Combining symbolic and numeric computation on the CRAY

It is now widely accepted that the CRAY supercomputers are very useful for large numeric applications, e.g., Finite Element Analysis, Fluid Dynamics, Image Processing, etc. Much work has been done to make them run efficiently on the CRAY. There has also been some effort to do symbolic computing (Al applications) on these machines. A dialect of LISP, called PSL (Portable Standard Lisp) has been available on the CRAY for some time. However, there has been no effort to effectively combine the two, which is useful for certain kinds of applications, e.g., image understanding. This work demonstrates the mixed computing capability of the CRAY supercomputer by implementing a rule-based segmentation system. The numeric part consists of the FORTRAN subroutines to segment an image into regions, merge and split regions. A forward-chained production system to guide the segmentation process forms to symbolic component. The process of linking the two components is also described.