This rank-1 array function returns an array result, given an array of input. Use the optional argument for the covariance matrix when the square root of the variance function is required. The result will be a scalar value when the input variable is scalar.
Required Arguments
derivative
= derivative (Input)
The index of the derivative
evaluated. Use non-negative integer values. For the function itself
use the value 0.
variables
= variables (Input)
The independent variable values where the
spline or its derivatives are evaluated. Either a rank-1 array or a scalar
can be used as this argument.
knots
= knots (Input)
The derived type ?_spline_knots, defined as the array
COEFFS was
obtained with the function SPLINE_FITTING.
This contains the polynomial spline degree and the number of knots and the knots
themselves for this spline function.
coeffs
= c (Input)
The coefficients in the representation for the
spline function,
.
These
result from the fitting process or array assignment C=SPLINE_FITTING(...),
defined below. The value
N = size(C) satisfies the
identity
N - 1 + spline_degree = size (?_knots), where the two
right-most quantities refer to components of the argument knots.
Optional Arguments
covariance
= G (Input)
This argument, when present, results in the
evaluation of the square root of the variance function
where
and
is the covariance
matrix associated with the coefficients of the spline
The argument G is an optional output parameter from the function spline_fitting, described below. When the square root of the variance function is computed, the arguments DERIVATIVE and C are not used.
iopt
= iopt (Input)
This optional argument, of derived type ?_options, is not used in this
release.
FORTRAN 90 Interface
Generic: CALL SPLINE_VALUES (DERIVATIVE, VARAIBLES, KNOTS, COEFFS [,…])
Specific: The specific interface names are S_SPLINE_VALUES and D_SPLINE_VALUES.
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