Package dev.nm.analysis.curvefit.interpolation

Class NevilleTable

java.lang.Object
dev.nm.analysis.function.rn2r1.AbstractRealScalarFunction
dev.nm.analysis.function.rn2r1.univariate.AbstractUnivariateRealFunction
dev.nm.analysis.curvefit.interpolation.NevilleTable
All Implemented Interfaces:
OnlineInterpolator, Function<Vector,Double>, RealScalarFunction, UnivariateRealFunction
public class NevilleTable extends AbstractUnivariateRealFunction implements OnlineInterpolator
Neville's algorithm is a polynomial interpolation algorithm. Given n + 1 points, there is a unique polynomial of degree ≤ n which associates with them. Neville's algorithm evaluates this polynomial for a given input x.

This implementation is based on filling out the Neville table. This table can be used in two ways. First, it can be used to compute the interpolated function f(x). Second, it can be used in an incremental manner by adding a few, say one, data points each time to allow for examination of the table values.

See Also:

  • Constructor Details

    • NevilleTable

      public NevilleTable(int n, OrderedPairs f)
      Construct a Neville table of size n, initialized with data {(x, y)}. The size n is only indicative. If there are more data points than n, the table size grows accordingly.
      Parameters:
      n - indicative size; make this big for reservation to add new data points
      f - the points to be interpolated

    • NevilleTable

      public NevilleTable(OrderedPairs f)
      Construct a Neville table of size n, initialized with data {(x, y)}.
      Parameters:
      f - the points to be interpolated

    • NevilleTable

      public NevilleTable()
      Construct an empty Neville table.

  • Method Details

    • addData

      public void addData(OrderedPairs f)
      Description copied from interface: OnlineInterpolator
      Add more points for interpolation.
      Specified by:
      addData in interface OnlineInterpolator
      Parameters:
      f - the points to be interpolated

    • N

      public int N()
      Get the number of data points.
      Returns:
      the number of data points

    • getTable

      public double[][] getTable()
      Get a copy of the Neville table.
      Returns:
      a copy of the table

    • x

      public double[] x()
      Get a copy of the x's.
      Returns:
      a copy of x's.

    • get

      public double get(int i, int j)
      Get the value of a table entry.
      Parameters:
      i - row index, counting from 0
      j - column index, counting from 0
      Returns:
      the value of the table entry

    • evaluate

      public double evaluate(double x)
      Description copied from interface: UnivariateRealFunction
      Evaluate y = f(x).
      Specified by:
      evaluate in interface UnivariateRealFunction
      Parameters:
      x - x
      Returns:
      f(x)