Spline2DInterpolate Class |
Namespace: Imsl.Math
The Spline2DInterpolate type exposes the following members.
Name | Description | |
---|---|---|
Spline2DInterpolate(Double, Double, Double) | Constructor for Spline2DInterpolate.
| |
Spline2DInterpolate(Double, Double, Double, Int32, Int32) | Constructor for Spline2DInterpolate.
| |
Spline2DInterpolate(Double, Double, Double, Int32, Int32, Double, Double) | Constructor for Spline2DInterpolate.
|
Name | Description | |
---|---|---|
Derivative(Double, Double, Int32, Int32) | Returns the value of the partial derivative of the tensor-product spline
at the point (x, y).
(Inherited from Spline2D.) | |
Derivative(Double, Double, Int32, Int32) | Returns the values of the partial derivative of the tensor-product spline
of an array of points.
(Inherited from Spline2D.) | |
Equals | Determines whether the specified object is equal to the current object. (Inherited from Object.) | |
Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) | |
GetCoefficients | Returns the coefficients for the tensor-product spline.
(Inherited from Spline2D.) | |
GetHashCode | Serves as a hash function for a particular type. (Inherited from Object.) | |
GetType | Gets the Type of the current instance. (Inherited from Object.) | |
GetXKnots |
Returns the knot sequences in the x-direction.
(Inherited from Spline2D.) | |
GetYKnots | Returns the knot sequences in the y-direction.
(Inherited from Spline2D.) | |
Integral | Returns the value of an integral of a tensor-product spline
on a rectangular domain. (Inherited from Spline2D.) | |
MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) | |
ToString | Returns a string that represents the current object. (Inherited from Object.) | |
Value(Double, Double) | Returns the value of the tensor-product spline at the point (x, y).
(Inherited from Spline2D.) | |
Value(Double, Double) | Returns the values of the tensor-product spline of an array of points.
(Inherited from Spline2D.) |
The class Spline2DInterpolate computes a tensor-product spline interpolant. The tensor-product spline interpolant to data , where and has the form
where and are the orders of the splines. These numbers are defaulted to be 4, but can be set to any positive integer using xOrder and yOrder in the constructor. Likewise, and are the corresponding knot sequences (xKnots and yKnots). These default values are selected by Spline2DInterpolate. The algorithm requires that Tensor-product spline interpolants in two dimensions can be computed quite efficiently by solving (repeatedly) two univariate interpolation problems.The computation is motivated by the following observations. It is necessary to solve the system of equations
Setting note that for each fixed i from 0 to , we have linear equations in the same number of unknowns as can be seen below: Setting note that for each fixed i from 0 to , we have linear equations in the same number of unknowns as can be seen below: The same matrix appears in all of the equations above: Thus, only factor this matrix once and then apply this factorization to the right-hand sides. Once this is done and is computed, then solve for the coefficients using the relation for n from 0 to , which again involves one factorization and solutions to the different right-hand sides. The class Spline2DInterpolate is based on the routine SPLI2D by de Boor (1978, p. 347).