15 SUBROUTINE nspline (N, X, Y, B, C, D)
17 REAL X(N), Y(N), B(N), C(N), D(N)
48 INTEGER NM1, NM2, IB, I
52 IF ( n .LT. 2 )
RETURN
58 IF(x(ip1).LE.x(i))
then
60 write(6,9001) (x(ii),ii=1,n)
61 zbomb=sqrt(-1.0/(x(1)*x(1)))
63 write(6,*)
' nspline -- code stop.'
66 >
' ? UNORDERED ORDINATE ARRAY PASSED TO SPLINE SUBROUTINE:')
67 9001
FORMAT(1x,5(1x,1pe12.5))
71 IF ( n .LT. 3 )
GO TO 50
78 c(2) = (y(2) - y(1))/d(1)
81 b(i) = 2.*(d(i-1) + d(i))
82 c(i+1) = (y(i+1) - y(i))/d(i)
95 b(i) = b(i) - t*d(i-1)
96 c(i) = c(i) - t*c(i-1)
102 c(nm1) = c(nm1)/b(nm1)
105 c(i) = (c(i) - d(i)*c(i+1))/b(i)
112 b(n) = (y(n) - y(nm1))/d(nm1) + d(nm1)*(c(nm1) + 2.*c(n))
114 b(i) = (y(i+1) - y(i))/d(i) - d(i)*(c(i+1) + 2.*c(i))
115 d(i) = (c(i+1) - c(i))/d(i)
122 50 b(1) = (y(2)-y(1))/(x(2)-x(1))