1KURVP2(3NCARG)                   NCAR GRAPHICS                  KURVP2(3NCARG)
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NAME

6       KURVP2 - does interpolation for closed parametric curves
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SYNOPSIS

9       CALL KURVP2 (T, XS, YS, N, X, Y, XP, YP, S, SIGMA)
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11       The interpolated curve is parameterized by mapping points in the inter‐
12       val [0.,1.] onto an interpolated closed curve. The resulting curve  has
13       a  parametric representation both of whose components are splines under
14       tension and functions of the polygonal arc length.  The  value  0.   is
15       mapped   onto  (X[1],Y[1])  and  the  value  1.  is  also  mapped  onto
16       (X[1],Y[1]), since the interpolated curve is  closed.  KURVP1  must  be
17       called before calling KURVP2.
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DESCRIPTION

20       T           (real,input)  A value to be mapped to a point on the curve.
21                   The interval [0.,1.] is mapped onto the curve such that  0.
22                   is  mapped  to (X(1),Y(1)) and 1. is mapped to (X(1),Y(1)),
23                   since  the  interpolated  curve  is  closed.  Any  interval
24                   [TT,TT+1.] maps onto the entire curve.
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26       XS          (real,  oputput)  Contains the X coordinate of the interpo‐
27                   lated point that T maps to.
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29       YS          (real, oputput) Contains the Y coordinate of  the  interpo‐
30                   lated point that T maps to.
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32       N           (integer, input) The number of input data points. (N > 1)
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34       X           (real, input) An array containing the X values of the input
35                   points.
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37       Y           (real, input) An array containing the Y values of the input
38                   points. Adjacent pairs of points must be distinct.
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40       XP          (real, input) An array of length N as computed by KURVP1.
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42       YP          (real, input) An array of length N as computed by KURVP1.
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44       S           (real, input) An array of length N containing the polygonal
45                   arc lengths of the curve.
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47       SIGMA       (real, input) Tension factor. Values near zero result in  a
48                   cubic  spline;  large  values  (e.g. 50) result in nearly a
49                   polygonal line. A typical value is 1.
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ACCESS

52       To use KURVP2, load the NCAR Graphics library ngmath.
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SEE ALSO

55       kurvp1, fitgrid_params.
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57       Complete documentation for Fitgrid is available at URL
58       http://ngwww.ucar.edu/ngdoc/ng/ngmath/fitgrid/fithome.html
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61       Copyright (C) 2000
62       University Corporation for Atmospheric Research
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64       This documentation is free software; you  can  redistribute  it  and/or
65       modify  it  under  the  terms of the GNU General Public License as pub‐
66       lished by the  Free  Software  Foundation;  either  version  2  of  the
67       License, or (at your option) any later version.
68
69       This  software  is  distributed in the hope that it will be useful, but
70       WITHOUT ANY  WARRANTY;  without  even  the  implied  warranty  of  MER‐
71       CHANTABILITY  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
72       Public License for more details.
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74       You should have received a copy of the GNU General Public License along
75       with  this  software;  if  not,  write to the Free Software Foundation,
76       Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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81UNIX                              March 1998                    KURVP2(3NCARG)
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