module BlackStack::Strings::Comparing


Fuzzy String Comparsion Functions: How similar are 2 strings that are not exactly equal.


Public Class Methods

levenshtein_distance(s, t) click to toggle source

retorna 0 si los strings son iguales stackoverflow.com/questions/16323571/measure-the-distance-between-two-strings-with-ruby

# File lib/functions.rb, line 149
def self.levenshtein_distance(s, t)  
  s.downcase!
  t.downcase!

  m = s.length
  n = t.length
  return m if n == 0
  return n if m == 0
  d = Array.new(m+1) {Array.new(n+1)}

  (0..m).each {|i| d[i][0] = i}
  (0..n).each {|j| d[0][j] = j}
  (1..n).each do |j|
    (1..m).each do |i|
      d[i][j] = if s[i-1] == t[j-1]  # adjust index into string
                  d[i-1][j-1]       # no operation required
                else
                  [ d[i-1][j]+1,    # deletion
                    d[i][j-1]+1,    # insertion
                    d[i-1][j-1]+1,  # substitution
                  ].min
                end
    end
  end
  d[m][n]
end
max_sardi_distance(s) click to toggle source

retorna la cantidad de palabras con mas de 3 caracteres que se encuentran en el parametro s

# File lib/functions.rb, line 177
def self.max_sardi_distance(s)
  s.downcase!
  s.gsub!(/-/,' ')
  ss = s.scan(/\b([a-z]+)\b/)
  n = 0
  ss.each { |x|
    x = x[0]
    if (x.size > 3) # para evitar keywords triviales como 'and'
      n += 1
    end
  }
  n
end
sardi_distance(s, t) click to toggle source

retorna la cantidad de palabras con mas de 3 caracteres del parametro s que se encuentran en el parametro t

# File lib/functions.rb, line 192
def self.sardi_distance(s, t)
  s.downcase!
  t.downcase!
  s.gsub!(/-/,' ')
  t.gsub!(/-/,' ')
  max_distance = max_sardi_distance(s)  
  ss = s.scan(/\b([a-z]+)\b/)
  tt = t.scan(/\b([a-z]+)\b/)
  n = 0
  ss.each { |x|
    x = x[0]
    if (x.size > 3) # para evitar keywords triviales como 'and'
      if ( tt.select { |y| y[0] == x }.size > 0 )
        n += 1
      end
    end
  }
  return max_distance - n
end