public class BicubicInterpolatingFunction extends java.lang.Object implements BivariateFunction
Modifier and Type | Field and Description |
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private static double[][] |
AINV
Matrix to compute the spline coefficients from the function values
and function derivatives values
|
private static int |
NUM_COEFF
Number of coefficients.
|
private BicubicFunction[][] |
splines
Set of cubic splines patching the whole data grid
|
private double[] |
xval
Samples x-coordinates
|
private double[] |
yval
Samples y-coordinates
|
Constructor and Description |
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BicubicInterpolatingFunction(double[] x,
double[] y,
double[][] f,
double[][] dFdX,
double[][] dFdY,
double[][] d2FdXdY) |
Modifier and Type | Method and Description |
---|---|
private double[] |
computeSplineCoefficients(double[] beta)
Compute the spline coefficients from the list of function values and
function partial derivatives values at the four corners of a grid
element.
|
boolean |
isValidPoint(double x,
double y)
Indicates whether a point is within the interpolation range.
|
private int |
searchIndex(double c,
double[] val) |
double |
value(double x,
double y)
Compute the value for the function.
|
private static final int NUM_COEFF
private static final double[][] AINV
private final double[] xval
private final double[] yval
private final BicubicFunction[][] splines
public BicubicInterpolatingFunction(double[] x, double[] y, double[][] f, double[][] dFdX, double[][] dFdY, double[][] d2FdXdY) throws DimensionMismatchException, NoDataException, NonMonotonicSequenceException
x
- Sample values of the x-coordinate, in increasing order.y
- Sample values of the y-coordinate, in increasing order.f
- Values of the function on every grid point.dFdX
- Values of the partial derivative of function with respect
to x on every grid point.dFdY
- Values of the partial derivative of function with respect
to y on every grid point.d2FdXdY
- Values of the cross partial derivative of function on
every grid point.DimensionMismatchException
- if the various arrays do not contain
the expected number of elements.NonMonotonicSequenceException
- if x
or y
are
not strictly increasing.NoDataException
- if any of the arrays has zero length.public double value(double x, double y) throws OutOfRangeException
value
in interface BivariateFunction
x
- Abscissa for which the function value should be computed.y
- Ordinate for which the function value should be computed.OutOfRangeException
public boolean isValidPoint(double x, double y)
x
- First coordinate.y
- Second coordinate.true
if (x, y) is a valid point.private int searchIndex(double c, double[] val)
c
- Coordinate.val
- Coordinate samples.val
corresponding to the interval
containing c
.OutOfRangeException
- if c
is out of the
range defined by the boundary values of val
.private double[] computeSplineCoefficients(double[] beta)
beta
- List of function values and function partial derivatives
values.