gov.sns.tools.math.r3
Class Grid

java.lang.Object
  |
  +--gov.sns.tools.math.r3.Grid

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

PoissonGrid

public class Grid

extends java.lang.Object

implements java.io.Serializable

Represents a regular grid in three dimensions. Grid resolution may vary in each dimension, however, no uneven mesh spacing is permitted. Consequently, operations on this grid are less general but faster.

See Also:

Serialized Form

Constructor Summary

Grid(int n1, int n2, int n3)
Allocate a new Grid

Grid(int n1, int n2, int n3, ClosedBox boxDom)
Allocate a new instance of GridR3 and set the domain.

Method Summary

protected gov.sns.tools.math.r3.Grid.GridCell[][][]	allocateCells(int n1, int n2, int n3) Allocates the array of grid cell objects.
protected gov.sns.tools.math.r3.Grid.GridPt[][][]	allocatePts(int n1, int n2, int n3) Allocates the array of grid point objects.
gov.sns.tools.math.r3.Grid.GridCell	compCellContaining(R3 pt) Return the grid cell containing this point.
Z3	compCellIndex(R3 pt) Compute the base vertex index of grid cell containing this point.
R3	compPtCoords(int i, int j, int k) Return the coordinates in R3 of the grid point at index (i,j,k)
R3	compPtCoords(Z3 vecIndex) Return the coordinates in R3 of the grid point at index (i,j,k)
protected gov.sns.tools.math.r3.Grid.GridCell	getGridCell(int i, int j, int k) Return the grid cell object located at grid point index.
protected gov.sns.tools.math.r3.Grid.GridCell	getGridCell(Z3 vecInd) Return the grid cell object located at grid cell index.
ClosedBox	getGridDomain() Get the domain of the grid in R3.
R3	getGridOrigin() Get the coordinates of the grid origin, i.e., the first grid vertex.
protected gov.sns.tools.math.r3.Grid.GridPt	getGridPt(int i, int j, int k) Return the grid point object located at grid point index.
protected gov.sns.tools.math.r3.Grid.GridPt	getGridPt(Z3 vecInd) Return the grid point object located at grid point index.
R3	getGridResolution() Get grid resolution.
Z3	getGridSize() Get the size of the supporting object array.
double	getPtValue(int i, int j, int k) Get the function value at the grid point indexed by (i,j,k)
R3	interpolateGradient(R3 pt) Compute and return the interpolated function gradient at the point pt.
double	interpolateValue(R3 pt) Compute and return the interpolated function value at the point pt
static void	main(java.lang.String[] args) Testing engine
boolean	membershipGrid(R3 pt) Determine whether a point is an element of the domain of definition for this grid.
void	print(java.io.PrintWriter os) Print out grid parameters on an output stream
void	setGridDomain(ClosedBox boxDom) Set the domain in R3 which the grid occupies.
void	setPtValue(int i, int j, int k, double dblVal) Set the function value at grid point given by index

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Grid

public Grid(int n1,
            int n2,
            int n3)
     throws GridException

Allocate a new Grid

Parameters:

n1 - number of grid points in first dimension

n2 - number of grid points in second dimension

n3 - number of grid points in third dimension

Throws:

GridException - unable to allocate grid objects

Grid

public Grid(int n1,
            int n2,
            int n3,
            ClosedBox boxDom)
     throws GridException

Allocate a new instance of GridR3 and set the domain.

Parameters:

n1 - number of grid points in first dimension

n2 - number of grid points in second dimension

n3 - number of grid points in third dimension

boxDom - descriptor of grid domain in R3

Throws:

GridException - invalid size vector encountered

Method Detail

setGridDomain

public void setGridDomain(ClosedBox boxDom)
                   throws GridException

Set the domain in R3 which the grid occupies. All grid point locations are determined by this descriptor.

Parameters:

boxDom - description of the grid position and size in R3

GridException

setPtValue

public void setPtValue(int i,
                       int j,
                       int k,
                       double dblVal)

Set the function value at grid point given by index

Parameters:

i - first dimension index of grid point

j - second dimension index of grid point

k - third dimension index of grid point

dblVal - value of the function at grid point (i,j,k)

getGridSize

public Z3 getGridSize()

Get the size of the supporting object array.

Returns:

vector of array dimensions (nx, ny, nz)

getGridDomain

public ClosedBox getGridDomain()

Get the domain of the grid in R3.

Returns:

a ClosedBox object describing the domain of definition for this grid

getGridResolution

public R3 getGridResolution()

Get grid resolution.

Returns:

vector (dx,dy,dz) of spacing between grid points

getGridOrigin

public R3 getGridOrigin()

Get the coordinates of the grid origin, i.e., the first grid vertex.

