NAME

       KURVP2 - does interpolation for closed parametric curves

SYNOPSIS

       CALL KURVP2 (T, XS, YS, N, X, Y, XP, YP, S, SIGMA)

       The  interpolated  curve  is parameterized by mapping points in the interval [0.,1.] onto an interpolated
       closed curve. The resulting curve has a parametric representation both of whose  components  are  splines
       under tension and functions of the polygonal arc length. The value 0.  is mapped onto (X[1],Y[1]) and the
       value  1.  is also mapped onto (X[1],Y[1]), since the interpolated curve is closed. KURVP1 must be called
       before calling KURVP2.

DESCRIPTION

       T           (real,input) A value to be mapped to a point on the curve. The  interval  [0.,1.]  is  mapped
                   onto  the  curve such that 0. is mapped to (X(1),Y(1)) and 1. is mapped to (X(1),Y(1)), since
                   the interpolated curve is closed. Any interval [TT,TT+1.] maps onto the entire curve.

       XS          (real, oputput) Contains the X coordinate of the interpolated point that T maps to.

       YS          (real, oputput) Contains the Y coordinate of the interpolated point that T maps to.

       N           (integer, input) The number of input data points. (N > 1)

       X           (real, input) An array containing the X values of the input points.

       Y           (real, input) An array containing the Y values of the input points. Adjacent pairs of  points
                   must be distinct.

       XP          (real, input) An array of length N as computed by KURVP1.

       YP          (real, input) An array of length N as computed by KURVP1.

       S           (real, input) An array of length N containing the polygonal arc lengths of the curve.

       SIGMA       (real,  input)  Tension factor. Values near zero result in a cubic spline; large values (e.g.
                   50) result in nearly a polygonal line. A typical value is 1.

ACCESS

       To use KURVP2, load the NCAR Graphics library ngmath.

SEE ALSO

       kurvp1, fitgrid_params.

       Complete documentation for Fitgrid is available at URL
       http://ngwww.ucar.edu/ngdoc/ng/ngmath/fitgrid/fithome.html

COPYRIGHT

       Copyright (C) 2000
       University Corporation for Atmospheric Research

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

UNIX                                               March 1998                                     KURVP2(3NCARG)