/**
* Function: compare_auth
* Purpose: Compares two authority strings
* Author: Tony Rees (Tony.Rees@csiro.au)
* Date created: March 2008
* Inputs: authority string 1 as auth1, authority string 1 as auth2
* Outputs: Numeric similarity value of the 2 strings using weighted n-gram analysis,
* on 0-1 scale (1 = identical - typically after normalization; 0 = no similarity)
* Remarks:
* (1) Invokes function "normalize_auth" on both strings, to compare only normalized
* versions of the same
* (2) Returns blend of 2/3 bigram, 1/3 trigram similarity (bigrams better correspond
* to intuitivesimilarity, however are insensitive to word order, i.e. "Smith et
* Jones" = "Jones et Smith" without some trigram contribution)
* (3) Returns blend of 50% similarity with, and 50% without, stripping of diacritical
* marks - so that the contribution of the latter is reduced but not eliminated
* (4) Is case insensitive (i.e. "de Saedeleer" = "De Saedeleer", etc.)
* (5) Threshold between low / possible / good match is in the area of
* 0-0.3 / 0.3-0.5 / 0.5+.
* @param string $auth1 : authority string 1
* @param string $auth2 : authority string 2
* @return number : between 0 - 1 : (1 = identical - typically after normalization; 0 = no similarity)
*/
public function compare_auth($auth1 = NULL, $auth2 = NULL)
{
if ($auth1 == NULL || $auth2 == NULL) {
return NULL;
} else {
$this->input = array($auth1, $auth2);
$this->debug['compare_auth'][] = "Args: (auth1:{$auth1}) (auth2:{$auth2})";
$n = new Normalize($this->db);
$new_auth1 = $n->normalize_auth($auth1);
$new_auth2 = $n->normalize_auth($auth2);
$this->debug['compare_auth'][] = "1 (new_auth1:{$new_auth1}) (new_auth2:{$new_auth2})";
if ($new_auth1 == $new_auth2) {
$this_auth_match = 1;
$this->debug['compare_auth'][] = "2a (this_auth_match:{$this_auth_match})";
} else {
// create second versions without diacritical marks
#$new_auth1b = $this->translate( $new_auth1, '¡…Õ”⁄¿»Ã“Ÿ¬ Œ‘€ƒÀœ÷‹√—’≈«ÿ', 'AEIOUAEIOUAEIOUAEIOUANOACO');
#$new_auth2b = $this->translate( $new_auth2, '¡…Õ”⁄¿»Ã“Ÿ¬ Œ‘€ƒÀœ÷‹√—’≈«ÿ', 'AEIOUAEIOUAEIOUAEIOUANOACO');
$new_auth1b = $n->utf8_to_ascii($new_auth1);
$new_auth2b = $n->utf8_to_ascii($new_auth2);
// weighted ngram comparison, use 67% n=2, 33% n=3
// use mean of versions with and without diacritical marks (to lessen their effect by 50%)
$temp_auth_match1 = (2 * $this->ngram($new_auth1, $new_auth2, 2) + $this->ngram($new_auth1, $new_auth2, 3)) / 3;
$temp_auth_match2 = 0;
if ($new_auth1 == $new_auth1b && $new_auth2 == $new_auth2b) {
$temp_auth_match2 = $temp_auth_match1;
} else {
$temp_auth_match2 = (2 * $this->ngram($new_auth1b, $new_auth2b, 2) + $this->ngram($new_auth1b, $new_auth2b, 3)) / 3;
}
$this->debug['compare_auth'][] = '2b (temp_auth_match1:$temp_auth_match1) (temp_auth_match2:$temp_auth_match2)';
$this_auth_match = ($temp_auth_match1 + $temp_auth_match2) / 2;
$this->debug['compare_auth'][] = '2c (this_auth_match:$this_auth_match)';
}
}
$this_auth_match = round($this_auth_match, 4);
$this->debug['compare_auth'][] = "Return: {$this_auth_match}";
/* $this->output = $this_auth_match;
return( $this->output );*/
return $this_auth_match;
}
require_once 'classes/class.normalize.php';
$norm = new Normalize();
$norm->set('debug_flag', $_REQUEST['debug']);
$data = $norm->normalize($str);
if ($output == 'xml') {
$data = $norm->getXML();
}
$debug = $norm->debug;
break;
case 'normalize_auth':
require_once 'classes/class.normalize.php';
$db = select_source($source, $classification);
$norm = new Normalize($db);
$norm->set('post_fix', '_' . $source);
$norm->set('source', $source);
$data = $norm->normalize_auth($str);
if ($output == 'xml') {
$data = $norm->getXML();
}
$debug = $norm->debug;
break;
case 'treat_word':
require_once 'classes/class.nearmatch.php';
$nm = new NearMatch();
$strip_ending = $strip_ending == '' ? 0 : $strip_ending;
$normalize = $normalize == '' ? 0 : $normalize;
$data = $nm->treat_word($str, $strip_ending, $normalize);
if ($output == 'xml') {
$data = $nm->getXML();
}
$debug = $nm->debug;
