cern.colt.matrix.doublealgo
Class Stencil

java.lang.Object
  cern.colt.matrix.doublealgo.Stencil

public class Stencil

extends Object

Stencil operations. For efficient finite difference operations. Applies a function to a moving 3 x 3 or 3 x 3 x 3 window. Build on top of matrix.zAssignXXXNeighbors(...). You can specify how many iterations shall at most be done, a convergence condition when iteration shall be terminated, and how many iterations shall pass between convergence checks. Always does two iterations at a time for efficiency. These class is for convencience and efficiency.

Version:

1.0, 01/02/2000

stencil27

public static int stencil27(DoubleMatrix3D A,
                            Double27Function function,
                            int maxIterations,
                            DoubleMatrix3DProcedure hasConverged,
                            int convergenceIterations)

27 point stencil operation. Applies a function to a moving 3 x 3 x 3 window.

Parameters:

A - the matrix to operate on.

function - the function to be applied to each window.

maxIterations - the maximum number of times the stencil shall be applied to the matrix. Should be a multiple of 2 because two iterations are always done in one atomic step.

hasConverged - Convergence condition; will return before maxIterations are done when hasConverged.apply(A)==true. Set this parameter to null to indicate that no convergence checks shall be made.

convergenceIterations - the number of iterations to pass between each convergence check. (Since a convergence may be expensive, you may want to do it only every 2,4 or 8 iterations.)

Returns:

the number of iterations actually executed.

stencil9

public static int stencil9(DoubleMatrix2D A,
                           Double9Function function,
                           int maxIterations,
                           DoubleMatrix2DProcedure hasConverged,
                           int convergenceIterations)

9 point stencil operation. Applies a function to a moving 3 x 3 window.

Parameters:

A - the matrix to operate on.

function - the function to be applied to each window.

maxIterations - the maximum number of times the stencil shall be applied to the matrix. Should be a multiple of 2 because two iterations are always done in one atomic step.

hasConverged - Convergence condition; will return before maxIterations are done when hasConverged.apply(A)==true. Set this parameter to null to indicate that no convergence checks shall be made.

convergenceIterations - the number of iterations to pass between each convergence check. (Since a convergence may be expensive, you may want to do it only every 2,4 or 8 iterations.)

Returns:

the number of iterations actually executed.