Cactus Code Thorn CarpetProlongateTest
Author(s)    : Erik Schnetter <schnetter@cct.lsu.edu>
Maintainer(s): Erik Schnetter <schnetter@cct.lsu.edu>
Licence      : GPL
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1. Purpose

Test prolongation in Carpet.

The basic idea is to set up a grid function containing a polynomial of
a certain order of the coordinates.  Prolongatin (interpolation) with
sufficiently high order must preserve these polynomials exactly.