org.geotools.grid

Class Grids

Object

Grids

public class Grids
extends Object

A utility class to create polygonal vector grids with basic attributes. For simple grids this is the only class you need. For finer control of grid attributes, such as working with a user-supplied SimpleFeatureType, see the Oblongs and Hexagons utility classes.

Since:

2.7

Author:

mbedward

Constructor Summary

Constructors

Constructor and Description
Grids()

Method Summary

Modifier and Type	Method and Description
static SimpleFeatureSource	createHexagonalGrid(ReferencedEnvelope bounds, double sideLen) Creates a vector grid of hexagonal elements.
static SimpleFeatureSource	createHexagonalGrid(ReferencedEnvelope bounds, double sideLen, double vertexSpacing) Creates a vector grid of hexagonal elements represented by 'densified' polygons.
static SimpleFeatureSource	createHexagonalGrid(ReferencedEnvelope bounds, double sideLen, double vertexSpacing, GridFeatureBuilder builder) Creates a vector grid of hexagonal elements represented by 'densified' polygons.
static SimpleFeatureSource	createSquareGrid(ReferencedEnvelope bounds, double sideLen) Creates a vector grid of square elements.
static SimpleFeatureSource	createSquareGrid(ReferencedEnvelope bounds, double sideLen, double vertexSpacing) Creates a vector grid of square elements represented by 'densified' polygons.
static SimpleFeatureSource	createSquareGrid(ReferencedEnvelope bounds, double sideLen, double vertexSpacing, GridFeatureBuilder builder) Creates a vector grid of square elements represented by 'densified' polygons.

Methods inherited from class Object

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

Constructor Detail

Grids

public Grids()

Method Detail

createSquareGrid

public static SimpleFeatureSource createSquareGrid(ReferencedEnvelope bounds,
                                                   double sideLen)

Creates a vector grid of square elements. The coordinate reference system is taken from the input bounds. A null coordinate reference system is permitted.

The grid's origin is the minimum X and Y point of the envelope. If the width and/or height of the bounding envelope is not a simple multiple of the requested side length, there will be some unfilled space.

Each square in the returned grid is represented by a SimpleFeature. The feature type has two properties:

• element - type Polygon
• id - type Integer

Parameters:

bounds - bounds of the grid

sideLen - the side length of grid elements

Returns:

the vector grid

Throws:

IllegalArgumentException - if bounds is null or empty; or if sideLen is <= 0

createSquareGrid

public static SimpleFeatureSource createSquareGrid(ReferencedEnvelope bounds,
                                                   double sideLen,
                                                   double vertexSpacing)

Creates a vector grid of square elements represented by 'densified' polygons. Each polygon has additional vertices added to its edges. This is useful if you plan to display the grid in a projection other than the one that it was created in since the extra vertices will better approximate curves. The density of vertices is controlled by the value of vertexSpacing which specifies the maximum distance between adjacent vertices. Vertices are added more or less uniformly.

The coordinate reference system is taken from the input bounds. A null coordinate reference system is permitted.

The grid's origin is the minimum X and Y point of the envelope. If the width and/or height of the bounding envelope is not a simple multiple of the requested side length, there will be some unfilled space.

Each square in the returned grid is represented by a SimpleFeature. The feature type has two properties:

• element - type Polygon
• id - type Integer

Parameters:

bounds - bounds of the grid

sideLen - the side length of grid elements

vertexSpacing - maximum distance between adjacent vertices in a grid element; if <= 0 or >= sideLen / 2.0 it is ignored and the polygons will not be densified

Returns:

the vector grid

Throws:

IllegalArgumentException - if bounds is null or empty; or if sideLen is <= 0

createSquareGrid

public static SimpleFeatureSource createSquareGrid(ReferencedEnvelope bounds,
                                                   double sideLen,
                                                   double vertexSpacing,
                                                   GridFeatureBuilder builder)

Creates a vector grid of square elements represented by 'densified' polygons. Each polygon has additional vertices added to its edges. This is useful if you plan to display the grid in a projection other than the one that it was created in since the extra vertices will better approximate curves. The density of vertices is controlled by the value of vertexSpacing which specifies the maximum distance between adjacent vertices. Vertices are added more or less uniformly.

The coordinate reference system is taken from the GridFeatureBuilder. A null coordinate reference system is permitted but if both the builder and bounding envelope have non-null reference systems set they must be the same.

The grid's origin is the minimum X and Y point of the envelope. If the width and/or height of the bounding envelope is not a simple multiple of the requested side length, there will be some unfilled space.

