ADAS Subroutine fsplin

      SUBROUTINE FSPLIN(N,X,F,B,H,M,XNEW,FSPL)
      IMPLICIT REAL*8 (A-H,O-Z)
C-----------------------------------------------------------------------
C     PURPOSE: Calculates M values of function FSPL(XNEW)
C              using spline approximation
C-----------------------------------------------------------------------
C
C ADAS305 version. Developed from JETSHP.STARK.FORT (H P Summers).
C
C VERSION  : 1.1
C DATE     : 24-02-2005
C MODIFIED : Martin O'Mullane
C             - First version.
C
C VERSION  : 1.2
C DATE     : 16-05-2007
C MODIFIED : Allan Whiteford
C             - Updated comments as part of subroutine documentation
C               procedure.
C
C----------------------------------------------------------------------
      INTEGER             M,           N
      REAL*8              B(N),        F(N),        FSPL(M),     H(N)
      REAL*8              X(N),        XNEW(M)