similarity.sql.in

-- Similarity functions
Create or Replace FUNCTION _OCSCHEMA_.tanimoto(bit, bit)
 Returns real AS '
Select _OCSCHEMA_.nbits_set($1 & $2)::real /
      (_OCSCHEMA_.nbits_set($1 & ~$2) + _OCSCHEMA_.nbits_set($2 & ~$1) +
       _OCSCHEMA_.nbits_set($1 & $2))::real;
' LANGUAGE sql IMMUTABLE;
Comment On FUNCTION _OCSCHEMA_.tanimoto(bit, bit)
 Is 'standard tanimoto similarity of fingerprints';

/*
Create or Replace FUNCTION _OCSCHEMA_.tani2(bit, bit)
 Returns real AS '
Select _OCSCHEMA_.nbits_set($1 & $2)::real /
      (_OCSCHEMA_.nbits_set($1) + _OCSCHEMA_.nbits_set($2) - _OCSCHEMA_.nbits_set($1 & $2))::real;
' LANGUAGE sql IMMUTABLE;
Comment On FUNCTION _OCSCHEMA_.tani2(bit, bit)
 Is 'According to the Daylight Theory Manual.';

Create or Replace FUNCTION _OCSCHEMA_.tani3(bit, bit)
 Returns real AS '
Select _OCSCHEMA_.nbits_set($1 & $2)::real /
       _OCSCHEMA_.nbits_set($1 | $2)::real;
' LANGUAGE sql IMMUTABLE;
Comment On FUNCTION _OCSCHEMA_.tani3(bit, bit)
 Is 'According to Sayle';
*/

Create or Replace FUNCTION _OCSCHEMA_.euclid(bit, bit)
 Returns real AS '
Select sqrt((_OCSCHEMA_.nbits_set($1 & $2) + _OCSCHEMA_.nbits_set(~$1 & ~$2))::real /
  length($1))::real;
' LANGUAGE sql IMMUTABLE;
Comment On FUNCTION _OCSCHEMA_.euclid(bit, bit)
 Is 'standard euclid similarity of fingerprints';

Create or Replace FUNCTION _OCSCHEMA_.hamming(bit, bit)
 Returns real AS '
Select ((_OCSCHEMA_.nbits_set($1 & ~$2) + _OCSCHEMA_.nbits_set(~$1 & $2))::real /
   length($1))::real;
' LANGUAGE sql IMMUTABLE;
Comment On FUNCTION _OCSCHEMA_.hamming(bit, bit)
 Is 'standard hamming similarity of fingerprints';

Create or Replace FUNCTION _OCSCHEMA_.tversky(bit, bit, real, real)
 Returns real AS '
Select _OCSCHEMA_.nbits_set($1 & $2)::real /
  ($3*_OCSCHEMA_.nbits_set($1 & ~$2) + $4*_OCSCHEMA_.nbits_set($2 & ~$1) +
      _OCSCHEMA_.nbits_set($1 & $2))::real;
' LANGUAGE sql IMMUTABLE;
Comment On FUNCTION _OCSCHEMA_.tversky(bit, bit, real, real)
 Is 'standard tversky similarity of fingerprints';

Create or Replace FUNCTION _OCSCHEMA_.similarity(bit, bit)
 Returns real AS '
Select _OCSCHEMA_.tversky($1, $2, 0.5, 0.5);
' LANGUAGE sql IMMUTABLE;
Comment On FUNCTION _OCSCHEMA_.similarity(bit, bit)
 Is 'standard dice similarity of fingerprints';
                                                                                
Create or Replace FUNCTION _OCSCHEMA_.similarity(Text, Text)
 Returns real AS '
Select _OCSCHEMA_.tversky(_OCSCHEMA_.public166keys($1), _OCSCHEMA_.public166keys($2), 0.5, 0.5);
' LANGUAGE sql IMMUTABLE;
Comment On FUNCTION _OCSCHEMA_.similarity(Text, Text)
 Is 'standard dice similarity of smiles using public166key';