1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
|
# Author:: Lucas Carlson (mailto:lucas@rufy.com)
# Copyright:: Copyright (c) 2005 Lucas Carlson
# License:: LGPL
require "set"
# These are extensions to the String class to provide convenience
# methods for the Classifier package.
class String
# Removes common punctuation symbols, returning a new string.
# E.g.,
# "Hello (greeting's), with {braces} < >...?".without_punctuation
# => "Hello greetings with braces "
def without_punctuation
tr( ',?.!;:"@#$%^&*()_=+[]{}\|<>/`~', " " ) .tr( "'\-", "")
end
# Return a Hash of strings => ints. Each word in the string is stemmed,
# interned, and indexes to its frequency in the document.
def word_hash
word_hash = clean_word_hash()
symbol_hash = word_hash_for_symbols(gsub(/[\w]/," ").split)
return word_hash.merge(symbol_hash)
end
# Return a word hash without extra punctuation or short symbols, just stemmed words
def clean_word_hash
word_hash_for_words gsub(/[^\w\s]/,"").split
end
private
def word_hash_for_words(words)
d = Hash.new(0)
words.each do |word|
word.downcase!
if ! CORPUS_SKIP_WORDS.include?(word) && word.length > 2
d[word.stem.intern] += 1
end
end
return d
end
def word_hash_for_symbols(words)
d = Hash.new(0)
words.each do |word|
d[word.intern] += 1
end
return d
end
CORPUS_SKIP_WORDS = Set.new([
"a",
"again",
"all",
"along",
"are",
"also",
"an",
"and",
"as",
"at",
"but",
"by",
"came",
"can",
"cant",
"couldnt",
"did",
"didn",
"didnt",
"do",
"doesnt",
"dont",
"ever",
"first",
"from",
"have",
"her",
"here",
"him",
"how",
"i",
"if",
"in",
"into",
"is",
"isnt",
"it",
"itll",
"just",
"last",
"least",
"like",
"most",
"my",
"new",
"no",
"not",
"now",
"of",
"on",
"or",
"should",
"sinc",
"so",
"some",
"th",
"than",
"this",
"that",
"the",
"their",
"then",
"those",
"to",
"told",
"too",
"true",
"try",
"until",
"url",
"us",
"were",
"when",
"whether",
"while",
"with",
"within",
"yes",
"you",
"youll",
])
end
|
