Created
June 28, 2015 21:03
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a stupid bigram based segmentizer
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def clean(txt) | |
mark = true | |
txt.each_char.map { |x| | |
if x.ascii_only? and mark | |
mark = false | |
' ' | |
elsif x.ascii_only? | |
nil | |
else | |
mark = true | |
x | |
end | |
}.compact.map { |x| | |
x.nil? ? ' ' : x | |
}.join | |
end | |
def bigram(str) | |
str.split.map {|x| x.each_char.each_cons(2).to_a }.flatten(1) | |
end | |
def stat(bigram) | |
tbl = Hash.new | |
bigram.to_a.each do |a,b| | |
tbl[a] ||= Hash.new(0) | |
tbl[a][b] += 1 | |
end | |
tbl | |
end | |
def maxfreq(tbl) | |
max = 0 | |
tbl.each do |k1,v1| | |
v1.each do |k2,v2| | |
max = v2 if max < v2 | |
end | |
end | |
max | |
end | |
def normalize(len, maxfreq, tbl) | |
new_tbl = Hash.new | |
rec = Math.log(len) | |
norm = Math.log(maxfreq)/rec | |
tbl.each do |k1,v1| | |
v1.each do |k2,v2| | |
new_tbl[k1] ||= Hash.new(0) | |
reced = Math.log(v2.to_f)/rec | |
new_tbl[k1][k2] = reced/norm | |
end | |
end | |
new_tbl | |
end | |
def segm(tbl, txt, prec) | |
segs = [] | |
buf = [] | |
txt.each_char.each_cons(2) do |c1, c2| | |
buf << c1 unless c1 == ' ' | |
if tbl[c1].nil? or tbl[c1][c2] < prec | |
segs << buf.join | |
buf = [] | |
end | |
end | |
segs.reject {|x| x.length == 0 } | |
end |
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require_relative 'ngram' | |
require 'json' | |
txt = clean(File.read('tweets.txt')) | |
cons = bigram(txt) | |
tbl = stat(cons) | |
max = maxfreq(tbl) | |
tbl = normalize(txt.length, max, tbl) | |
segs = segm(tbl, txt, 0.2).reject {|x| x.length <= 1 } | |
File.write('./out.json', segs.to_json) |
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