NAME

       CSSGRIDD - tension spline interpolation on a sphere.

SYNOPSIS

       CALL CSSGRIDD (N, RLAT, RLON, F, NI, NJ, PLAT, PLON, FF, IWK, RWK, IER)

DESCRIPTION

       N           (integer,input) The number of input data points (N > 2).

       RLAT        (double precision, input) An array containing the latitudes of the input data,
                   expressed in degrees.  The first three points must not be collinear (lie on  a
                   common great circle).

       RLON        (double  precision,  input)  An  array  containing the longitudes of the input
                   data, expressed in degrees.

       F           (double  precision,  input)  An  array  containing  data  values.  F(I)  is  a
                   functional value at (RLAT(I),RLON(I)) for I = 1 to N.

       NI          (integer, input) The number of rows in the uniform output grid. NI can be 1.

       NJ          (integer,  input)  The number of columns in the uniform output grid. NJ can be
                   1.

       PLAT        (double precision, intput) An array of length NI containing the latitudes  the
                   output grid lines.  The values in PLAT should be in degrees.

       PLON        (double precision, intput) An array of length NJ containing the longitudes the
                   output grid lines.  The value in PLON should be in degrees.

       FF          (double  precision,  output)  An  NI  by  NJ  array  containing  the   desired
                   interpolated  values.  FF(I,J)  is  the  interpolated  value at the coordinate
                   specified by PLAT(I) and PLON(J) for I = 1 to NI and J = 1 to NJ.

       IWK         (integer, input) An integer workspace of length 27*N.

       RWK         (double precision, input) A work array dimensioned for 13*N.   Note  that  RWK
                   must be typed DOUBLE PRECISION.

       IER         (integer,  output)  An  error  return value.  If IER is returned as 0, then no
                   errors were detected. If IER is non-zero, then  refer  to  the  man  page  for
                   cssgrid_errors for details.

USAGE

       CSSGRIDD is called to find an interpolating tension spline for data randomly positioned on
       a sphere.  CSSGRIDD is a double precision version of CSSGRID.

ACCESS

       To use CSSGRIDD, load the NCAR Graphics library ngmath.

SEE ALSO

       css_overview, csstri, cssgrid, cssgrid_errors

       Complete documentation for Cssgrid is available at URL
       http://ngwww.ucar.edu/ngdoc/ng/ngmath/cssgrid/csshome.html

COPYRIGHT

       Copyright (C) 2000
       University Corporation for Atmospheric Research

       The use of this Software is governed by a License Agreement.