plucky (3) curvd.3NCARG.gz

Provided by: libncarg-dev_6.6.2.dfsg.1-10build2_amd64 bug

NAME
       CURVD - derivatives for 1D functions.


SYNOPSIS
       FUNCTION CURVD (T, N, X, Y, YP, SIGMA)

       This  function  calculates a derivative at a specified point using a spline under tension.  CURV1 must be
       called prior to calling CURVD, and the values thus obtained used as input to CURVD. The derivative  value
       is returned.


DESCRIPTION
       T           (real, input) The abscissa for which an interpolated function value is desired.

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

       X           (real, input) An array containing the abscissae for the input function.

       Y           (real,  input)  An  array  containing  the functional values of the input data -- Y(K) is the
                   functional value at X(K) for K=1,N.

       YP          (real, input) Contains values for the second derivative (as calculated by CURV1).

       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.


RETURN VALUE
       CURVD returns the derivative value of the interpolated curve at the specified point T.


ACCESS
       To use CURVD, load the NCAR Graphics library ngmath.


SEE ALSO
       curv1, fitgrid_params.

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


       Copyright (C) 2000
       University Corporation for Atmospheric Research

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