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Bargraphs and Semantics

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  • david_dodds_2001
    Copyright 2008 David Dodds Bargraphs and Semantics As you recall from episode 397 we saw the sea of angle brackets called myfoo_barchart.xml .svg. In that
    Message 1 of 1 , Jun 10, 2008
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      Copyright 2008 David Dodds

      Bargraphs and Semantics

      As you recall from episode 397 we saw the sea of angle brackets called
      myfoo_barchart.xml .svg. In that file was a line '<myfoo:what>widget
      growth bar graph' and in this episode we talk about that.

      '<myfoo:what>' is part of an SVG Description element in that SVG
      program. The 'myfoo' namespace defines a number of elements forming a
      structure which packages a description of the SVG graphics in the file
      which the description is embedded in. Ordinarily an SVG Description
      element content is not output by an SVG displaying program, it sits
      rather inertly in the text of the SVG code acting more or less the way
      a Comment does in other computer languages. The SVG specification says
      that both the Title and the Description element may have a namespace
      used in them. It would be incumbent then upon any processor dealing
      with such an SVG text file that the namespace be read as XML readers
      read any namespace material. The content and 'tags' are placed into
      the DOM (Document Object Model) as constituting part of the overall
      XML (SVG) file. Also remember that (the SVG Title and) the Description
      element may have XML IDs associated with them.

      The '<myfoo:what>' is used to contain information about 'IS what', or
      'IS x', the copula verb in English which is about (named) 'being' or
      named 'exists x' where x is just the name or label assigned (by a
      culture) to the thing or concept that 'IS'. In this case x is 'widget
      growth bar graph'. So there is the suggestion that the SVG 'picture'
      is an instance of 'bargraph thing'. The modifier (adj phrase) 'widget
      growth'can be parsed to provide some nuance information about the
      'bargraph thing'. '<myfoo:what>' is (what(ie, a description) 'is'
      bargraph-'being-ness'.

      We can see that the system 'knows'/has expectancies about what
      evidence to find/look for to confirm 'bar graph-ness' by virtue of
      using the following ontologies:
      The NASA JPL SWEET ontologies, in particular space.owl and numeric.owl
      and also the ontology.dumontierlab.com/statistical-graph-primitive.
      The system knows that using these ontologies may be beneficial to
      "understanding" the SVG file because the system has found 'graph' in
      the '<myfoo:what>' element content, and can use 'graph' to identify
      the semantic domain to search/examine in order to 'make sense' of the
      SVG file content, including the Description element and its scene-graph.

      Using the PCS facility which was described in previous episodes, we
      can cross-tie-into SWEET space.owl and numeric.owl because parts of
      'ontology.dumontierlab' leave some important/ relevant 'knowledge'
      unsaid/not explicit. We discuss this next.

      (Sorry that Yahoo totally trashes rational whitespace in XML code. Ive
      tried a couple of different ways to retain rational spacing and
      indentation but to no avail. See PDF version of this post for decent
      indentation.)

      dumontierlab material below is Copyright dumontierlab.com
      (some of the text below is my text and it is under my Copyright 2008
      David Dodds)


      <!-- http://ontology.dumontierlab.com/Bar -->
      -
      <owl:Class rdf:about="http://ontology.dumontierlab.com/Bar">
      <rdfs:label>bar</rdfs:label>
      <rdfs:subClassOf
      rdf:resource="http://ontology.dumontierlab.com/GeometricObject"/>
      </owl:Class>

      <!-- http://ontology.dumontierlab.com/BarGraph -->
      -
      <owl:Class rdf:about="http://ontology.dumontierlab.com/BarGraph">
      <rdfs:label>bar graph</rdfs:label>
      <rdfs:subClassOf rdf:resource="http://ontology.dumontierlab.com/Graph"/>
      <rdfs:comment>A graph that uses bars to display data.</rdfs:comment>
      </owl:Class>


      <!-- http://ontology.dumontierlab.com/Graph -->
      -
      <owl:Class rdf:about="http://ontology.dumontierlab.com/Graph">
      <rdfs:label>graph</rdfs:label>
      -
      <rdfs:comment>
      An information graphic that displays the relationship among tabular
      numeric data and/or functions.
      </rdfs:comment>
      </owl:Class>


      Well, the system is able to recognize that the text 'bar graph' from
      the '<myfoo:what>' SVG Description element is the same as 'BarGraph'
      in the above Dumontierlab ontology snippet.

