Value maximum level of recursion for cd_hash

Hi,





I wonder what is the value of maximum level of recursion for cd_hash when a jchem table is created? I would like to match cd_hash with a hash code value of a compound generated by chemaxon.sss.screen.HashCode. I would think that it makes sense if the maximum level of recursion is the same.





Cheers, Péter

Hi Peter,





We use the HashCode.DEFAULT_RECURSION_LEVEL, which has a value of 4.





http://www.chemaxon.com/jchem/doc/api/chemaxon/sss/screen/HashCode.html#DEFAULT_RECURSION_LEVEL





However things are a little bit more complicated, as we also use the information in the fingerprints to make the hash code yet a little more selective.


Please see the following methods where the fingerprint can also be specified:





http://www.chemaxon.com/jchem/doc/api/chemaxon/sss/screen/HashCode.html#getHashCode(chemaxon.struc.Molecule,%20int[])


http://www.chemaxon.com/jchem/doc/api/chemaxon/sss/screen/HashCode.html#getHashCode(chemaxon.struc.Molecule,%20int[],%20int)





Obtaining the fingerprints requires a little bit more code.


The class generating the fingerprints on insert (CombinedFingerprint) is not part of the public API at the moment (we will fix this).


Quick example code for a regular (molecule) table with no structural keys:

Code:

chemaxon.util.ConenctionHandler conh = ...;  // the connection to the database String tableName = ... ; //the name of the table Moelcule mol = ...;  //the Molecule chemaxon.reaction.Standardizer standardizer=TableInfo.getStandardizer(conh, tableName); chemaxon.sss.screen.CombinedFingerprint cfp=new CombinedFingerprint(numberOfStrucFPCols, null, standardizer,                     numberOfCFpCols, numberOfEdges, numberOfOnes,                     false); int[][] fingerprints = cfp.getCombinedFingerprints(mol, null, false, false, true); //checking for timeout in ring calculation: boolean noRingInfoInFP = cfp.isRingInfoIncomplete(); int[] fingerprint = noRingInfoInFP ? fingerprints[0] : fingerprints[1];

You can check the fingerprint parameters for any table using the following command:

Code:

jcman t <table_name>

Best regards,





Szilard

Hi Szilard,





Thanks, this works fine. I could get the fingerprints and the hashcode.





Cheers, Péter