Table 1.

Software function comparison in terms of flexibility and extensibility.

Software Functions	Sequence Types	Extensibility
UltraPse	DNA, RNA, Protein, User-defined types	Users can define their own sequence types, representation modes and physicochemical properties
PseAAC-General [46]	Protein	Users can define their own representation modes
PseAAC-Builder [45]	Protein	No extensibility
Pse-In-One [52]	DNA, RNA, Protein	Users can define their own physicochemical properties
PseKNC [48]	DNA, RNA	Users can define their own physicochemical properties
PseKNC-General [49]	DNA, RNA	Users can define their own physicochemical properties