Isometries and Equivalences Between Point Configurations, Extended To ε\varepsilon-diffeomorphisms

In this paper, we deal with the Orthogonal Procrustes Problem, in which two point configurations are compared in order to construct a map to optimally align the two sets. This extends this to $\varepsilon$-diffeomorphisms, introduced by [1] Damelin and Fefferman. Examples will be given for when complete maps can not be constructed, for if the distributions do match, and finally an algorithm for partitioning the configurations into polygons for convenient construction of the maps.Comment: version: 11.26.1

An Algebraic-Coding Equivalence to the Maximum Distance Separable Conjecture

We formulate an Algebraic-Coding Equivalence to the Maximum Distance Separable Conjecture. Specifically, we present novel proofs of the following equivalent statements. Let $(q,k)$ be a fixed pair of integers satisfying $q$ is a prime power and $2\leq k \leq q$. We denote by $\mathcal{P}_q$ the vector space of functions from a finite field $\mathbb{F}_q$ to itself, which can be represented as the space $\mathcal{P}_q := \mathbb{F}_q[x]/(x^q-x)$ of polynomial functions. We denote by $\mathcal{O}_n \subset \mathcal{P}_q$ the set of polynomials that are either the zero polynomial, or have at most $n$ distinct roots in $\mathbb{F}_q$. Given two subspaces $Y,Z$ of $\mathcal{P}_q$, we denote by $\langle Y,Z \rangle$ their span. We prove that the following are equivalent. [A] Suppose that either: 1. $q$ is odd 2. $q$ is even and $k \not\in \{3, q-1\}$. Then there do not exist distinct subspaces $Y$ and $Z$ of $\mathcal{P}_q$ such that: 3. $dim(\langle Y, Z \rangle) = k$ 4. $dim(Y) = dim(Z) = k-1$. 5. $\langle Y, Z \rangle \subset \mathcal{O}_{k-1}$ 6. $Y, Z \subset \mathcal{O}_{k-2}$ 7. $Y\cap Z \subset \mathcal{O}_{k-3}$. [B] Suppose $q$ is odd, or, if $q$ is even, $k \not\in \{3, q-1\}$. There is no integer $s$ with $q \geq s > k$ such that the Reed-Solomon code $\mathcal{R}$ over $\mathbb{F}_q$ of dimension $s$ can have $s-k+2$ columns $\mathcal{B} = \{b_1,\ldots,b_{s-k+2}\}$ added to it, such that: 8. Any $s \times s$ submatrix of $\mathcal{R} \cup \mathcal{B}$ containing the first $s-k$ columns of $\mathcal{B}$ is independent. 9. $\mathcal{B} \cup \{[0,0,\ldots,0,1]\}$ is independent. [C] The MDS conjecture is true for the given $(q,k)$.Comment: This is version: 5.6.18. arXiv admin note: substantial text overlap with arXiv:1611.0235

On best uniform approximation of finite sets by linear combinations of real valued functions using linear programming

We study the best approximation problem: $$\displaystyle \min_{\alpha\in \mathbb R^m}\max_{1\leq i\leq n}\left|y_i -\sum_{j=1}^m \alpha_j \Gamma_j ({\bf x}_i) \right|.$$ Here: $\Gamma:=\left\{\Gamma_1,...,\Gamma_m\right\}$ is a list of functions where for each $1\leq j\leq m$, $\Gamma_j:\Delta \rightarrow \mathbb R$ with $\Delta$ a set of evaluation points $\left\{{\bf x_1},...,{\bf x_n}\right\}$. $\left\{y_1,...,y_n\right\}$ is a set of real values and $\mathbb R^m:=\left\{(\alpha_1,...,\alpha_m),\, \alpha_j\in \mathbb R,\, 1\leq j\leq m\right\}$