More Xkwic and Tgrep

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More Xkwic and Tgrep

• LING 5200
• Computational Corpus Linguistics
• Martha Palmer
• March 2, 2006

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Resources Laura is bugging me to make a CU
Corpora page

• Like this
• http//www.stanford.edu/dept/linguistics/corpora/
  cas-home.html
• TGREP http//www.stanford.edu/dept/linguistics/cor
  pora/cas-tut-tgrep.html

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Searching with pos tags and !

• word "tThe" !( pos "DT" ) wsj
• !(word "water" pos "NN")
• !(word "water") !( pos "NN")
• word ! "water" pos ! "NN"

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Operator precedence

• The precedence properties of the (logical)
  operators are defined by the following list, i.e.
  if operator x is listed before operator y,
  operator x has precedence over y. Operators are
  evaluated left-right
• , !, !, ,
• ! word "water" ! pos "NN"
  disambiguates as
• !(word "water") !( pos "NN")

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Searching sequences with and ?

• "Bill" pos "NP"
• pos "NP" pos "NP" pos "NP"
• (pos "NP" pos "NP")
• (pos "NP" "of" pos "NP")
• (pos "NP" "of? pos "NP")
• Note First match applies

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Corpus Position wild cards and contexts

• "give" "up"
• "give" 0,5 "up"
• "give" "up" within 7
• "Clinton" expand to 5
• "Clinton" expand left to 5
• "Clinton" expand right to 5

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Assignments and Intersect

• Q1 "rain"
• Q2 pos"NN"
• intersect Q1 Q2
• Q1 pos "JJ" pos "NN"
• Q2 "acid" "rain"
• intersect Q1 Q2
• word "acid" pos "JJ" word "rain" pos
  "NN"

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Structural restrictions

• "give" "up" within s
• ("gain" "profit") ("profit" "gain")
  within 3 s
• ("gain" "profit") ("profit" "gain")
  within article
• "Clinton" expand left to 2 s

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Defining structural restrictions

• Nounphrase pos "DT" pos "JJ" pos
  "NN"
• Nounphrase
• pos JJ
• Go back to select

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For fun

• ltsgt pos "V."pos "PN. lt/sgt
• ltsgt pos "V."pos "PN. lt/sgt
• ( pos V. pos PN.) within s
• Not a question, not beginning of sentence

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less is more

• less ltfilenamegt
• cat ??/ less
• Switches
• SPACE next screenful
• b previous screenful
• /ltreg exp patterngt /RNR search for pattern
• ?ltreg exp patterngt search backwards for pattern
• q - quit

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Searching for a word

• tgrep Halloween what happens?
• Why dont you have to specify a file?
• babelgtgrep tgrep .cshrc
• tgrep stuff
• setenv TGREP_CORPUS /corpora/treebank2/tbl_075/tg
  repabl/brwn_cmb.crp
• setenv TGREP_CORPUS /corpora/treebank2/tgrepabl/ws
  j_mrg.crp
• Count results tgrep research wc l
• cat ??/ grep Halloween wc -l

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Tgrep Switches

• -a Match on all patterns in a sentence
• -w Return the whole sentence
• -n Put the entire string on one line
• -t Print only the terminals

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Viewing it in sentential context

• tgrep wn Halloween more
• tgrep wn research more (20,865 hits)
• Can also use less

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Viewing it in sentential context

• tgrep wn research more

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Searching by POS

• tgrep NNS more

Another way to do your sanity check
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See more data?

• tgrep NNS grep . more

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Sentential context (again)

• tgrep wn NNS more

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Searching by syntactic constituent

• tgrep NP more

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Single-line outputs

• tgrep n NP more

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Viewing tree-like output

• tgrep w NP head 20

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Searching for relations between nodes

• tgrep NP lt CC head -16

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tgrep g (whole language)

• A lt B A immediately dominates B
• A lt B A is immediately dominated by B
• A ltlt B A dominates B
• A gtgt B A is dominated by B
• A . B A immediately precedes B
• A .. B A precedes B
• Altlt,B B is the leftmost descendent of A
• AltltB B is the rightmost descendent of A

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Alternation

• node names can be ORed e.g.
• tgrep ClintonGore head

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Character classes

• Regular expressions
• tgrep /Cchild/ egrep . head

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Working towards that weird example

• tgrep /Ppresident/ head

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Combining alternation and a regular expression

• tgrep ClintonGorePpresident/ head

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Searching for a transitive verb

• tgrep -w 'VP ltlt like lt NP ltlt DT' more

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Verbs Particles

• tgrep -w 'VP ltlt kick' gt kicktgrep 'VP ltlt
  /kick./ lt2 PRT' kicktgrep 'VP lt1 VB lt2 PRT'
  kicktgrep -nw 'VP lt1 /VB./ lt2 PRT' kicktgrep
  'VP lt1 (VB lt kick) lt2 PRT' kicktgrep 'VP lt1
  (/VB./ lt kick) lt2 PRT' kick