Package org.tinfour.utils

Class 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 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 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.

    • 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