[R] Using R to convert RDF/XML to

Evans, Richard K. (GRC-H000) r|ch@rd@k@ev@n@ @end|ng |rom n@@@@gov
Fri Dec 31 15:19:21 CET 2021

Hello R community,

I am a novice R enthusiast trying to use R to convert an RDFdump file [1] from Semantic Mediawiki [2] into something that can be natively imported by GePhi [3] for graph visualization. The SMW RDFdump file is formatted as RDF/XML and I have found the R package "rdflib" [4] and am able to read the RDF/XML file into R as an "rdf" object, but it is not clear to me how to save the "rdf_serialize" function output to a new file. 

What I have so far is: 
NewRDF <- tempfile( "TempFile", fileext = ".nq" )
MyRDF <- rdf_parse( "MyRDFdumpFile.txt" )
rdf_serialize( MyRDF, NewRDF, format = "nquads"  )
write_nquads( MyRDF, NewRDF ) 

..but this results in the error: "Error: object of type 'closure' is not subsettable"

I will keep struggling with this to learn what I need to learn, but any advice to help make quick work of this would be much appreciated. 

Thank you in advance.

[1] https://www.semantic-mediawiki.org/wiki/Help:Maintenance_script_dumpRDF.php
[2] https://www.semantic-mediawiki.org/wiki/Help:Introduction_to_Semantic_MediaWiki
[3] https://gephi.org/
[4] https://cran.r-project.org/web/packages/rdflib/rdflib.pdf

- Richard Evans, NASA GRC - Armstrong Test Facility

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