4.4BSD/usr/share/man/cat1/spline.0

SPLINE(1)              BSD Reference Manual             SPLINE(1)


NNAAMMEE
       spline - interpolate smooth curve

SSYYNNOOPPSSIISS
       sspplliinnee [ option ] ...

DDEESSCCRRIIPPTTIIOONN
       _S_p_l_i_n_e  takes  pairs of numbers from the standard input as
       abcissas and ordinates of a function.  It produces a simi-
       lar   set,  which  is  approximately  equally  spaced  and
       includes the input set, on the standard output.  The cubic
       spline output (R. W. Hamming, _N_u_m_e_r_i_c_a_l _M_e_t_h_o_d_s _f_o_r _S_c_i_e_n_-
       _t_i_s_t_s _a_n_d _E_n_g_i_n_e_e_r_s_, 2nd ed., 349ff)  has  two  continuous
       derivatives,  and  sufficiently many points to look smooth
       when plotted, for example by _g_r_a_p_h(1G).

       The following options are recognized, each as  a  separate
       argument.

       --aa   Supply abscissas automatically (they are missing from
            the input); spacing is given by the next argument, or
            is  assumed to be 1 if next argument is not a number.

       --kk   The constant _k used in the boundary value computation

              (2nd deriv. at end) = k*(2nd deriv. next to end)

            is set by the next argument.  By default _k = 0.

       --nn   Space output points so that approximately _n intervals
            occur between the lower and upper _x limits.  (Default
            _n = 100.)

       --pp   Make output periodic, i.e. match derivatives at ends.
            First and last input values should normally agree.

       --xx   Next 1 (or 2) arguments are lower (and upper) _x  lim-
            its.   Normally  these limits are calculated from the
            data.   Automatic  abcissas  start  at  lower   limit
            (default 0).

SSEEEE AALLSSOO
       graph(1), plot(1)

DDIIAAGGNNOOSSTTIICCSS
       When data is not strictly monotone in _x_, _s_p_l_i_n_e reproduces
       the input without interpolating extra points.

BBUUGGSS
       A limit of 1000 input points is enforced silently.




7th Edition                     1Q                              1