procedures.md

Basic procedures:

Procedure read

Read graph from input file from specified format. This procedure can reuse output file of write procedure written in json format along with graph properties.

required configurations:

• file
• graph-format
  • options: g6, s6, ba, json
  • default: g6

optional configurations:

• number-of-graphs
  • default is all graphs from input file

Example

procedures:
  ...
  - proc-type: read
    config:
      file: graphs.g6
      graph-format: g6 # options: g6, s6, ba, json; default: g6
      # optional
      number-of-graphs: 10 # if not set, take all
  ...

Procedure write

Write graphs to output file in specified format. When set with-properties parameter to true output file will be in JSON format containing graph in specified format and along with it all its properties computed by snark-tool or given in input file. Output file of this procedure in JSON format can be reused by read procedure as input file.

optional configurations:

• file
  • default is 'output'
• graph-format
  • options: g6, s6, ba
  • default is same as input
• with-properties
  • options: true/false
  • option true available only for G6 and S6 graph formats

Example

procedures:
  ...
  - proc-type: write
    config:
      file: output.json
      graph-format: s6
      # if set to true, file format will be json for
      # g6/s6 graph format
      with-properties: true # default true
  ...

Procedure colour

On each graph of currently processed graphs tries to find regular 3-edge colouring using specified algorithm. Foreach graph this procedure adds property colourable: true/false to properties.

required configurations:

• colouriser-type
  • options: dfs, sat, cvd, cvd-dfs, cvd-sat, matching
  • defalt: dfs

Example

procedures:
  ...
  - proc-type: colour
    config:
      # options: dfs, sat, cvd, cvd-dfs, cvd-sat,
      # matching; default: dfs
      colouriser-type: dfs
  ...

Procedure filter

Retains only graphs with properties matched by given filter properties.

required configurations:

• filter-by
  • should contain list of graph properties and its values

Example

procedures:
  ...
  - proc-type: filter
    config:
      filter-by:
        costable: true
        oddness: 2
        edge-resistibility-index:
          comparator: ">" # options: >, <, =, !=, >=, <=
          value: 0
  ...

Procedure chromatic-properties

This procedure resolves specified chromatic properties of given graphs. User can choose only one or all of supported properties listed below.
Snark-tool can resolve these properties sequentially of in parallel by one of supported ways. Currently supported parallel algorithms are:

• graph-based -> uses multiple threads per each given graph
• batch-based -> uses one thread foreach batch of graphs (e.g. 1 thread for 10 graphs)

required configurations:

• properties
  • list of properties to resolve

optional configurations:

• parallelization
  • options: graph-based, batch-based, none
  • default is none
• max-threads
  • e.g. 8
• colouriser-type
  • options: dfs, sat, cvd, cvd-dfs, cvd-sat
  • defalt: dfs

Example

procedures:
  ...
  - proc-type: chromatic-properties
    config:
      # options: graph-based, batch-based, none
      # default: none
      parallelization: graph-based
      # default - number of cpus available
      max-threads: 8
      # options: dfs, sat, cvd-dfs, cvd-sat; default: dfs
      colouriser-type: dfs
      properties:
        - critical
        - cocritical
        - vertex-subcritical
        - edge-subcritical
        - acritical
        - stable
        - costable
        - resistance
        - oddness
        - girth
        - cyclic-edge-connectivity
        - edge-resistibility # for all edges
        - vertex-resistibility # for all vertices
  ...