1KURVP2(3NCARG) NCAR GRAPHICS KURVP2(3NCARG)
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6 KURVP2 - does interpolation for closed parametric curves
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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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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
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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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52 To use KURVP2, load the NCAR Graphics library ngmath.
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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 The use of this Software is governed by a License Agreement.
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68UNIX March 1998 KURVP2(3NCARG)