Package uk.co.mccombe.terrain

Class DEMReader

java.lang.Object
java.beans.PropertyChangeSupport
uk.co.mccombe.terrain.DEMReader
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
SRTM2Reader, SRTM3Reader
public abstract class DEMReader extends PropertyChangeSupport
DEMReader - an abstract base class for readers of various forms of Digital Elevation Model data sets
See Also:

  • Field Details

    • in

      protected static ZipInputStream in

    • DIRECTORY

      protected String DIRECTORY

    • cycle

      protected long cycle

    • cache

      protected HashMap<String,DEMReader.CacheEntry> cache

    • cacheEnable

      protected boolean cacheEnable

    • MAX_CACHE_SIZE

      protected static final int MAX_CACHE_SIZE
      See Also:

    • hits

      protected long hits

    • tries

      protected long tries

    • missing

      protected long missing

    • resultcount

      protected long resultcount

    • MISSING

      protected static final double MISSING
      See Also:

    • BUFFERLENGTH

      protected static final int BUFFERLENGTH
      See Also:

    • lastMessage

      protected String lastMessage

    • lastValue

      protected int lastValue

    • LOCALE

      protected static final Locale LOCALE

    • useLegacy

      protected boolean useLegacy

  • Constructor Details

  • Method Details

    • makename

      protected String makename(String ns, double lat, String ew, double lon)

    • getHeight

      public double getHeight(LatLong place) throws MissingDataFileException, DataFileException
      Calculate terrain height at a specified location using biaxial cubic Lagrangian interpolation on surrounding points in the tile. This method provides an exact fit at the points defined in the tile and a slightly smoothed surface in between. To speed the calculation up, rows of values from the tile are cached.
      Parameters:
      place - -- the LatLong of the place to calculate the height for.
      Returns:
      -- the calculated height at place.
      Throws:
      MissingDataFileException
      DataFileException

    • getRow

      protected DEMReader.CacheEntry getRow(String name, int ytile) throws MissingDataFileException, DataFileException
      Throws:
      MissingDataFileException
      DataFileException

    • readRecord

      public int[] readRecord() throws IOException
      Read the next record from the current ZipInputStream
      Returns:
      int[] buffer of length recordlength() containing the decoded next record;
      Throws:
      IOException

    • readByteRecord

      public byte[] readByteRecord() throws IOException
      Read the next byte record from the current ZipInputStream
      Returns:
      byte[] buffer of length recordlength() containing the decoded next record;
      Throws:
      IOException

    • tile

      public double tile(double x)
      Calculate the number of the element in the buffer that refers to a particular lat or lon value
      Parameters:
      x - the double lat/lon value
      Returns:
      A double value representing the buffer element index

    • frac

      public double frac(int tile)
      Calculate the proportion of a degree represented by a particular element in the buffer
      Parameters:
      tile - the integer number of the element
      Returns:
      double number representing a fraction of a degree

    • downloadFile

      protected void downloadFile(String filename) throws KeyManagementException, NoSuchAlgorithmException, IOException, MissingDataFileException, URISyntaxException
      Download a specific file and sand save it in scratch space on the local machine
      Parameters:
      filename - the name of the file to download
      Throws:
      KeyManagementException
      NoSuchAlgorithmException
      IOException
      MissingDataFileException
      URISyntaxException

    • lagrangian

      public static double lagrangian(double x, Point2D.Double... points)
      Fit an exact polynomial to a set of points and return its value at a specified point
      Parameters:
      x - double the value at which to evaluate the calculated polynomial
      points - a set of java.awt.geom.Point2D.Double values
      Returns:
      double value of the polynomial

    • hits

      public long hits()

    • resultcount

      public long resultcount()

    • tries

      public long tries()

    • missing

      public long missing()

    • resetCounts

      public void resetCounts()

    • setMessage

      protected void setMessage(String msg)

    • setProgress

      protected void setProgress(int val)

    • getProperty

      protected String getProperty(TerrainProperties propertyName)

    • getPropertyChangeListeners

      public PropertyChangeListener[] getPropertyChangeListeners()
      Overrides:
      getPropertyChangeListeners in class PropertyChangeSupport

    • datasetName

      public abstract String datasetName()

    • downloadable

      public abstract boolean downloadable()

    • recordlength

      public abstract int recordlength()

    • formatstring

      public abstract String formatstring()

    • extn

      public abstract String extn()

    • littleendian

      public abstract boolean littleendian()

    • missingValue

      public abstract int missingValue()

    • copyright

      public abstract String[] copyright()

    • setDownloadSiteName

      protected abstract void setDownloadSiteName(String s)

    • getDownloadSiteName

      protected abstract String getDownloadSiteName()

    • eastWest

      protected abstract String eastWest(double lon)

    • northSouth

      protected abstract String northSouth(double lat)

    • maxLat

      public abstract double maxLat()

    • minLat

      public abstract double minLat()

    • zipEntryName

      public String zipEntryName(String name)

    • numEntryName

      public String numEntryName(String name)