Package org.h2gis.functions.spatial.topology

Class ST_Graph

java.lang.Object

org.h2gis.api.AbstractFunction

org.h2gis.functions.spatial.topology.ST_Graph

All Implemented Interfaces:

org.h2gis.api.Function, org.h2gis.api.ScalarFunction

public class ST_Graph
extends org.h2gis.api.AbstractFunction
implements org.h2gis.api.ScalarFunction

Assigns integer node and edge ids to LINESTRING or MULTILINESTRING geometries from a table named input, resulting in two new tables: input_nodes and input_edges.

Author:

Adam Gouge, Erwan Bocher

Field Summary

Fields

Modifier and Type	Field	Description
static final String	ALREADY_RUN_ERROR
static String	COORDS_TABLE
static final String	EDGES_SUFFIX
static final String	NODES_SUFFIX
static String	PTS_TABLE
static final String	REMARKS
static final String	TYPE_ERROR

Fields inherited from interface org.h2gis.api.Function

PROP_NAME, PROP_REMARKS

Fields inherited from interface org.h2gis.api.ScalarFunction

PROP_DETERMINISTIC

Constructor Summary

Constructors

Constructor	Description
ST_Graph()	Constructor

Method Summary

Modifier and Type	Method	Description
static boolean	createGraph(Connection connection, String tableName)	Create the nodes and edges tables from the input table containing LINESTRINGs.
static boolean	createGraph(Connection connection, String tableName, String spatialFieldName)	Create the nodes and edges tables from the input table containing LINESTRINGs in the given column.
static boolean	createGraph(Connection connection, String tableName, String spatialFieldName, double tolerance)	Create the nodes and edges tables from the input table containing LINESTRINGs in the given column and using the given tolerance.
static boolean	createGraph(Connection connection, String inputTable, String spatialFieldName, double tolerance, boolean orientBySlope)	Create the nodes and edges tables from the input table containing LINESTRINGs in the given column and using the given tolerance, and potentially orienting edges by slope.
static boolean	createGraph(Connection connection, String inputTable, String spatialFieldName, double tolerance, boolean orientBySlope, boolean deleteTables)	Create the nodes and edges tables from the input table containing LINESTRINGs in the given column and using the given tolerance, and potentially orienting edges by slope.
String	getJavaStaticMethod()

Methods inherited from class org.h2gis.api.AbstractFunction

addProperty, getProperty, removeProperty

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.h2gis.api.Function

getProperty

Field Details

NODES_SUFFIX

public static final String NODES_SUFFIX

See Also:

• Constant Field Values

EDGES_SUFFIX

public static final String EDGES_SUFFIX

See Also:

• Constant Field Values

PTS_TABLE

public static String PTS_TABLE

COORDS_TABLE

public static String COORDS_TABLE

REMARKS

public static final String REMARKS

See Also:

• Constant Field Values

TYPE_ERROR

public static final String TYPE_ERROR

See Also:

• Constant Field Values

ALREADY_RUN_ERROR

public static final String ALREADY_RUN_ERROR

See Also:

• Constant Field Values

Constructor Details

ST_Graph

public ST_Graph()

Constructor

Method Details

getJavaStaticMethod

public String getJavaStaticMethod()

Specified by:

getJavaStaticMethod in interface org.h2gis.api.ScalarFunction

createGraph

public static boolean createGraph(Connection connection,
 String tableName)
                           throws SQLException

Create the nodes and edges tables from the input table containing LINESTRINGs. Since no column is specified in this signature, we take the first geometry column we find. If the input table has name 'input', then the output tables are named 'input_nodes' and 'input_edges'.

Parameters:

connection - Connection

tableName - Input table containing LINESTRINGs

Returns:

true if both output tables were created

Throws:

SQLException

createGraph

public static boolean createGraph(Connection connection,
 String tableName,
 String spatialFieldName)
                           throws SQLException

Create the nodes and edges tables from the input table containing LINESTRINGs in the given column. If the input table has name 'input', then the output tables are named 'input_nodes' and 'input_edges'.

Parameters:

connection - Connection

tableName - Input table

spatialFieldName - Name of column containing LINESTRINGs

Returns:

true if both output tables were created

Throws:

SQLException

createGraph

public static boolean createGraph(Connection connection,
 String tableName,
 String spatialFieldName,
 double tolerance)
                           throws SQLException

Create the nodes and edges tables from the input table containing LINESTRINGs in the given column and using the given tolerance. The tolerance value is used specify the side length of a square Envelope around each node used to snap together other nodes within the same Envelope. Note, however, that edge geometries are left untouched. Note also that coordinates within a given tolerance of each other are not necessarily snapped together. Only the first and last coordinates of a geometry are considered to be potential nodes, and only nodes within a given tolerance of each other are snapped together. The tolerance works only in metric units. If the input table has name 'input', then the output tables are named 'input_nodes' and 'input_edges'.

Parameters:

connection - Connection

tableName - Input table

spatialFieldName - Name of column containing LINESTRINGs

tolerance - Tolerance

Returns:

true if both output tables were created

Throws:

SQLException

createGraph

public static boolean createGraph(Connection connection,
 String inputTable,
 String spatialFieldName,
 double tolerance,
 boolean orientBySlope)
                           throws SQLException

Create the nodes and edges tables from the input table containing LINESTRINGs in the given column and using the given tolerance, and potentially orienting edges by slope. The tolerance value is used specify the side length of a square Envelope around each node used to snap together other nodes within the same Envelope. Note, however, that edge geometries are left untouched. Note also that coordinates within a given tolerance of each other are not necessarily snapped together. Only the first and last coordinates of a geometry are considered to be potential nodes, and only nodes within a given tolerance of each other are snapped together. The tolerance works only in metric units. The boolean orientBySlope is set to true if edges should be oriented by the z-value of their first and last coordinates (decreasing). If the input table has name 'input', then the output tables are named 'input_nodes' and 'input_edges'.

Parameters:

connection - Connection

inputTable - Input table

spatialFieldName - Name of column containing LINESTRINGs

tolerance - Tolerance

orientBySlope - True if edges should be oriented by the z-value of their first and last coordinates (decreasing)

Returns:

true if both output tables were created

Throws:

SQLException

createGraph

public static boolean createGraph(Connection connection,
 String inputTable,
 String spatialFieldName,
 double tolerance,
 boolean orientBySlope,
 boolean deleteTables)
                           throws SQLException

Create the nodes and edges tables from the input table containing LINESTRINGs in the given column and using the given tolerance, and potentially orienting edges by slope. The tolerance value is used specify the side length of a square Envelope around each node used to snap together other nodes within the same Envelope. Note, however, that edge geometries are left untouched. Note also that coordinates within a given tolerance of each other are not necessarily snapped together. Only the first and last coordinates of a geometry are considered to be potential nodes, and only nodes within a given tolerance of each other are snapped together. The tolerance works only in metric units. The boolean orientBySlope is set to true if edges should be oriented by the z-value of their first and last coordinates (decreasing). If the input table has name 'input', then the output tables are named 'input_nodes' and 'input_edges'.

Parameters:

connection - Connection

inputTable - Input table

spatialFieldName - Name of column containing LINESTRINGs

tolerance - Tolerance

orientBySlope - True if edges should be oriented by the z-value of their first and last coordinates (decreasing)

deleteTables - True delete the existing tables

Returns:

true if both output tables were created

Throws:

SQLException