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General uncrossing covering paths inside the axis-aligned bounding box

Marco Ripà

TL;DR

For any n_k≥3, the link length of the covering path provided by the MΛI-algorithm is smaller than the cardinality of the set G(n_1, n_2,...,n_k).

Abstract

Given the finite set of $n_1 \cdot n_2 \cdot \ldots \cdot n_k$ points $G_{n_1,n_2,\ldots,n_k} \subset \mathbb{R}^k$ such that $n_k \geq \cdots \geq n_2 \geq n_1 \in \mathbb{Z}^+$, we introduce a new algorithm, called M$Λ$I, which returns an uncrossing covering path inside the minimum axis-aligned bounding box $[0,n_1-1] \times [0,n_2-1] \times \cdots \times [0,n_k-1]$, consisting of $3 \cdot \prod_{i=1}^{k-1} n_i-2$ links of prescribed length $n_k-1$ units. Thus, for any $n_k \geq 3$, the link length of the covering path provided by our M$Λ$I-algorithm is smaller than the cardinality of the set $G_{n_1,n_2,\ldots,n_k}$. Furthermore, assuming $k>2$, we present an uncrossing covering path for $G_{3,3,\ldots,3}$, consisting of $20 \cdot 3^{k-3}-2$ straight-line edges that are $2$ units long each, which is constrained by the axis-aligned bounding box $\left[0,4-\sqrt{3}\right] \times \left[0,4-\sqrt{3}\right] \times [0, 2]^{k-2}$.

General uncrossing covering paths inside the axis-aligned bounding box

TL;DR

For any n_k≥3, the link length of the covering path provided by the MΛI-algorithm is smaller than the cardinality of the set G(n_1, n_2,...,n_k).

Abstract

Given the finite set of points such that , we introduce a new algorithm, called MI, which returns an uncrossing covering path inside the minimum axis-aligned bounding box , consisting of links of prescribed length units. Thus, for any , the link length of the covering path provided by our MI-algorithm is smaller than the cardinality of the set . Furthermore, assuming , we present an uncrossing covering path for , consisting of straight-line edges that are units long each, which is constrained by the axis-aligned bounding box .
Paper Structure (3 sections, 12 equations, 9 figures)

This paper contains 3 sections, 12 equations, 9 figures.

Figures (9)

  • Figure 1: First layer of the covering path $P_{3,3,3}$, edges $1$ to $7$: all of them belong to the length class $2$. The two Steiner points (in green) are $S_1 \equiv \left(\frac{1}{2},2-\frac{\sqrt{15}}{2}\right) \cong (0.5, 0.063508)$ and $S_2 \equiv \left(\frac{3}{2},\frac{\sqrt{15}}{2}\right) \cong (1.5, 1.936492)$8.
  • Figure 2: The whole directed covering path $P_{3,3,3}$, edges $1$ to $25$: all of them belong to the length class $2$8.
  • Figure 3: The self-intersecting covering path $M_{3,3}$ consists of $8$ edges, and all of them belong to the length class $\sqrt{5}$8.
  • Figure 4: The covering path $\check{P}_{3,3}=(0,2)$-$(0,0)$-$(2,0)$-$(2,2)$-$(1,2-\sqrt{3})$-$(1,4-\sqrt{3})$8.
  • Figure 5: The (uncrossing) covering path $\check{P}_{3,3,3}=(0,2,0)$-$(0,0,0)$-$(2,0,0)$-$(2,2,0)$-$(1,2-\sqrt{3},0)$-$(1,4-\sqrt{3},0)$-$(1,4-\sqrt{3},2)$-$(1,2-\sqrt{3},2)$- $(2,2,2)$-$(2,0,2)$-$(0,0,2)$-$(0,2,2)$-$\left(\frac{7}{10},\frac{33 \cdot \sqrt{3}-37+\sqrt{2 \cdot \left(2541 \cdot \sqrt{3}-4247 \right)}}{20},\frac{33 \cdot \sqrt{3}-37-\sqrt{2 \cdot \left(2541 \cdot \sqrt{3}-4247 \right)}}{20}\right)$- $(4-\sqrt{3},1,1)$-$(2-\sqrt{3},1,1)$-$(2,0,1)$-$(0,0,1)$-$(0,2,1)$-$(2,2,1)$ extends $\check{P}_{3,3}$ to $3$ dimensions 8.
  • ...and 4 more figures

Theorems & Definitions (6)

  • Definition 1.1
  • Definition 1.2
  • Definition 1.3
  • Definition 1.4
  • Definition 1.5
  • Definition 1.6