X-Git-Url: http://gitweb.fperrin.net/?a=blobdiff_plain;f=tim%2Fprune%2Fdata%2FDataPoint.java;fp=tim%2Fprune%2Fdata%2FDataPoint.java;h=5d66ec55783a596d7bef1f1cd671dbe75a8c5b13;hb=312fec956e43f5d0a38617da5d0add9c62563e2c;hp=0000000000000000000000000000000000000000;hpb=db1c1602b89209f4c92e8bd12ad38cd243fb27c7;p=GpsPrune.git

diff --git a/tim/prune/data/DataPoint.java b/tim/prune/data/DataPoint.java
new file mode 100644
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--- /dev/null
+++ b/tim/prune/data/DataPoint.java
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+package tim.prune.data;
+
+/**
+ * Class to represent a single data point in the series
+ * including all its fields
+ * Can be either a track point or a waypoint
+ */
+public class DataPoint
+{
+	// Hold these as Strings?  Or FieldValue objects?
+	private String[] _fieldValues = null;
+	// list of fields
+	private FieldList _fieldList = null;
+	// Special fields for coordinates
+	private Coordinate _latitude = null, _longitude = null;
+	private Altitude _altitude;
+	private Timestamp _timestamp = null;
+	private boolean _pointValid = false;
+
+
+	// TODO: Make it possible to turn track point into waypoint - may need to alter FieldList
+
+	/**
+	 * Constructor
+	 * @param inValueArray array of String values
+	 * @param inFieldList list of fields
+	 * @param inAltFormat altitude format
+	 */
+	public DataPoint(String[] inValueArray, FieldList inFieldList, int inAltFormat)
+	{
+		// save data
+		_fieldValues = inValueArray;
+		// save list of fields
+		_fieldList = inFieldList;
+
+		// parse fields
+		_latitude = new Latitude(getFieldValue(Field.LATITUDE));
+		_longitude = new Longitude(getFieldValue(Field.LONGITUDE));
+		_altitude = new Altitude(getFieldValue(Field.ALTITUDE), inAltFormat);
+		_timestamp = new Timestamp(getFieldValue(Field.TIMESTAMP));
+	}
+
+
+	/**
+	 * Private constructor for artificially generated points (eg interpolated)
+	 * @param inLatitude latitude
+	 * @param inLongitude longitude
+	 * @param inAltitude altitude
+	 */
+	private DataPoint(Coordinate inLatitude, Coordinate inLongitude, Altitude inAltitude)
+	{
+		// Only these three fields are available
+		_fieldValues = new String[0];
+		_fieldList = new FieldList();
+		_latitude = inLatitude;
+		_longitude = inLongitude;
+		_altitude = inAltitude;
+		_timestamp = new Timestamp(null);
+	}
+
+
+	/**
+	 * Get the value for the given field
+	 * @param inField field to interrogate
+	 * @return value of field
+	 */
+	public String getFieldValue(Field inField)
+	{
+		return getFieldValue(_fieldList.getFieldIndex(inField));
+	}
+
+
+	/**
+	 * Get the value at the given index
+	 * @param inIndex index number starting at zero
+	 * @return field value, or null if not found
+	 */
+	public String getFieldValue(int inIndex)
+	{
+		if (_fieldValues == null || inIndex < 0 || inIndex >= _fieldValues.length)
+			return null;
+		return _fieldValues[inIndex];
+	}
+
+
+	public Coordinate getLatitude()
+	{
+		return _latitude;
+	}
+	public Coordinate getLongitude()
+	{
+		return _longitude;
+	}
+	public boolean hasAltitude()
+	{
+		return _altitude.isValid();
+	}
+	public Altitude getAltitude()
+	{
+		return _altitude;
+	}
+	public boolean hasTimestamp()
+	{
+		return _timestamp.isValid();
+	}
+	public Timestamp getTimestamp()
+	{
+		return _timestamp;
+	}
+
+	/**
+	 * @return true if point has a waypoint name
