<urc>
<title>Nearest Neighbor Tool (NNT)
<description><url>http://www-ad.fsl.noaa.gov/mvpab/hpcs/nnt.html</url>
<abstract>
NNT is a library of high level routines developed to simplify the
parallelization of regular grid based codes. The original motivation for
developing NNT is to parallelize Finite Difference Approximation (FDA)
Numerical Weather Prediction (NWP) models. In addition to supporting
FDA NWP models, NNT should be useful for a general class of grid-based
FDA computations. NNT is being upgraded to support spectral NWP
models as well. It should then be useful for spectral-based grid problems in
other fields, such as signal and image processing.

There are three areas where NNT is particularly beneficial: data and
processor decomposition, input and output, and interprocessor
communications. NNT was designed to allow a user to easily produce
high-performance portable code. Data files created by NNT programs are
also portable.
<environment>
NNT has been ported to:

      Intel iPSC/860
      Intel Paragon
      nCUBE nCUBE2
      Silicon Graphics Challenge
      Sun Multiprocessor (670/690) (SunOS 4.x)
      Network of Unix workstations
      Cray T3D (in progress)

NNT currently provides only a Fortran 77 interface.
<keywords>high level parallel library; regular grid; distributed array;
finite difference approximation; data partitioning; architecture independence
<category>ppt-pplib
<application>weather forecasting
</urc>