spline(1)                                                          User Commands                                                         spline(1)

NAME

       spline - interpolate smooth curve

SYNOPSIS

       spline [-aknpx] ...

DESCRIPTION

       spline takes pairs of numbers from the standard input as abcissas and ordinates of a function. It produces a similar set, which is approxi-
       mately equally spaced and includes the input set, on the standard output. The cubic spline output (R. W.  Hamming,  Numerical  Methods  for
       Scientists  and  Engineers,2nd  ed.,  349ff)  has two continuous derivatives, and sufficiently many points to look smooth when plotted, for
       example by graph(1).

OPTIONS

       -a       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.

       -k       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.

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

       -p       Make output periodic, that is, match derivatives at ends. First and last input values should normally agree.

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

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE         |      ATTRIBUTE VALUE        |
       +-----------------------------+-----------------------------+
       |Availability                 |SUNWesu                      |
       +-----------------------------+-----------------------------+

SEE ALSO

       graph(1), attributes(5)

       R. W. Hamming, Numerical Methods for Scientists and Engineers, 2nd ed.

DIAGNOSTICS

       When data is not strictly monotonic in x, spline reproduces the input without interpolating extra points.

BUGS

       A limit of 1000 input points is enforced silently.

SunOS 5.10                                                          14 Sep 1992                                                          spline(1)