SPLINE(1g,C)                AIX Commands Reference                 SPLINE(1g,C)



-------------------------------------------------------------------------------
spline



PURPOSE

Interpolates a smooth curve.

SYNTAX


                                         +-------------------------+
                            +------------|             +---------+ |-------+
         +- -k 0 -n 100 -+  |            +- -x lowlim -|         |-+       |
spline --| +-----------+ |--|                          +- uplim -+         |--|
         +-|  -k num   |-+  |      +-- 1 --+   +- -x 0 ------------------+ |
          ^|  -p       ||   +- -a -|       |---|             +---------+ |-+
          ||  -n num   ||          +- num -+   +- -x lowlim -|         |-+
          |+-----------+|                                    +- uplim -+
          +-------------+


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 coordinates 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

-a num           Supplies abscissas automatically; spacing is given by the next
                 parameter or is assumed to be 1 if the next parameter is not a
                 number.

-k num           Uses the constant num in the boundary value calculation:

                    y0 =ky1 , y =numy

                 The default for num is zero.






Processed November 8, 1990       SPLINE(1g,C)                                 1






SPLINE(1g,C)                AIX Commands Reference                 SPLINE(1g,C)



-n num           Spaces output points so that approximately 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.

-x lowlim[ 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.












































Processed November 8, 1990       SPLINE(1g,C)                                 2