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3 votes
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Could SVD be used to optimize the partial inner-products?

Suppose a set $N$ of $n$ distinct points in $m-$dimensional space is given in $X\in\mathbb{R}^{n\times m}$. Also, suppose a subset $L\subset N$, $|L|=l<m<n$, with $m-$dimensional coordinates in ...
usero's user avatar
  • 131
1 vote
0 answers
74 views

How to minimize n-polytope's bounding box with linear transformation?

I am working on an exact algorithm for integer linear programming for my master's thesis: $Ax\leq b, x \in \mathbb{Z}^n$ $cx\rightarrow min$ For my idea to work out, I need a guarantee that n-...
Иван Шумилов's user avatar
1 vote
0 answers
628 views

Totally unimodular Matrices

A matrix is totally uni-modular if the determinant of any (square) sub-matrix is {+1, 0, -1}. My question is, "Is there a way to transform(linear or non) a general matrix into a totally uni-modular ...
Clark's user avatar
  • 11
1 vote
0 answers
1k views

Covariance matrix formula interpretation - what am I missing?

I'm reading a paper that outlines the calculation of a covariance matrix like the following: $C=\displaystyle\sum^{N_b}_{i=1}\vec{x}_i\vec{x}_i^T$ What is the order of this matrix? My interpretation ...
fbrereto's user avatar
  • 111
0 votes
0 answers
108 views

Solutions to matrix equations in the non-negative integers

For an integer matrix $S$, and an integer vector $y$, I'm looking for solutions to $xS = y$ where the entries in $x$ are in the non-negative integers. I've been doing this with Sage's mixed integer ...
JonHales's user avatar
  • 101