Cactus Code Thorn LocalInterp
Authors    : Jonathan Thornburg <jthorn@aei.mpg.de>,
             incorporating parts of the old PUGHInterp by
             Thomas Radke <tradke@aei.mpg.de>, which in turn draws
             on older code by Paul Walker and optimization ideas
             from Erik Schnetter <schnetter@uni-tuebingen.de>
Maintainer : Jonathan Thornburg <jthorn@aei.mpg.de>
CVS info   : $Header$
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Purpose of the thorn:

This thorn does processor-local interpolation of N-dimensional data
arrays.  In general there may be many input arrays (all defined on the
same uniform Cartesian grid) all being interpolated to the same set
of interpolation points.

This thorn actually packages together two separate local interpolators:
* One written by Thomas Radke in early 2001, with the operators
     "first order uniform cartesian"
     "second order uniform cartesian",
     "third order uniform cartesian"
  for the CCTK_InterpLocal() interpolation API.  (This code formerly
  lived in the PUGHInterp thorn, but turned to have very little to do
  with PUGH, so it's been moved here.)  This code lives in the subdirectory
  src/UniformCartesian/ .
* One written by Jonathan Thornburg in winter 2001-2002, with the
  operators
     "Lagrange polynomial interpolation (tensor product)"
     "Lagrange polynomial interpolation (maximum degree)"
  for the CCTK_InterpLocalUniform() interpolation API.  The operators
     "Lagrange polynomial interpolation"
     "generalized polynomial interpolation"
  are also both accepted as a synonyms for
     "Lagrange polynomial interpolation (tensor product)"
  This code lives in the subdirectory src/GeneralizedPolynomial-Uniform/ .

See the README files in the individual interpolators' directories
for more information.

We plan to eventually phase out the CCTK_InterpLocal() API.  We may
also phase out its interpolator, or we may move this to the newer
CCTK_InterpLocalArrays() API.