ADAS Subroutine gspc

       SUBROUTINE GSPC(XA,N,C1,C2,C3,C4)                       
C
       IMPLICIT REAL*8(A-H,O-Z)                               
C
C-----------------------------------------------------------------------
C
C  ****************** FORTRAN77 SUBROUTINE: GSPC ***********************
C
C PURPOSE UNKNOWN
C
C NOTES: THIS ROUTINE IS NOT YET PROPERLY ANNOTATED
C
C UNIX-IDL PORT:
C
C VERSION: 1.1                          DATE: 18-1-96
C MODIFIED: TIM HAMMOND (TESSELLA SUPPORT SERVICES PLC)
C               - PUT UNDER SCCS CONTROL
C
C-----------------------------------------------------------------------
C
      INTEGER             N
      REAL*8              C1(10,9),    C2(10,9),    C3(10,9)
      REAL*8              C4(10,9),    XA(10)