Difference between revisions of "CYK Parsing"

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<pre>
 
<pre>
for each i = 1 to n
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''for'' each i = 1 to n
   for each production A -> a
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   ''for'' each production A -> a
     if a == X[i]
+
     ''if'' a == X[i]
       Add A to C[i,i]
+
       ''add'' A to C[i,i]
  
  
 
</pre>
 
</pre>

Revision as of 18:45, 30 October 2011

This is a Method page for CYK Parsing.

The Cocke–Younger–Kasami (CYK) algorithm is an algorithm for parsing PCFG. It is bottom up and makes use of dynamic programming.

Description

The input to the algorithm is a grammar in Chomsky Normal Form, and a sentence . The idea behind the parsing algorithm is to recursively build parses from bottom up, and mantaining a chart C[i, j] which contains productions that generates X[i] ... X[j].

Pseudocode

''for'' each i = 1 to n
  ''for'' each production A -> a
    ''if'' a == X[i]
      ''add'' A to C[i,i]