Produces a reference to a subroutine which evaluates a polynomial passing through the specified points
with the specified derivatives: (x0,y0,yp0), ...
The polynomial will be of high degree and may wobble unexpectedly. Use the Hermite splines
described below and in Hermite.pm for most graphing purposes.
$poly = hermit([$x0,$x1...],[$y0,$y1...],[$yp0,$yp1,...]);yields the y value at 34.
$y = &$poly(34);
References to three arrays, specifying respectively the x, y and y' values to be interpolated by the Hermite polynomial. All of the parameters are required. There are no defaults.
A reference to a function of one variable representing the polynomial.
The Hermite polynomial objects give the most versatile version of Hermite spline approximation. Except in rare cases they are likely to be the most appropriate choice for specifying graphs.
This subroutine is defined in [PGnumericalmacros.pl].