Visualizing Planar and Space Implicit Real Algebraic Curves with Singularities

We present a new method for visualizing implicit real algebraic curves inside a bounding box in the $2$-D or $3$-D ambient space based on numerical continuation and critical point methods. The underlying techniques work also for tracing space curve in higher-dimensional space. Since the topology of a curve near a singular point of it is not numerically stable, we trace only the curve outside neighborhoods of singular points and replace each neighborhood simply by a point, which produces a polygonal approximation that is $\epsilon$-close to the curve. Such an approximation is more stable for defining the numerical connectedness of the complement of the projection of the curve in $\mathbb{R}^2$, which is important for applications such as solving bi-parametric polynomial systems. The algorithm starts by computing three types of key points of the curve, namely the intersection of the curve with small spheres centered at singular points, regular critical points of every connected components of the curve, as well as intersection points of the curve with the given bounding box. It then traces the curve starting with and in the order of the above three types of points. This basic scheme is further enhanced by several optimizations, such as grouping singular points in natural clusters, tracing the curve by a try-and-resume strategy and handling "pseudo singular points". The effectiveness of the algorithm is illustrated by numerous examples. This manuscript extends our preliminary results that appeared in CASC 2018

Computer Algebra in Scientific Computing [electronic resource] : 20th International Workshop, CASC 2018, Lille, France, September 17–21, 2018, Proceedings /

Chapter “Positive Solutions of Systems of Signed Parametric Polynomial Inequalities” is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.Proof-of-Work Certificates that Can Be Efficiently Computed in the Cloud (Invited Talk) -- On Unimodular Matrices of Difference Operators -- Sparse Polynomial Arithmetic with the BPAS Library -- Computation of Pommaret Bases Using Syzygies -- A Strongly Consistent Finite Difference Scheme for Steady Stokes Flow and its Modified Equations -- Symbolic-Numeric Methods for Nonlinear Integro-Differential Modeling -- A Continuation Method for Visualizing Planar Real Algebraic Curves with Singularities -- From Exponential Analysis to Padé Approximation and Tensor Decomposition, in One and More Dimensions -- Symbolic Algorithm for Generating the Orthonormal Bargmann-Moshinsky Basis for SU(3) Group -- About Some Drinfel'd Associators -- On a Polytime Factorization Algorithm for Multilinear Polynomials over F2 -- Tropical Newton-Puiseux Polynomials -- Orthogonal Tropical Linear Prevarieties -- Symbolic-Numerical Algorithms for Solving Elliptic Boundary-Value Problems Using Multivariate Simplex Lagrange Elements -- Symbolic-Numeric Simulation of Satellite Dynamics with Aerodynamic Attitude Control System -- Finding Multiple Solutions in Nonlinear Integer Programming with Algebraic Test-Sets -- Positive Solutions of Systems of Signed Parametric Polynomial Inequalities -- Qualitative Analysis of a Dynamical System with Irrational First Integrals -- Effective Localization Using Double Ideal Quotient and Its Implementation -- A Purely Functional Computer Algebra System Embedded in Haskell -- Splitting Permutation Representations of Finite Groups by Polynomial Algebra Methods -- Factoring Multivariate Polynomials with Many Factors and Huge Coefficients -- Beyond the First Class of Analytic Complexity -- A Theory and an Algorithm for Computing Sparse Multivariate Polynomial Remainder Sequence -- A Blackbox Polynomial System Solver on Parallel Shared Memory Computers.Chapter “Positive Solutions of Systems of Signed Parametric Polynomial Inequalities” is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com