Submitter	Variables	Constraints	Density	Status	Group	Objective	MPS File
Sascha Kurz	11811	14478	1.51955e-03	open	–	-260*	cdc7-4-3-2.mps.gz

Codes for Networkcoding A constant dimension code with parameters n, k, d and q is a collection of k-dimensional subspaces of the n-dimensional vector space \(GF(q)^n\) over a finite field with q elements, called codewords, such that the dimension of the intersection of each pair of different k-dimensional subspaces is at most \(k-d/2\). Let \(A_q(n,d;k)\) denote the maximum number of codewords. For instance cdc6-4-3-2 \(A_2(6,4;3)=77\) is known , while \(333 \le A_2(7,4;3) \le 381\) for instance cdc7-4-3-2 are the tightest known bounds, see e.g. . A code of size 381 would correspond to a putative binary q-analog of the Fano plane (finite projective plane of order 2 with 7 points and lines). More bounds are available at http://subspacecodes.uni-bayreuth.de.

Location of instance in collection

Instance Statistics

Detailed explanation of the following tables can be found here.

Size Related Properties
	Original	Presolved
Variables	11811	11811
Constraints	14478	14478
Binaries	11811	11811
Integers	0	0
Continuous	0	0
Implicit Integers	0	0
Fixed Variables	0	0
Nonzero Density	0.00151955	0.00151955
Nonzeroes	259842	259842

Constraint Classification Properties
	Original	Presolved
Total	14478	14478
Empty	0	0
Free	0	0
Singleton	0	0
Aggregations	0	0
Precedence	0	0
Variable Bound	0	0
Set Partitioning	0	0
Set Packing	14478	14478
Set Covering	0	0
Cardinality	0	0
Invariant Knapsack	0	0
Equation Knapsack	0	0
Bin Packing	0	0
Knapsack	0	0
Integer Knapsack	0	0
Mixed Binary	0	0
General Linear	0	0
Indicator	0	0

Structure

Available nonzero structure and decomposition information. Further information can be found here.

Nonzero entries of original problem

Nonzero entries after trivial presolving

Decomposed structure of original problem (dec-file)

Decomposed structure after trivial presolving (dec-file)

	value	min	median	mean	max
Components	0.30103
Constraint %		100	100	100	100
Variable %		100	100	100	100
Score	0.00000

Best Known Solution(s)

Find solutions below. Download the archive containing all solutions from the Download page.

ID	Objective	Exact	Int. Viol	Cons. Viol	Obj. Viol	Submitter	Date	Description
1	-260	-260	0	0	0	-	2018-10-13	Solution found during MIPLIB2017 problem selection.

Similar instances in collection

The following instances are most similar to cdc7-4-3-2 in the collection. This similarity analysis is based on 100 scaled instance features describing properties of the variables, objective function, bounds, constraints, and right hand sides.

Instance	Variables	Binaries	Constraints	Nonz.	Submitter	Group	Status	Objective
cod105	1024	1024	1024	57344	MIPLIB submission pool	–	easy	-12
a2864-99blp	200787	200787	22117	20078700	Daniel Heinlein	selofsubspaces	open	-257*
sorrell8	2046	2046	18944	37888	Toni Sorrell	independentset	open	-350*
sorrell7	2048	2048	78848	157696	Toni Sorrell	independentset	open	-185*
z26	17937	17937	850513	1715610	Daniel Bienstock	–	open	-1101*

Reference

@article{honold2015optimal,
  title={Optimal binary subspace codes of length 6, constant dimension 3 and minimum subspace distance 4},
  author={Honold, Thomas and Kiermaier, Michael and Kurz, Sascha},
  journal={Contemporary Mathematics},
  volume={632},
  pages={157--172},
  year={2015},
}

@incollection{kohnert2008construction,
  title={Construction of large constant dimension codes with a prescribed minimum distance},
  author={Kohnert, Axel and Kurz, Sascha},
  booktitle={Mathematical Methods in Computer Science},
  volume={5393},
  pages={31--42},
  year={2008},
  publisher={Springer}
}

Last Update Jan 18, 2019 by Gregor Hendel
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