Abstract

Although Cylindrical Algebraic Decomposition (CAD) is widely used to study the topology of semi-algebraic sets (especially algebraic curves), there are very few studies of the topological properties of the output of the CAD algorithms. In this paper three possible bad topological properties of the output of CAD algorithms are described. It is shown that these properties may not occur after a generic change of coordinates and that they may be avoided, in dimension not greater than three, with a modification of the CAD algorithm. As this modification of the CAD algorithm requires to solve some polynomial systems, it is also shown that the computation with real algebraic numbers may be advantageously replaced, in all the variants of the CAD algorithm, by solving systems of polynomial equations and inequalities.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.