spline(1) User Commands spline(1)
spline - interpolate smooth curve
spline [-aknpx] ...
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 out-
put. The cubic spline output (R. W. Hamming, Numerical Methods for Sci-
entists and Engineers,2nd ed., 349ff) has two continuous derivatives,
and sufficiently many points to look smooth when plotted, for example
-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. Nor-
mally these limits are calculated from the data. Automatic
abcissas start at lower limit (default 0).
See attributes(5) for descriptions of the following attributes:
tab() allbox; cw(2.750000i)| cw(2.750000i) lw(2.750000i)|
lw(2.750000i). ATTRIBUTE TYPEATTRIBUTE VALUE AvailabilitySUNWesu
R. W. Hamming, Numerical Methods for Scientists and Engineers, 2nd ed.
When data is not strictly monotonic in x, spline reproduces the input
without interpolating extra points.
A limit of 1000 input points is enforced silently.
SunOS 5.10 14 Sep 1992 spline(1)