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DIMACS—Wolfram Documentation

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DIMACS (.col, .col.b)

Background & Context

    • DIMACS graph data format.
    • Commonly used exchange format for graphs.
    • Stores a single undirected graph.
    • Plain text or binary format.
    • DIMACS is an acronym derived from Discrete Mathematics and Theoretical Computer Science.
    • Developed in 1993 at Rutgers University.

Import & Export

  • Import["file.col"] gives a Graph object representing the graph stored in the specified file.
  • Export["file.col",expr] exports an adjacency matrix or edge information representing a graph to the DIMACS format.
  • Import["file.col"] imports the graph from file and returns it as a Graph.
  • Import["file.col",elem] imports the specified element from a DIMACS file.
  • Import["file.col",{{elem1,elem2,…}}] imports multiple elements.
  • The import format can be specified with Import["file","DIMACS"] or Import["file",{"DIMACS",elem,…}].
  • Export["file.col",expr,elem] creates a DIMACS file by treating expr as specifying element elem.
  • Export["file.col",{expr1,expr2,…},{{elem1,elem2,…}}] treats each expri as specifying the corresponding elemi.
  • Export["file.col",expr,opt1->val1,…] exports expr with the specified option elements taken to have the specified values.
  • Export["file.col",{elem1->expr1,elem2->expr2,…},"Rules"] uses rules to specify the elements to be exported.
  • See the following reference pages for full general information:
  • Import, Exportimport from or export to a file
    CloudImport, CloudExportimport from or export to a cloud object
    ImportString, ExportStringimport from or export to a string
    ImportByteArray, ExportByteArrayimport from or export to a byte array

Import Elements

  • General Import elements:
  • "Elements" list of elements and options available in this file
    "Summary"summary of the file
    "Rules"list of rules for all available elements
  • Data representation elements:
  • "AdjacencyMatrix"edge information, given as a matrix
    "EdgeRules"connectivity data for the graph, given as a list of rules
    "Graph"graph stored in the file, given as a Graph object
    "Graphics"graph stored in the file, rendered as a graph plot
    "VertexCount"number of vertices in the graph
  • Import by default uses the "Graph" element when importing from DIMACS.

Options

Examples

Basic Examples  (7)

Import a Graph object from a DIMACS file:

Wolfram Language code: Import["ExampleData/sample.col"]

Import edge rules:

Wolfram Language code: Import["ExampleData/sample.col", "EdgeRules"]

Import the adjacency matrix:

Wolfram Language code: Import["ExampleData/sample.col", "AdjacencyMatrix"] // MatrixForm

Get a list of all available Import elements:

Wolfram Language code: Import["ExampleData/sample.col", "Elements"]

Export a Graph to a DIMACS file:

Wolfram Language code: Export["complete.col", CompleteGraph[5]]

Export an adjacency matrix to the DIMACS format:

Wolfram Language code: ExportString[{{0, 1, 1, 1}, {1, 0, 1, 1}, {1, 1, 0, 1}, {1, 1, 1, 0}}, "DIMACS"]

Export edge rules to a binary DIMACS file:

Wolfram Language code: Export["clique.col.b", {1 -> 2, 1 -> 3, 1 -> 4, 2 -> 3, 2 -> 4, 3 -> 4}]