org.ka2ddo.aprs
Class NWSMultiLine

java.lang.Object
  org.ka2ddo.aprs.NWSMultiLine

All Implemented Interfaces:

java.io.Serializable

public class NWSMultiLine
extends java.lang.Object
implements java.io.Serializable

This class defines the lat/lon data within a NWS MultiLine encoded poly-figure. It can extract a MultiLine object from a PositionMessage's raw data.

The first two bytes are space and '}'. The next byte is a code for the type of data to plot:

NWS Multiline display codes

letter	color	line type	meaning
a	red	solid	tornado warning
b	red	dashed	tornado watch
c	red	double-dashed
d	yellow	solid	severe thunderstorm warning
e	yellow	dashed	severe thunderstorm watch
f	yellow	double-dashed
g	blue	solid	test warning
h	blue	dashed	test watch
i	blue	double-dashed
j	green	solid
k	green	dashed	mesoscale discussion area
l	green	double-dashed
m	orange	wide solid	Aloha circle for YAAC
n	orange	wide dashed	incomplete Aloha circle for YAAC

The next byte indicates the type of figure:

Figure type codes

character	meaning
0	closed polygon
1	line segment

The next byte indicates the scale value for the offsets relative to the record's position values.
Scale character (ascii value) = (integer(log to base 10 of the scale factor relative to .0001 degree) X 20 ) + 33

For more information, see http://www.aprs-is.net/WX/MultilineProtocol.aspx

Note that NWSMultiLine does not work for polygons and polylines spanning the International Date Line.

See Also:

Serialized Form

Field Summary

char	dataType The extracted data type for the MultiLine polygon.
int[]	lats Array of decoded latitudes in millionths of degrees North,
char	lineType Indicates whether closed polygon or open polyline.
int[]	lons Array of decoded longitudes in millionths of degrees East.
char	scale Scale factor character.

Constructor Summary

protected	NWSMultiLine()
	NWSMultiLine(double[] lats, double[] lons, boolean isClosed) Create an NWSMultiLine data structure from a set of latitude/lomgitude points.

Method Summary

static NWSMultiLine	extract(PositionMessage pm, byte[] body, int offset) Extract an NWSMultiLine from the specified position in a PositionMessage's comment.
ObjectReport	generateMessage(java.lang.String name, char symTableId, char symbolCode, java.lang.String freeText) Create an ObjectReport containing the encoding of this NWSMultiLine.
boolean	isClosed() Test whether this is a polyline or polygon.
java.lang.String	toString() Returns a string representation of the object.

Methods inherited from class java.lang.Object

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

Field Detail

dataType

public char dataType

The extracted data type for the MultiLine polygon.

lineType

public char lineType

Indicates whether closed polygon or open polyline.

scale

public char scale

Scale factor character.

lats

public int[] lats

Array of decoded latitudes in millionths of degrees North,

lons

public int[] lons

Array of decoded longitudes in millionths of degrees East.

Constructor Detail

NWSMultiLine

protected NWSMultiLine()

NWSMultiLine

public NWSMultiLine(double[] lats,
                    double[] lons,
                    boolean isClosed)

Create an NWSMultiLine data structure from a set of latitude/lomgitude points.

Parameters:

lats - array of latitudes in fractional degrees North

lons - array of longitudes in fractional degrees East

isClosed - boolean true if this is for a closed polygon, false for open polyline

Method Detail

extract

public static NWSMultiLine extract(PositionMessage pm,
                                   byte[] body,
                                   int offset)

Extract an NWSMultiLine from the specified position in a PositionMessage's comment.

Parameters:

pm - PositionMessage to extract reference latitude and longitude from

body - byte array of AX.25 message body

offset - starting position in body array where NWSMultiLine encoding begins

Returns:

decoded NWSMultiLine, or null if specified message position does not contain a NWSMultiLine

isClosed

public boolean isClosed()

Test whether this is a polyline or polygon.

Returns:

boolean true if a closed polygon

generateMessage

public ObjectReport generateMessage(java.lang.String name,
                                    char symTableId,
                                    char symbolCode,
                                    java.lang.String freeText)

Create an ObjectReport containing the encoding of this NWSMultiLine.

Parameters:

name - name to assign to the Object

symTableId - APRS symbol table ID (or overlay character) to associate with the Object

symbolCode - APRS symbol code to associated with the Object

freeText - free-text comment to append to the Object report

Returns:

constructed transmittable ObjectReport

toString

public java.lang.String toString()

Returns a string representation of the object.

Overrides:

toString in class java.lang.Object

Returns:

a string representation of the object.