CALL CURVP1 (N, X, Y, P, YP, TEMP, SIGMA, IER)
This subroutine calculates certain values that are used by CURVP2 in order to compute an interpolatory spline under tension through a sequence of functional values for a periodic function. The actual computation of the interpolated values must be done using CURVP2 .
(integer, input) The number of input data values. (N > 1)
(real, input) An array containing the abscissae for the input function.
(real, input) An array containing the functional values of the input function -- Y(K) is the functional value at X(K) for K=1,N.
(real, input) The period of the function. P must be greater than X(N)-X(1).
(real, output) Contains values for the second derivative (these are calculated by CURVP1).
(real, input) Scratch space.
(integer, 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.
(integer, output) An error return value. If IER is returned as 0, then no errors were detected.
= 1 if N is less than 2.
= 2 if P is less than or equal to X(N)-X(1).
= 3 if the X values are not strictly increasing.
To use CURVP1, load the NCAR Graphics library ngmath.
Complete documentation for Fitgrid is available at URL
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University Corporation for Atmospheric Research
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