The ability to search the database for custom Annotation values makes HIVbase's Query Engine
very powerful. However, it's made even more powerful by the introduction of custom functions.
With HIVbase's User Defined Functions, a user can dynamically add information about the
sequences within her database. For instance, a user can display the number of glycosylation sites
that occur within her sequences by defining a special 'Count' function.
Similarly, the 'Exists' function can be tailored to let the user know if a particular pattern of
Amino Acids exists within her sequences.
These customized functions then become columns within
the user's current Query Results just like an Annotation or any other data field.
There is a nearly unlimited amount of additional information
that can be extracted from sequence data by use of HIVbase's User Defined Functions.
