this paper was published as AlcázarJ.G., Díaz Toca G.M. (2012), On the Shape of Curves that are Rational in PolarCoordinates, Computer Aided Geometric Design, Vol. 29 Issue 9, pp. 665-675. NO Ministerio de Ciencia e Innovación DS MINDS@UW RD 25-abr-2024