Java Reference
In-Depth Information
cesses one
Span
object at a time displaying the basic span information. The inner for
loop displays the spanned text enclosed within brackets:
Span[] spans = chunkerME.chunkAsSpans(sentence, tags);
for (Span span : spans) {
System.out.print("Type: " + span.getType() + " - "
+ " Begin: " + span.getStart()
+ " End:" + span.getEnd()
+ " Length: " + span.length() + " [");
for (int j = span.getStart(); j < span.getEnd(); j++) {
System.out.print(sentence[j] + " ");
}
System.out.println("]");
}
The following output clearly shows the span type, its position in the
sentence
array, its
length, and then the actual spanned text:
Type: NP - Begin: 0 End:2 Length: 2 [The voyage ]
Type: PP - Begin: 2 End:3 Length: 1 [of ]
Type: NP - Begin: 3 End:6 Length: 3 [the Abraham Lincoln ]
Type: VP - Begin: 6 End:7 Length: 1 [was ]
Type: PP - Begin: 7 End:8 Length: 1 [for ]
Type: NP - Begin: 8 End:11 Length: 3 [a long time ]
Type: VP - Begin: 11 End:12 Length: 1 [marked ]
Type: PP - Begin: 12 End:13 Length: 1 [by ]
Type: NP - Begin: 13 End:16 Length: 3 [no special
incident. ]
Using the POSDictionary class
A tag dictionary specifies what are the valid tags for a word. This can prevent a tag from
being applied inappropriately to a word. In addition, some search algorithms execute
faster since they do not have to consider other less probable tags.
In this section, we will demonstrate how to:
• Obtain the tag dictionary for a tagger
• Determine what tags a word has
• Show how to change the tags for a word
