ADAS Subroutine h4spl3

C
       subroutine h4spl3( istdim ,
     &                    n      , h      , w     
     &                  )
c-----------------------------------------------------------------------
c
c  **************** fortran77 subroutine: h4spl3.for *******************
c
c  purpose: calculate splines with various end conditions
c
c  calling program: h4gspc
c
c
c  notes: (1) uses labelled common  /espl3/
c         (2) conditions at 1st & nth nodes controlled by iend1 & iendn    
c           iend = 1 : specified d log(y) ie. dy/y at node stored in 
c                    appropriate vector
c                = 2 : zero curvature                                          
c                = 3 : constant curvature                                      
c                = 4 : matched to specified functional form in terms of        
c                      two parameters a and b such that                        
c                        funct = p(1)*a+q(1)*b                          
c                        1st deriv. = p(2)*a+q(2)*b                          
c                        2nd deriv. = p(3)*a+q(3)*b                          
c                        where a1,b1,p1,q1 are used for 1st node and             
c                        an,bn,pn,qn for nth node                                
c
c  input : (i*4)  istdim  = dimensionality for splining arrays
c
c  input : (i*4)  n    = number of knots
c  input : (r*8)  h()  = intervals between knots
c  
c  output: (r*8)  w(,) = spline matrix
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              H(ISTDIM),   W(ISTDIM,ISTDIM)