Returns:

(x,y,z) coordinates of grid origin

getPtValue

public double getPtValue(int i,
                         int j,
                         int k)

Get the function value at the grid point indexed by (i,j,k)

Parameters:

i - index of the first grid dimention

j - index of the second grid dimension

k - index of the third grid dimension

Returns:

function value stored at grid point (i,j,k)

membershipGrid

public boolean membershipGrid(R3 pt)

Determine whether a point is an element of the domain of definition for this grid.

Parameters:

pt - point in R3 to check membership

Returns:

true if pt is in domain of definition

compCellIndex

public Z3 compCellIndex(R3 pt)

Compute the base vertex index of grid cell containing this point. The base vertex is the vertex of the grid cell with smallest l1 norm. Grid cells are assigned by this index.

Parameters:

pt - pt in R3 (within the grid's domain of definition)

Returns:

index of grid cell owning pt

compPtCoords

public R3 compPtCoords(int i,
                       int j,
                       int k)

Return the coordinates in R3 of the grid point at index (i,j,k)

Parameters:

i - x-dimension index of grid point

j - y-dimension index of grid point

k - k-dimension index of grid point

Returns:

(x,y,z) coordinate of grid point at (i,j,k)

compPtCoords

public R3 compPtCoords(Z3 vecIndex)

Return the coordinates in R3 of the grid point at index (i,j,k)

Parameters:

vecIndex - (i,j,k) index vector of grid point

Returns:

(x,y,z) coordinate of grid point at (i,j,k)

compCellContaining

public gov.sns.tools.math.r3.Grid.GridCell compCellContaining(R3 pt)

Return the grid cell containing this point.

Parameters:

pt - pt in R3 (within the grid's domain of definition)

Returns:

grid cell object contain pt

interpolateValue

public double interpolateValue(R3 pt)

Compute and return the interpolated function value at the point pt

Parameters:

pt - interpolation point

Returns:

interpolated function value

interpolateGradient

public R3 interpolateGradient(R3 pt)

Compute and return the interpolated function gradient at the point pt. The gradient is taken with respect to the local coordinates of a grid cell. Thus, the true gradient must be scaled by the grid resolution and any other differential element particular to the coordinate system being used.

Parameters:

pt - interpolation point

Returns:

gradient (w.r.t. local cell coords) of function

print

public void print(java.io.PrintWriter os)

Print out grid parameters on an output stream

Parameters:

os - output stream to receive text description of grid

main

public static void main(java.lang.String[] args)

Testing engine

getGridPt

protected gov.sns.tools.math.r3.Grid.GridPt getGridPt(int i,
                                                      int j,
                                                      int k)

Return the grid point object located at grid point index.

Parameters:

i - 1st dimension grid point index

j - 2nd dimension grid point index

k - 3rd dimension grid point index

Returns:

object located at grid point (i,j,k)

getGridPt

protected gov.sns.tools.math.r3.Grid.GridPt getGridPt(Z3 vecInd)

Return the grid point object located at grid point index.

Parameters:

vecInd - vector index (i,j,k) of grid point

Returns:

object located at grid point (i,j,k)

getGridCell

protected gov.sns.tools.math.r3.Grid.GridCell getGridCell(int i,
                                                          int j,
                                                          int k)

Return the grid cell object located at grid point index.

Parameters:

i - 1st dimension grid cell index

j - 2nd dimension grid cell index

k - 3rd dimension grid cell index

Returns:

object located at grid cell (i,j,k)

getGridCell

protected gov.sns.tools.math.r3.Grid.GridCell getGridCell(Z3 vecInd)

Return the grid cell object located at grid cell index.

Parameters:

vecInd - vector index (i,j,k) of grid cell

Returns:

object located at grid cell (i,j,k)

allocatePts

protected gov.sns.tools.math.r3.Grid.GridPt[][][] allocatePts(int n1,
                                                              int n2,
                                                              int n3)
                                                       throws GridException

Allocates the array of grid point objects. Derived classes may create grid point objects derived from GridPt to perform specific tasks. Derived classes must override this method if the GridPt class also subclassed. The array of appropriate child class of GridPt should be returned.

Returns:

array of objects living at grid points

GridException

allocateCells

protected gov.sns.tools.math.r3.Grid.GridCell[][][] allocateCells(int n1,
                                                                  int n2,
                                                                  int n3)
                                                           throws GridException

Allocates the array of grid cell objects. Derived classes may create grid cell objects derived from GridCell to perform specific tasks. Derived classes must override this method if the GridCell class also subclassed. The array of appropriate child class of GridCell should be returned.

Returns:

array of objects composing grid cells

GridException