spline
PURPOSE
Interpolates smooth curve.
SYNOPSIS
spline [ options ]
DESCRIPTION
The spline command reads from the standard input pairs of
numbers that represent the coordinates of a point on an
x,y axis. From this input, spline calculates the coordi-
nates of points to form a smooth curve through the points
in the input set. It then writes these points to
standard output. The output points are approximately
equally spaced and includes the points that you provided
as input. The cubic spline output has two continuous
derivatives, and enough points so that when plotted with
the graph command it looks smooth.
When data is not strictly monotone in x, spline
reproduces the input without interpolating extra points.
You can only use 1,000 input points.
FLAGS
-anum Supplies abscissas automatically;
spacing is given by the next parameter
or is assumed to be 1 if the next param-
eter is not a number.
-knum Uses the constant num in the boundary
value calculation:
y[0] =ky[1] , y =numy
The default for num is zero.
-nnum Spaces output points so that approxi-
mately num intervals occur between the
lower and upper x limits (set with the
-x flag). The default num is 100.
-p Makes output periodic, that is, matches
derivatives at ends. First and last
input values should normally agree.
-xlowlim[uplim] Sets lower and upper x limits as lowlim
and uplim. Normally, these limits are
calculated from the data. Automatic
abscissas start at lower limit, defaults
to zero.
RELATED INFORMATION
The following command: "graph."