      The ontology starts off with some Dublin Core information including
      that the subject is 'graph' and the format of the ontology is OWL/RDF/XML.

      <!-- http://ontology.dumontierlab.com/.. -->

      <owl:Ontology rdf:about="">
      <owl:versionInfo
      rdf:datatype="http://www.w3.org/2001/XMLSchema#string">2.0</owl:versionInfo>
      <dc:subject
      rdf:datatype="http://www.w3.org/2001/XMLSchema#string">graph</dc:subject>
      <dc:format
      rdf:datatype="http://www.w3.org/2001/XMLSchema#string">rdf/xml</dc:format>
      -
      <dc:description>
      An ontology of statistical graphs and their components.
      </dc:description>

      Notice that the Dublin Core 'description' is just a comment, a string
      of text with no references to any ontology or other info-source. The
      text which constitutes the content of the <dc:description> is meant
      for human eyeballs only, it is only there the string of text has any
      meaning. At least the system analyzing the SVG file can use the
      dc:subject (graph) to determine that this particular ontology is
      likely to have valuable (useful) ontological information in it
      regarding the making-sense of the SVG picture. If the the human who
      made the bar graph SVG description had lied and put ferris wheel
      instead of bar chart things would proceed much more slowly. (How such
      things are handled we see in another episode.)

      Ok, so far the system analyzing the SVG file with the SVG Description
      of <myfoo:what>widget growth bar graph has located an ontology
      'ontology.dumontierlab.com' which says it is about 'graphs', and a
      term '. /BarGraph' which the ontology says is a 'subClassOf
      rdf:resource="./Graph"'.
      It (ontology.dumontierlab) goes on to show: '"./Bar">' is a
      '<rdfs:subClassOf' './GeometricObject"/>'.
      But does not provide any qualification or description of the nature of
      'Bar' being a 'subclass of' 'GeometricObject.' Whereas we see that
      there is information precisely about these missing qualifications or
      descriptions in the NASA JPL SWEET ontologies. In a near future
      episode we will continue this thread by showing what the SWEET items
      are and how PCS is used to virtually merge these ontologies into one
      coherent knowledge source about the SVG bar chart file and its contents.

      A final thought for this episode, next (example) we see that the
      ontology.dumontierlab has a provision '"./hasSource"' which associates
      the 'widget growth' (text) part of the bargraph's SVG file, its SVG
      Description in particular, as being the 'source' of info for the
      graph. Widgets (this is stated colloquially, actually it is the
      time-series of the widget values which) are the topic. Here the
      'source' (of numeric data). Ontology.dumontierlab also contains
      knowledge about other components in the SVG picture such as the
      end-lines, the titles, the axis-labels and so on. Next episode we see
      how the SVG bargraph is analyzed further; and, hence, 'made sense of'
      using the ontologies above.

      <!-- http://ontology.dumontierlab.com/hasSource -->
      -
      <owl:ObjectProperty
      rdf:about="http://ontology.dumontierlab.com/hasSource">
      <rdfs:label>has source</rdfs:label>
      <rdfs:range rdf:resource="http://ontology.dumontierlab.com/Source"/>
      <rdfs:domain rdf:resource="http://ontology.dumontierlab.com/Graph"/>
      -
      <rdfs:comment>
      The relation between an entity and its source of origin.
      </rdfs:comment>
      </owl:ObjectProperty>
      Stay tuned for the next thrilling episode of Captain Semantic.
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