1CURVS2(3NCARG)                   NCAR GRAPHICS                  CURVS2(3NCARG)
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NAME

6       CURVS2  - calculates an interpolated value for a smoothing spline under
7       tension at a given point.
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SYNOPSIS

10       FUNCTION CURVS2(T,N,PARAM,X,Y,XP,YP,SIGMA,XO,YO)
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12       This subroutine is a companion to CURV1S which must  be  called  before
13       calling this subroutine.  CURV2S calculates an interpolated value for a
14       smoothing spline under tension at a given point.
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DESCRIPTION

17       T           (real, input) A real value to be mapped onto  the  interpo‐
18                   lating curve.  Values of T between zero and one interpolate
19                   the original data; any  values  of  T  outside  this  range
20                   result in extrapolation.
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22       N           (integer, input)  The number of points which were specified
23                   to determine the curve in CURVS1.
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25       PARAM       (real, input) The arc lengths as computed by CURVS1.
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27       X           (real, input) An array containing the  X-coordinate  values
28                   of the specified points.
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30       Y           (real,  input)  An array containing the Y-coordinate values
31                   of the specified points.
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33       XP          (real, input) An array of second derivative values as  cal‐
34                   culated by CURVS1.
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36       YP          (real,  input) An array of second derivative values as cal‐
37                   culated by CURVS1.
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39       SIGMA       (real, input) Tension factor. Values near zero result in  a
40                   cubic  spline;  large  values  (e.g. 50) result in nearly a
41                   polygonal line. A typical value is 1.
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43       XO          (real, output) The interpolated X value.
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45       YO          (real, output) The interpolated Y value.
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ACCESS

48       To use CURV2, load the NCAR Graphics library ngmath.
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SEE ALSO

51       curvs1, fitgrid_params.
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53       Complete documentation for Fitgrid is available at URL
54       http://ngwww.ucar.edu/ngdoc/ng/ngmath/fitgrid/fithome.html
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57       Copyright (C) 2000
58       University Corporation for Atmospheric Research
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60       This documentation is free software; you  can  redistribute  it  and/or
61       modify  it  under  the  terms of the GNU General Public License as pub‐
62       lished by the  Free  Software  Foundation;  either  version  2  of  the
63       License, or (at your option) any later version.
64
65       This  software  is  distributed in the hope that it will be useful, but
66       WITHOUT ANY  WARRANTY;  without  even  the  implied  warranty  of  MER‐
67       CHANTABILITY  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
68       Public License for more details.
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70       You should have received a copy of the GNU General Public License along
71       with  this  software;  if  not,  write to the Free Software Foundation,
72       Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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77UNIX                              August 2002                   CURVS2(3NCARG)
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