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Re: Problem loading OWL ontology with RDF.rb

From: Franco Rondini <rondinif@yahoo.it>
Date: Tue, 9 Aug 2011 20:49:18 +0200
Cc: Gregg Kellogg <gregg@kellogg-assoc.com>, Marcel Otto <marcelotto@gmx.de>
Message-Id: <459220AF-1C19-40C9-AC53-21F62ADD8BC4@yahoo.it>
To: public-rdf-ruby@w3.org
excuse me if the problem may seem trivial but I'm still not able to load a Graph from a owl file directly stored on the local filesystem. Can you help me to point the right direction?

### attempt N.1
	from /Users/ronda/.rvm/rubies/ruby-1.9.2-p290/bin/irb:16:in `<main>'
ruby-1.9.2-p290 :038 > uri = RDF::URI.new(:scheme => 'file', :path => 'owl.owl', :host => '/Users/ronda/Downloads')
 => #<RDF::URI:0x80fc6004(file:///Users/ronda/Downloads/owl.owl)> 
ruby-1.9.2-p290 :039 > g2 = RDF::Graph.load( uri )
Errno::ENOENT: No such file or directory - file:///Users/ronda/Downloads/owl.owl

### attempt N.2
ruby-1.9.2-p290 :029 > g3 = RDF::Graph.load("/Users/ronda/Downloads/owl.owl")
Ronda filename:/Users/ronda/Downloads/owl.owlRDF::FormatError: unknown RDF format: {:base_uri=>#<RDF::URI:0x82c96ae4(/Users/ronda/Downloads/owl.owl)>, :file_name=>"/Users/ronda/Downloads/owl.owl"}

orks fine from http 
ruby-1.9.2-p290 :004 > g = RDF::Graph.load( RDF::OWL )
 => #<RDF::Graph:0x81469084(http://www.w3.org/2002/07/owl#)> 
ruby-1.9.2-p290 :005 > g.count  # => 450

the file used for the tests is obtaineid this way:
[ 02:55:46 ] > cd ~/Downloads/
[ ronda@MacBook-di-Franco-Rondini.local ~/Downloads ]
[ 08:37:31 ] > wget http://www.w3.org/2002/07/owl
--2011-08-09 20:37:49--  http://www.w3.org/2002/07/owl
Resolving www.w3.org... 128.30.52.37
Connecting to www.w3.org|128.30.52.37|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 31861 (31K) [application/rdf+xml]
Saving to: `owl.1'

100%[==================================================================================================================>] 31,861      45.7K/s   in 0.7s    

2011-08-09 20:37:51 (45.7 KB/s) - `owl.1' saved [31861/31861]

[ ronda@MacBook-di-Franco-Rondini.local ~/Downloads ]
[ 08:38:31 ] > mv owl.1 owl.owl
[ ronda@MacBook-di-Franco-Rondini.local ~/Downloads ]
[ 08:38:47 ] > less owl.owl
in the editor it looks good to me. 
thanks and greetings
Franco 

Il giorno 08/ago/2011, alle ore 22.45, Marcel Otto ha scritto:

> Works fine now. Also the dump seems ok to me.
> 
> Thank you very much for the rapid fix
> Marcel
> 
> Am 08.08.2011 22:01, schrieb Gregg Kellogg:
>> 
>> A simple matter of RTFM, to get Nokogiri to decode entities.
>> 
>> Updated gem to version 0.3.4, update with "(sudo) gem update rdf-rdfxml" you should now see the following:
>> 
>> require 'linked data'
>> g = RDF::Graph.load( RDF::OWL )
>> g.count  # => 450
>> 
>> Also, try the following:
>> 
>> g.dump(:ttl, :standard_prefixes => true)
>> 
>> Gregg
>> 
>> 
>> On Aug 8, 2011, at 10:14 AM, Marcel Otto wrote:
>> 
>>> g = RDF::Graph.load( RDF::OWL )
>> 
> 
Received on Thursday, 11 August 2011 22:39:41 GMT

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