Parameters:

bounds - bounds of the grid

sideLen - the side length of grid elements

vertexSpacing - maximum distance between adjacent vertices in a grid element; if <= 0 or >= sideLen / 2.0 the polygons will not be densified

builder - the GridFeatureBuilder used to control feature creation and the setting of feature attribute values

Returns:

the vector grid

Throws:

IllegalArgumentException - if bounds is null or empty; or if sideLen is <= 0; or if builder is null; or if the CoordinateReferenceSystems set for the bounds and the GridFeatureBuilder are both non-null but different

createHexagonalGrid

public static SimpleFeatureSource createHexagonalGrid(ReferencedEnvelope bounds,
                                                      double sideLen)

Creates a vector grid of hexagonal elements. Hexagon size is expressed as side length. To create hexagons of specified area you can use the static Hexagons.areaToSideLength(double) method to calculate the equivalent side length.

The hexagons created by this method are orientated with a pair of edges parallel to the top and bottom of the bounding envelope (org.geotools.grid.hexagon.Hexagon.Orientation#FLAT). The bounding rectangle of each hexagon has width sideLen * 2.0 and height sideLen * sqrt(3.0).

The grid's origin is the minimum X and Y point of the envelope.

The feature type of grid features has two properties:

• element - type Polygon
• id - type Integer

Parameters:

bounds - bounds of the grid

sideLen - the length

Returns:

the vector grid

Throws:

IllegalArgumentException - if bounds is null or empty; or if sideLen is <= 0

createHexagonalGrid

public static SimpleFeatureSource createHexagonalGrid(ReferencedEnvelope bounds,
                                                      double sideLen,
                                                      double vertexSpacing)

Creates a vector grid of hexagonal elements represented by 'densified' polygons. Each polygon has additional vertices added to its edges. This is useful if you plan to display the grid in a projection other than the one that it was created in since the extra vertices will better approximate curves. The density of vertices is controlled by the value of vertexSpacing which specifies the maximum distance between adjacent vertices. Vertices are added more or less uniformly.

Hexagon size is expressed as side length. To create hexagons of specified area you can use the static Hexagons.areaToSideLength(double) method to calculate the equivalent side length.

The hexagons created by this method are orientated with a pair of edges parallel to the top and bottom of the bounding envelope (org.geotools.grid.hexagon.Hexagon.Orientation#FLAT). The bounding rectangle of each hexagon has width sideLen * 2.0 and height sideLen * sqrt(3.0).

The grid's origin is the minimum X and Y point of the envelope.

The feature type of grid features has two properties:

• element - type Polygon
• id - type Integer

Parameters:

bounds - bounds of the grid

sideLen - the length

vertexSpacing - maximum distance between adjacent vertices in a grid element; if <= 0 or >= sideLen / 2.0 the polygons will not be densified

Returns:

the vector grid

Throws:

IllegalArgumentException - if bounds is null or empty; or if sideLen is <= 0

createHexagonalGrid

public static SimpleFeatureSource createHexagonalGrid(ReferencedEnvelope bounds,
                                                      double sideLen,
                                                      double vertexSpacing,
                                                      GridFeatureBuilder builder)

Creates a vector grid of hexagonal elements represented by 'densified' polygons. Each polygon has additional vertices added to its edges. This is useful if you plan to display the grid in a projection other than the one that it was created in since the extra vertices will better approximate curves. The density of vertices is controlled by the value of vertexSpacing which specifies the maximum distance between adjacent vertices. Vertices are added more or less uniformly.

Hexagon size is expressed as side length. To create hexagons of specified area you can use the static Hexagons.areaToSideLength(double) method to calculate the equivalent side length.

The hexagons created by this method are orientated with a pair of edges parallel to the top and bottom of the bounding envelope (org.geotools.grid.hexagon.Hexagon.Orientation#FLAT). The bounding rectangle of each hexagon has width sideLen * 2.0 and height sideLen * sqrt(3.0).

The grid's origin is the minimum X and Y point of the envelope.

The feature type of grid features has two properties:

• element - type Polygon
• id - type Integer

Parameters:

bounds - bounds of the grid

sideLen - the length

vertexSpacing - maximum distance between adjacent vertices in a grid element; if <= 0 or >= sideLen / 2.0 the polygons will not be densified

builder - the GridFeatureBuilder used to control feature creation and the setting of feature attribute values

Returns:

the vector grid

Throws:

IllegalArgumentException - if bounds is null or empty; or if sideLen is <= 0; or if builder is null; or if the CoordinateReferenceSystems set for the bounds and the GridFeatureBuilder are both non-null but different