+	 */
+	public boolean isWaypoint()
+	{
+		String name = getFieldValue(Field.WAYPT_NAME);
+		return (name != null && !name.equals(""));
+	}
+
+	/**
+	 * Compare two DataPoint objects to see if they
+	 * are duplicates
+	 * @param inOther other object to compare
+	 * @return true if the points are equivalent
+	 */
+	public boolean isDuplicate(DataPoint inOther)
+	{
+		if (inOther == null) return false;
+		if (_longitude == null || _latitude == null
+			|| inOther._longitude == null || inOther._latitude == null)
+		{
+			return false;
+		}
+		// Compare latitude and longitude
+		if (!_longitude.equals(inOther._longitude) || !_latitude.equals(inOther._latitude))
+		{
+			return false;
+		}
+		// Note that conversion from decimal to dms can make non-identical points into duplicates
+		// Compare description (if any)
+		String name1 = getFieldValue(Field.WAYPT_NAME);
+		String name2 = inOther.getFieldValue(Field.WAYPT_NAME);
+		if (name1 == null || name1.equals(""))
+		{
+			return (name2 == null || name2.equals(""));
+		}
+		else
+		{
+			return (name2 != null && name2.equals(name1));
+		}
+	}
+
+
+	/**
+	 * @return true if the point is valid
+	 */
+	public boolean isValid()
+	{
+		return _latitude.isValid() && _longitude.isValid();
+	}
+
+
+	/**
+	 * Interpolate a set of points between this one and the given one
+	 * @param inEndPoint end point of interpolation
+	 * @param inNumPoints number of points to generate
+	 * @return the DataPoint array
+	 */
+	public DataPoint[] interpolate(DataPoint inEndPoint, int inNumPoints)
+	{
+		DataPoint[] range = new DataPoint[inNumPoints];
+		Coordinate endLatitude = inEndPoint.getLatitude();
+		Coordinate endLongitude = inEndPoint.getLongitude();
+		Altitude endAltitude = inEndPoint.getAltitude();
+
+		// Loop over points
+		for (int i=0; i<inNumPoints; i++)
+		{
+			Coordinate latitude = Coordinate.interpolate(_latitude, endLatitude, i, inNumPoints);
+			Coordinate longitude = Coordinate.interpolate(_longitude, endLongitude, i, inNumPoints);
+			Altitude altitude = Altitude.interpolate(_altitude, endAltitude, i, inNumPoints);
+			range[i] = new DataPoint(latitude, longitude, altitude);
+		}
+		return range;
+	}
+
+
+	/**
+	 * Calculate the number of radians between two points (for distance calculation)
+	 * @param inPoint1 first point
+	 * @param inPoint2 second point
+	 * @return angular distance between points in radians
+	 */
+	public static double calculateRadiansBetween(DataPoint inPoint1, DataPoint inPoint2)
+	{
+		if (inPoint1 == null || inPoint2 == null)
+			return 0.0;
+		final double TO_RADIANS = Math.PI / 180.0;
+		// Get lat and long from points
+		double lat1 = inPoint1.getLatitude().getDouble() * TO_RADIANS;
+		double lat2 = inPoint2.getLatitude().getDouble() * TO_RADIANS;
+		double lon1 = inPoint1.getLongitude().getDouble() * TO_RADIANS;
+		double lon2 = inPoint2.getLongitude().getDouble() * TO_RADIANS;
+		// Formula given by Wikipedia:Great-circle_distance as follows:
+		// angle = 2 arcsin( sqrt( (sin ((lat2-lat1)/2))^^2 + cos(lat1)cos(lat2)(sin((lon2-lon1)/2))^^2))
+		double firstSine = Math.sin((lat2-lat1) / 2.0);
+		double secondSine = Math.sin((lon2-lon1) / 2.0);
+		double term2 = Math.cos(lat1) * Math.cos(lat2) * secondSine * secondSine;
+		double answer = 2 * Math.asin(Math.sqrt(firstSine*firstSine + term2));
+		// phew
+		return answer;
+	}
+}