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Effects of the numerical values of the parameters in the Gielis equation on its geometries

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posted on 2023-05-21, 15:03 authored by Wang, L, David RatkowskyDavid Ratkowsky, Gielis, J, Ricci, PE, Shi, P
The Lame curve is an extension of an ellipse, the latter being a special case. Dr. Johan Gielis further extended the Lame curve in the polar coordinate system by introducing additional parameters (n1, n2, n3; m): r(o)=(||1Acos(m4o)||n2+||1Bsin(m4o)||n3)-1/n1, which can be applied to model natural geometries. Here, r is the polar radius corresponding to the polar angle o; A, B, n1, n2 and n3 are parameters to be estimated; m is the positive real number that determines the number of angles of the Gielis curve. Most prior studies on the Gielis equation focused mainly on its applications. However, the Gielis equation can also generate a large number of shapes that are rotationally symmetric and axisymmetric when A = B and n2 = n3, interrelated with the parameter m, with the parameters n1 and n2 determining the shapes of the curves. In this paper, we prove the relationship between m and the rotational symmetry and axial symmetry of the Gielis curve from a theoretical point of view with the condition A = B, n2 = n3. We also set n1 and n2 to take negative real numbers rather than only taking positive real numbers, then classify the curves based on extremal properties of r(o) at o = 0, PI/m when n1 and n2 are in different intervals, and analyze how n1, n2 precisely affect the shapes of Gielis curves.

History

Publication title

Symmetry

Volume

14

Issue

12

Article number

2475

Number

2475

Pagination

1-12

ISSN

2073-8994

Department/School

Tasmanian Institute of Agriculture (TIA)

Publisher

MDPI AG

Place of publication

Switzerland

Rights statement

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY 4.0) license (https://creativecommons.org/licenses/by/4.0/).

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  • Open

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Expanding knowledge in the mathematical sciences

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