1CURVPI(3NCARG) NCAR GRAPHICS CURVPI(3NCARG)
2
3
4
6 CURVPI - integrate a periodic spline curve
7
9 FUNCTION CURVPI (XL, XU, N, X, Y, P, YP, SIGMA)
10
11 This function calculates an integral between two specified limits.
12 CURVP1 must be called prior to calling CURVPI, and the values thus
13 obtained used as input to CURVPI. The value of the integral is
14 returned.
15
17 XL (real, input) The lower limit of the integration.
18
19 XR (real, input) The upper limit of the integration.
20
21 N (real, input) The number of input data values. (N > 1)
22
23 X (real, input) An array containing the abscissae for the
24 input function.
25
26 Y (real, input) An array containing the functional values of
27 the input function -- Y(K) is the (real, input) functional
28 value at X(K) for K=1,N.
29
30 P (real, input) The period of the function.
31
32 YP (real, input) Contains values for the second derivative (as
33 calculated by CURV1).
34
35 SIGMA (real, input) Tension factor. Values near zero result in a
36 cubic spline; large values (e.g. 50) result in nearly a
37 polygonal line. A typical value is 1.
38
40 CURVPI returns the integral of the interpolated curve between the spec‐
41 ified limits.
42
44 To use CURVPI, load the NCAR Graphics library ngmath.
45
47 curv1, fitgrid_params.
48
49 Complete documentation for Fitgrid is available at URL
50 http://ngwww.ucar.edu/ngdoc/ng/ngmath/fitgrid/fithome.html
51
53 Copyright (C) 2000
54 University Corporation for Atmospheric Research
55
56 The use of this Software is governed by a License Agreement.
57
58
59
60UNIX March 1998 CURVPI(3NCARG)