!=====================================================================
! NGMA: Ngmath Library, A Collection of Interpolators and Approximators
!=====================================================================
!
! The ngmath library is a collection of mathematical procedures.
!
! As of July, 1999 the ngmath library contains a collection of
! interpolators and approximators for 1-d, 2-d, and 3-d data.
!
! The packages are:
!
! [A] natgrid - a 2-d random data interpolation package based on
! Dave Watson's package nngridr.
!
! [B] dsgrid - a 3-d random data interpolator based on a simple
! inverse distance weighting algorithm.
!
! [C] fitgrid - an interpolation package for 1-d and 2-d gridded data
! based on Alan Cline's package Fitpack
!
! [D] csagrid - an approximation package for 1-d, 2-d, and 3-d random
! data based on David Fulker's package Splpack.
!
! [E] cssgrid - an interpolation package for random data on the
! surface of a sphere.
!
! [F] shgrid - an interpolation package for random data in 3-space.
!
!---------------------------------------------------------------------
! [A] NatGrid: an interpolation package for 2-D random data
!---------------------------------------------------------------------
!
! NG_NATGRIDS - primary function for gridding.
!
! NG_NNSETI - set INTEGER parameter values.
! NG_NNGETI - retrieve values for INTEGER parameters.
!
! NG_NNSETR - set REAL parameter values.
! NG_NNGETR - retrieve values for REAL parameters.
!
! NG_NNSETC - set CHARACTER valued parameters.
! NG_NNGETC - retrieve values for CHARACTER parameters.
!
! NG_NNGETASPECTS - get aspect values, if calculated.
! NG_NNGETSLOPES - get slope values, if calculated.
!
! NG_NNPNTINITS - initiate single point mode.
! NG_NNPNTS - interpolate at a single point.
! NG_NNPNTEND - terminate single point mode.
!
! NG_NNGETWTS - get neighbors and weights.
!
! NG_NATDISP - a tool for displaying NatGrid algorithm
!
!---------------------------------------------------------------------
! [B] DsGrid: an interpolation package for 3-D random data
!---------------------------------------------------------------------
!
! NG_DSGRID2S - primary function for gridding 2D data.
! NG_DSGRID3S - primary function for gridding 3D data.
!
! NG_NNSETI - set INTEGER parameter values.
! NG_NNGETI - retrieve values for INTEGER parameters.
!
! NG_NNSETR - set REAL parameter values.
! NG_NNGETR - retrieve values for REAL parameters.
!
! NG_NNSETC - set CHARACTER valued parameters.
! NG_NNGETC - retrieve values for CHARACTER parameters.
!
! NG_DSPNT2S - interpolate 2D data at specified individual points.
! NG_DSPNT3S - interpolate 3D data at specified individual points.
!
!---------------------------------------------------------------------
! [C] FitGrid: an interpolation package for 1-D and 2-D gridded data
!---------------------------------------------------------------------
!
!---------------------------
! 1-D non-periodic functions
!---------------------------
!
! NG_CURV1 - calculate values for CURV2 usage
! NG_CURV2 - interpolate at a specified point (func)
! NG_CURVI - integrate a spline curve (func)
! NG_CURVD - calculate a derivative at a specified point (func)
!
! NG_CURVS - calculate values for a smoothing spline
!
!-----------------------
! 1-D periodic functions
!-----------------------
!
! NG_CURVP1 - calculate values for CURVP2 usage
! NG_CURVP2 - interpolate a periodic function at a specified point (func)
! NG_CURVPI - integrate a periodic spline curve (func)
!
! NG_CURVPS - calculate values for a smoothing spline
!
!--------------------
! Spline in the plane
!--------------------
!
! NG_CURVS1 - calculate values for CURVS2 usage
! NG_CURVS2 - interpolate value for a smoothing spline under tension
!
!-------------------------------
! Parametric curves in the plane
!-------------------------------
!
! NG_KURV1 - calculate values for KURV2 usage
! NG_KURV2 - does interpolation for parametric curves
! NG_KURVD - interpolation and derivatives for parametric curves
!
!--------------------------------------
! Closed parametric curves in the plane
!--------------------------------------
!
! NG_KURVP1 - calculate values for KURVP2 usage
! NG_KURVP2 - does interpolation for closed parametric curves
! NG_KURVPD - interpolation and derivatives for closed parametric curves
!
!-----------------
! 2-D gridded data
!-----------------
!
! NG_SURF1 - calculate values for SURF2 usage
! NG_SURF2 - 2D interpolation for gridded data (func)
!
!---------------------------------------------------------------------
! [D] CsaGrid: a cubic spline approximation for 1-, 2-, or 3-d random data
!---------------------------------------------------------------------
!
!----------------
! One-dimensional
!----------------
!
! NG_CSA1S - simple entry
! NG_CSA1XS - expanded entry
!
!----------------
! Two-dimensional
!----------------
!
! NG_CSA2S - simple entry, gridded output
! NG_CSA2XS - expanded entry, gridded output
!
! NG_CSA2LS - simple entry, list output
! NG_CSA2LXS - expanded entry, list output
!
!------------------
! Three-dimensional
!------------------
!
! NG_CSA3S - simple entry, gridded output
! NG_CSA3XS - expanded entry, gridded output
!
! NG_CSA3LS - simple entry, list output
! NG_CSA3LXS - expanded entry, list output
!
!---------------------------------------------------------------------
! [E] cssgrid - interpolate random data on the surface of a sphere
!---------------------------------------------------------------------
!
! NG_CSSGRID - interpolation on a sphere
! NG_CSSGRIDD - interpolation on a sphere (double precision entry)
!
! NG_CSSTRI - calculates Delaunay triangulation
! NG_CSSTRID - calculates Delaunay triangulation (double precision entry)
!
! NG_CSVORO - calculates Voronoi polygons
! NG_CSVOROD - calculates Voronoi polygons (double precision entry)
!
! NG_CSS2C - converts from lat/lon to Cartesian coordinates
! NG_CSS2CD - converts from lat/lon to Cartesian coordinates (double precision entry)
!
! NG_CSC2S - converts from Cartesian to lat/lon coordinates
! NG_CSC2SD - converts from Cartesian to lat/lon coordinates (double precision entry)
!
! NG_CSSETI - set values for integer-valued parameters
! NG_CSGETI - retrieve values for integer-valued parameters
!
! NG_CSSETR - set values for real valued parameters
! NG_CSGETR - retrieve values for real valued parameters
!
! NG_CSSETD - set values for double precision-valued parameters
! NG_CSGETD - retrieve values for double precision-valued parameters
!
!---------------------------------------------------------------------
! [F] ShGrid: interpolate random data in 3-space
!---------------------------------------------------------------------
!
! NG_SHGRID - interpolate 3D random data
!
! NG_SHGETNP - find nearest points to a given point in 3-space
!
! NG_SHSETI - set values for integer control paramaters
! NG_SHGETI - retrieve values for integer control paramaters
!
!=====================================================================
! Refer "NCAR menu" for interfacing NGMATH in detail
!=====================================================================