`
``
use Math::Derivative qw(Derivative1 Derivative2);
@dydx = Derivative1(\@x, \@y);
@d2ydx2 = Derivative2(\@x, \@y);
@d2ydx2 = Derivative2(\@x, \@y, $yp0, $ypn);
`

The functions must be imported by name.
*Derivative1()*

Take the references to two arrays containing the x and y ordinates of
the data, and return an array of the 1st derivative at the given x ordinates.

*Derivative2()*

Take references to two arrays containing the x and y ordinates of the
data and return an array of the 2nd derivative at the given x ordinates.

You may optionally give values to use as the first dervivatives at the
start and end points of the data. If you don’t, first derivative values
will be calculated from the arrays for you.