ncl_curvp2 man page

CURVP2 — interpolate a periodic function at a specified point

Synopsis

FUNCTION CURVP2 (T, N, X, Y, P, YP, SIGMA)

This function interpolates a value at a specified point using a spline under tension. CURVP1 must be called prior to calling CURVP2, and the values thus obtained used as input to CURVP2. CURVP2 returns the interpolated function value at the X-coordinate specified.

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.
X
(real, input) The period of the function.
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

CURVP2 returns the interpolated value at the specified point T.

Access

To use CURVP2, load the NCAR Graphics library ngmath.

See Also

curvp1, fitgrid_params.

Complete documentation for Fitgrid is available at URL
http://ngwww.ucar.edu/ngdoc/ng/ngmath/f…

Info

March 1998 UNIX NCAR GRAPHICS