view feature-description-example.n3 @ 325:d5caf5e91a86 default-writer-writes-to-files

If the default writer were to be able to write to files (but this is backward-incompatible so probably unwise)

@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix dc: <http://purl.org/dc/elements/1.1/> .
@prefix mo: <http://purl.org/ontology/mo/> .
@prefix af: <http://purl.org/ontology/af/> .
@prefix event: <http://purl.org/NET/c4dm/event.owl#> .
@prefix tl: <http://purl.org/NET/c4dm/timeline.owl#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix : <#> .


# Describe the signal we're annotating, and associate it with a
# timeline (the timeline is named as :base_timeline but never given
# any attributes in this document).  Any feature that is associated
# with the same timeline will be taken as derived from this signal.

:audio_signal a mo:Signal ;
        mo:available_as <file:///path/to/myfile.wav> ;
        mo:time :signal_interval .

:signal_interval a tl:Interval ;
                 tl:onTimeLine :base_timeline ;
                 tl:beginsAt "PT0"^^xsd:duration .


# A sparse feature event.

:event0 a af:Onset ;
        event:time :time0 .

:time0 a tl:Instant ;
       tl:onTimeLine :base_timeline ;
       tl:at "PT0.185759637S"^^xsd:duration .

# Alternatively we could write that with a blank node.

:event1 a af:Onset ;
        event:time [
                   a tl:Instant ;
                   tl:onTimeLine :base_timeline ;
                   tl:at "PT0.510839002S"^^xsd:duration ;
                   ] .


# For a dense feature, we need an appropriately sampled, windowed timeline.

:feature_timeline a tl:DiscreteTimeLine .

:feature_timeline_map a tl:UniformSamplingWindowingMap ;
               tl:rangeTimeLine :feature_timeline ;
               tl:domainTimeLine :base_timeline ;
               tl:sampleRate "44100"^^xsd:int ;
               tl:windowLength "1024"^^xsd:int ;
               tl:hopSize "512"^^xsd:int .


# ... and an interval, defined in terms of hops (the discrete steps of
# the windowed timeline).

:feature_interval a tl:Interval ;
                  tl:onTimeLine :feature_timeline ;
                  tl:beginsAt "0"^^xsd:int ;
                  tl:duration "5634"^^xsd:int .


# Then our feature is a signal that is on the interval we just
# described.  We associate it explicitly with the original audio
# signal, although presumably we could leave the association implicit,
# to be derived from the relationships between timelines, just as it
# is for the sparse features above.

:audio_signal af:signal_feature :feature1 .

:feature_signal_type rdfs:subClassOf af:DetectionFunction ;
          dc:title "Detection Function from Simple Percussion Onset Detector" .

:feature1 a :feature_signal_type ;
          mo:time :feature_interval ;
          af:dimensions "12 12345" ;
          af:value "0 0 0 0 0 0 0 1 2 3 1 24 236 123213 (etc)" .