Field-based similarity search system and method

Abstract

A field-based similarity search system includes an input device which inputs a query molecule, and a processor which partitions a conformational space of the query molecule into a fragment graph including an acyclic graph including plural fragment nodes connected by rotatable bond edges, computes a property field on fragment pairs of fragments of the query molecule from the fragment graph, the property field including a local approximation of a property field of the query molecule, constructs a set of features of the fragment pairs based on the property field, the features including a set of local, rotationally invariant, and moment-based descriptors generated from all conformations of the fragment graph of the query molecule, and weights the descriptors according to importance as perceived from a training set of descriptors to generate a context-adapted descriptor-to-key mapping which maps the set of descriptors to a set of feature keys.

What is claimed is: 
     
         1 . A field-based similarity search system, comprising:
 an input device which inputs a query molecule; and   a processor which:
 partitions a conformational space of said query molecule into a fragment graph comprising an acyclic graph including plural fragment nodes connected by rotatable bond edges; 
 computes a property field on fragment pairs of fragments of said query molecule from said fragment graph, said property field comprising a local approximation of a property field of said query molecule; 
 constructs a set of features of said fragment pairs based on said property field, said features comprising a set of local, rotationally invariant, and moment-based descriptors generated from all conformations of said fragment graph of said query molecule; and 
 weights said descriptors according to importance as perceived from a training set of descriptors to generate a context-adapted descriptor-to-key mapping which maps said set of descriptors to a set of feature keys comprising indices that label grid cells in discriminant space, 
   wherein said processor partitions said conformational space by selecting of a set of bonds in said molecule to cleave.   
     
     
         2 . The field-based similarity search system of  claim 1 , wherein said processor further:
 aligns fragment pairs of a candidate molecule stored in a feature database to said query molecule.   
     
     
         3 . The field-based similarity search system of  claim 2 , wherein said processor further:
 assembles said aligned candidate molecule fragment pairs to construct a full aligned candidate molecule.   
     
     
         4 . The field-based similarity search system of  claim 3 , further comprising:
 a display device for displaying said full aligned candidate molecule.