org.tinfour.utils

Class TinInstantiationUtility

java.lang.Object

org.tinfour.utils.TinInstantiationUtility

public class TinInstantiationUtility
extends Object

Provides a utility for instantiating either the QuadEdge or virtual versions of the TIN class based on the amount of memory available

Field Summary

Fields

Modifier and Type	Field and Description
static double	DEFAULT_MEMORY_FRACTION An arbitrary setting telling how much of the maximum memory to commit for processing the TIN.
static long	MEMORY_FOR_STANDARD Measured memory use by Hotspot JVM with a maximum memory setting smaller than 32 gigabytes, using object reference compression.
static long	MEMORY_FOR_VIRTUAL Measured memory use by Hotspot JVM with a maximum memory setting smaller than 32 gigabytes, using object reference compression.

Constructor Summary

Constructors

Constructor and Description
TinInstantiationUtility(double memoryUseFraction, int nVertices) Constructs an instance bases on a specification for how much memory is available for use and the anticipated number of vertices that will be added to the TIN.

Method Summary

Modifier and Type	Method and Description
IIncrementalTin	constructInstance(Class<?> tinClass, double nominalPointSpacing) Constructs an instance of the specified TIN class.
IIncrementalTin	constructInstance(double nominalPointSpacing) Uses the information about available memory use that was passed into the constructor to select a TIN class and construct and instance.
Class<?>	getTinClass() Get the class that was selected as most appropriate for the available memory and number of vertices.
void	printSummary(PrintStream ps) Prints a summary of the size computations and resulting IIncrementalTin class decision based on information supplied to the constructor.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_MEMORY_FRACTION

public static final double DEFAULT_MEMORY_FRACTION

An arbitrary setting telling how much of the maximum memory to commit for processing the TIN.

See Also:

Constant Field Values

MEMORY_FOR_VIRTUAL

public static final long MEMORY_FOR_VIRTUAL

Measured memory use by Hotspot JVM with a maximum memory setting smaller than 32 gigabytes, using object reference compression.

See Also:

Constant Field Values

MEMORY_FOR_STANDARD

public static final long MEMORY_FOR_STANDARD

Measured memory use by Hotspot JVM with a maximum memory setting smaller than 32 gigabytes, using object reference compression.

See Also:

Constant Field Values

Constructor Detail

TinInstantiationUtility

public TinInstantiationUtility(double memoryUseFraction,
                               int nVertices)

Constructs an instance bases on a specification for how much memory is available for use and the anticipated number of vertices that will be added to the TIN.

Parameters:

memoryUseFraction - the fraction of the JVM total memory that is allowed for memory use, a value in the range 0 to 1.

nVertices - the number of vertices to be used.

Method Detail

constructInstance

public IIncrementalTin constructInstance(Class<?> tinClass,
                                         double nominalPointSpacing)

Constructs an instance of the specified TIN class.

The nominal point spacing should be a rough estimate of the average distance between vertices. This value is used for establishing decision thresholds such as "when are two vertices so close together that they should be treated as one?" and does not need to be especially accurate. As long as it is within an order of magnitude of the true value, the Tinfour algorithms should produce good results.

Parameters:

tinClass - a valid class reference for an implementation of IIncrementalTin

nominalPointSpacing - a rough estimate of the average distance between vertices.

Returns:

a valid instance of the specified incremental TIN class.

constructInstance

public IIncrementalTin constructInstance(double nominalPointSpacing)

Uses the information about available memory use that was passed into the constructor to select a TIN class and construct and instance.

The nominal point spacing should be a rough estimate of the average distance between vertices. This value is used for establishing decision thresholds such as "when are two vertices so close together that they should be treated as one?" and does not need to be especially accurate. As long as it is within an order of magnitude of the true value, the Tinfour algorithms should produce good results.

Parameters:

nominalPointSpacing - a rough estimate of the average distance between vertices.

Returns:

a valid instance of a class that implements IIncrementalTin.

printSummary

public void printSummary(PrintStream ps)

Prints a summary of the size computations and resulting IIncrementalTin class decision based on information supplied to the constructor.

Parameters:

ps - the print stream.

getTinClass

public Class<?> getTinClass()

Get the class that was selected as most appropriate for the available memory and number of vertices.

Returns:

a valid class reference for an implementation of IIncrementalTin