On faster convergence of the bisection method for all triangles
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- by Martin Stynes PDF
- Math. Comp. 35 (1980), 1195-1201 Request permission
Abstract:
Let $\Delta ABC$ be a triangle with vertices A, B, and C. It is "bisected" as follows: choose a/the longest side (say AB) of $\Delta ABC$, let D be the midpoint of AB, then replace $\Delta ABC$ by two triangles $\Delta ADC$ and $\Delta DBC$. Let ${\Delta _{01}}$ be a given triangle. Bisect ${\Delta _{01}}$ into two triangles ${\Delta _{11}}$ and ${\Delta _{12}}$. Next bisect each ${\Delta _{1i}},\;i = 1,2$, forming four new triangles ${\Delta _{2i}},\;i = 1,2,3,4$. Continue thus, forming an infinite sequence ${T_j},\;j = 0,1,2, \ldots$, of sets of triangles, where ${T_j} = \left \{ {{\Delta _{ji}}:1 \leqslant i \leqslant {2^j}} \right \}$. Let ${m_j}$ denote the mesh of ${T_j}$. It is shown that there exists $N = N({\Delta _{01}})$ such that, for $j \geqslant N$, ${m_{2j}} \leqslant {(\sqrt 3 /2)^N}{(1/2)^{j - N}}{m_0}$, thus greatly improving the previous best known bound of ${m_{2j}} \leqslant {(\sqrt 3 /2)^j}{m_0}$. It is also shown that only a finite number of distinct shapes occur among the triangles produced, and that, as the method proceeds, ${\Delta _{01}}$ tends to become covered by triangles which are approximately equilateral in a certain sense.References
- Baker Kearfott, A proof of convergence and an error bound for the method of bisection in $\textbf {R}^{n}$, Math. Comp. 32 (1978), no. 144, 1147–1153. MR 494897, DOI 10.1090/S0025-5718-1978-0494897-3
- Ivo G. Rosenberg and Frank Stenger, A lower bound on the angles of triangles constructed by bisecting the longest side, Math. Comp. 29 (1975), 390–395. MR 375068, DOI 10.1090/S0025-5718-1975-0375068-5
- Martin Stynes, On faster convergence of the bisection method for certain triangles, Math. Comp. 33 (1979), no. 146, 717–721. MR 521285, DOI 10.1090/S0025-5718-1979-0521285-4 M. STYNES, "Why Stenger’s topological degree algorithm usually works in ${R^3}$." (In preparation.)
- J. H. C. Whitehead, On $C^1$-complexes, Ann. of Math. (2) 41 (1940), 809–824. MR 2545, DOI 10.2307/1968861
Additional Information
- © Copyright 1980 American Mathematical Society
- Journal: Math. Comp. 35 (1980), 1195-1201
- MSC: Primary 51N99; Secondary 65B99, 65N30
- DOI: https://doi.org/10.1090/S0025-5718-1980-0583497-1
- MathSciNet review: 583497