•The default
object descriptor for molecules in Daylight is structure based.
•There are two
main types of structure based descriptions.
–Feature
keys
+These map well
to observations and to the class nature of organic chemistry.
-However they
require you know the classes up front to set the keys.
-Potentially
there are a large number of possible features.
–Fingerprints
+These are graph
based so do not rely on a priori classification.
+It is possible
to pack them into a fixed width, irrespective of number of features.
-There is no
simple relationship between the pattern and the feature.