au.com.objectix.jgridshift
Class SubGrid

java.lang.Object
  au.com.objectix.jgridshift.SubGrid

All Implemented Interfaces:

java.lang.Cloneable, java.io.Serializable

public class SubGrid

extends java.lang.Object

implements java.lang.Cloneable, java.io.Serializable

Models the NTv2 Sub Grid within a Grid Shift File

Author:

Peter Yuill

See Also:

Serialized Form

Constructor Summary

SubGrid(java.io.InputStream in, boolean bigEndian, boolean loadAccuracy)
Construct a Sub Grid from an InputStream, loading the node data into arrays in this object.

SubGrid(java.io.RandomAccessFile raf, long subGridOffset, boolean bigEndian)
Construct a Sub Grid from a RandomAccessFile.

Method Summary

java.lang.Object	clone() Make a deep clone of this Sub Grid
java.lang.String	getDetails()
double	getMaxLat()
double	getMaxLon()
double	getMinLat()
double	getMinLon()
int	getNodeCount()
java.lang.String	getParentSubGridName()
SubGrid	getSubGrid(int index)
int	getSubGridCount()
SubGrid	getSubGridForCoord(double lon, double lat) Tests if a specified coordinate is within this Sub Grid or one of its Sub Grids.
java.lang.String	getSubGridName()
GridShift	interpolateGridShift(GridShift gs) Interpolate shift and accuracy values for a coordinate in the 'from' datum of the GridShiftFile.
void	setSubGridArray(SubGrid[] subGrid) Set an array of Sub Grids of this sub grid
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

SubGrid

public SubGrid(java.io.InputStream in,
               boolean bigEndian,
               boolean loadAccuracy)
        throws java.io.IOException

Construct a Sub Grid from an InputStream, loading the node data into arrays in this object.

Parameters:

in - GridShiftFile InputStream

bigEndian - is the file bigEndian?

loadAccuracy - is the node Accuracy data to be loaded?

Throws:

java.lang.Exception

java.io.IOException

SubGrid

public SubGrid(java.io.RandomAccessFile raf,
               long subGridOffset,
               boolean bigEndian)
        throws java.io.IOException

Construct a Sub Grid from a RandomAccessFile. Only the headers are loaded into this object, the node data is accessed directly from the RandomAccessFile.

Parameters:

bigEndian - is the file bigEndian?

Throws:

java.lang.Exception

java.io.IOException

Method Detail

getSubGridForCoord

public SubGrid getSubGridForCoord(double lon,
                                  double lat)

Tests if a specified coordinate is within this Sub Grid or one of its Sub Grids. If the coordinate is outside this Sub Grid, null is returned. If the coordinate is within this Sub Grid, but not within any of its Sub Grids, this Sub Grid is returned. If the coordinate is within one of this Sub Grid's Sub Grids, the method is called recursively on the child Sub Grid.

Parameters:

lon - Longitude in Positive West Seconds

lat - Latitude in Seconds

Returns:

the Sub Grid containing the Coordinate or null

interpolateGridShift

public GridShift interpolateGridShift(GridShift gs)
                               throws java.io.IOException

Interpolate shift and accuracy values for a coordinate in the 'from' datum of the GridShiftFile. The algorithm is described in 'GDAit Software Architecture Manual' produced by the Geomatics Department of the University of Melbourne

This method is thread safe for both memory based and file based node data.

Parameters:

gs - GridShift object containing the coordinate to shift and the shift values

Returns:

the GridShift object supplied, with values updated.

Throws:

java.io.IOException

getParentSubGridName

public java.lang.String getParentSubGridName()

getSubGridName

public java.lang.String getSubGridName()

getNodeCount

public int getNodeCount()

getSubGridCount

public int getSubGridCount()

getSubGrid

public SubGrid getSubGrid(int index)

setSubGridArray

public void setSubGridArray(SubGrid[] subGrid)

Set an array of Sub Grids of this sub grid

Parameters:

subGrid -

toString

public java.lang.String toString()

getDetails

public java.lang.String getDetails()

clone

public java.lang.Object clone()

Make a deep clone of this Sub Grid

getMaxLat

public double getMaxLat()

Returns:

getMaxLon

public double getMaxLon()

Returns:

getMinLat

public double getMinLat()

Returns:

getMinLon

public double getMinLon()

Returns: