ADAS Subroutine h4gspc

C
       subroutine h4gspc( istdim ,
     &                    xa     , n      , 
     &                    c1     , c2     , c3     , c4
     &                  )
c-----------------------------------------------------------------------
c
c  **************** fortran77 subroutine: h4gspc.for *********************
c
c  purpose: generate precursors of spline coefficients suitable
c           for both forward and backward interpolation
c
c  calling program: various
c
c  
c  input : (i*4)  istdim  = dimensionality for splining arrays
c
c  input : (r*8)  xa(i)   = set of knots
c  input : (i*4)  n       = number of knots  (n.le.istdim)
c  
c  output: (r*8)  c1(i,j) = 1st spline coefficient precursor
c  output: (r*8)  c2(i,j) = 2nd spline coefficient precursor
c  output: (r*8)  c3(i,j) = 3rd spline coefficient precursor
c  output: (r*8)  c4(i,j) = 4th spline coefficient precursor
c
c  routines:
c          routine    source    brief description
c          -------------------------------------------------------------
c          h4spl3     adas      
c          i4unit     adas      fetch unit number for output of messages
c
c  author:  Hugh P. Summers, University of Strathclyde
c           JA7.08
c           Tel.: +44 (0)141-548-4196
c
c  date:    24 July 2002
c
c
c  version: 1.1   Hugh Summers  24/07/02
c  modified:      first release
c
c-----------------------------------------------------------------------
      INTEGER             ISTDIM,      N
      REAL*8              C1(ISTDIM,ISTDIM-1),      C2(ISTDIM,ISTDIM-1)
      REAL*8              C3(ISTDIM,ISTDIM-1),      C4(ISTDIM,ISTDIM-1)
      REAL*8              XA(ISTDIM)