org.cts.op.transformation.grids
Interface Grid

All Known Implementing Classes:

BleggGeographicGrid, GeographicGrid, IGNGeographicGrid, IGNVerticalGrid

public interface Grid

A grid is a data structure containing numeric data organized in rows and columns. Cell 0,0 represents a real location x0, y0, and every cell has a width (dx) and a height (dy) so that a cell at row i and column j represents a location of coordinates

• x = j*dx+x0
• y = i*dy+y0

The main grid parameters are :

• The number of columns (c) and rows (r) (with a total number of values in the grid equals to c * r)
• x0, y0, the real coordinates of the grid cell at column 0, row 0
• gridWidth and gridHeight, which represent the real grid width and the real grid height
Other derivative parameters are
• dx = gridWidth/(column number -1)
• dx = gridHeight/(row number -1)
For interpolation methods, see What's the point? Interpolation and extrapolation with a regular grid DEM

Author:

Michaël Michaud

Nested Class Summary

static class

Grid.InterpolationMethod

Field Summary

static int	BICUBIC Bicubic interpolation method.
static int	BILINEAR Bilinear interpolation method.
static int	NEAREST Nearest interpolation method.

Method Summary

int	getColumnNumber() Get the number of columns of this grid.
double	getDX() Real world interval between two consecutive columns.
double	getDY() Real world interval between two consecutive row.
int	getRowNumber() Get the number of rows of this grid.
double[]	getValue(double x, double y, Grid.InterpolationMethod method) Get the value corrsponding to the x,y position.
double	getX0() Get the real world abscisse (x) of the first column.
double	getXL() Get the first ordinate of the last grid column.
double	getY0() Get the real world ordinate (y) of the first row.
double	getYL() Get the second ordinate of the last grid row.

Field Detail

NEAREST

static final int NEAREST

Nearest interpolation method.

See Also:

Constant Field Values

BILINEAR

static final int BILINEAR

Bilinear interpolation method.

See Also:

Constant Field Values

BICUBIC

static final int BICUBIC

Bicubic interpolation method.

See Also:

Constant Field Values

Method Detail

getColumnNumber

int getColumnNumber()

Get the number of columns of this grid.

getRowNumber

int getRowNumber()

Get the number of rows of this grid.

getX0

double getX0()

Get the real world abscisse (x) of the first column.

getY0

double getY0()

Get the real world ordinate (y) of the first row.

getXL

double getXL()

Get the first ordinate of the last grid column.

getYL

double getYL()

Get the second ordinate of the last grid row.

getDX

double getDX()

Real world interval between two consecutive columns. The method returns a negative value if x values decreases when column indices increases.

getDY

double getDY()

Real world interval between two consecutive row. The method returns a negative value if y values decreases when column indices increases.

getValue

double[] getValue(double x,
                  double y,
                  Grid.InterpolationMethod method)
                  throws OutOfExtentException,
                         InterpolationMethodException

Get the value corrsponding to the x,y position. WARNING : x, y represent the real world coordinates and not the matrix coordinate.

Throws:

OutOfExtentException

InterpolationMethodException