com.ptvag.navigation.sdk

Enum CoordinateSystem

java.lang.Object

java.lang.Enum<CoordinateSystem>

com.ptvag.navigation.sdk.CoordinateSystem

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<CoordinateSystem>

public enum CoordinateSystem
extends java.lang.Enum<CoordinateSystem>

Enumeration of the coordinate formats used and supported by the NavigationSDK. The values can be used for coordinate transformations between different formats. The NavigationSDKs method MapView.transformCoordinates(CoordinateSystem, Position, CoordinateSystem) is the method to use for this purpose.

Geodez

The Geodez-format is nothing else than the well known WGS84 coordinate format. For further explanation of this format please consult WGS84.

Mercator

The PTV Mercator projection is a "Spherical Mercator" projection. This term is used by the GIS community to refer to the fact that Spherical Mercator uses the WGS 84 datum, but a Mercator projection which treats the earth as a sphere, rather than a projection which treats the earth as an ellipsoid. For more information about sperical mercator see Sperical Mercator. The PTV Mercator assumes an earth radius of 6371km. Therefore a simple method to convert from WGS84 and PTV Mercator would be:

 
 public static void LatLonToPtvMercator(double latitude, double longitude, out double x, out double y)
 {
     x = 6371000.0 * longitude * Math.PI / 180.0;
     y = 6371000.0 * Math.Log(Math.Tan(Math.PI / 4.0 + latitude * Math.PI / 360.0));
 }
 
 

PTV Mercator vs. Google Mercator
PTV and Google both use the same "Spherical Mercator" projection. Consult Google Maps deconstructed. The formula for calculating y from the latitude looks different, but it is the same because you can write log(tan(pi/4 + lat/2)) as 1/2log(1+sin(lat)/(1-sin(lat)). The only difference is the underlying earth radius. PTV (and ESRI SRID 53004) use 6371 km (the mean between major and minor axis of WGS 84), while Google, Microsoft, OSM and Yahoo use 6378137 meters (the major axis of WGS 84). Looking at the formula above, we see that the conversion between PTV and Google is quite simple.

 
 public static void PtvToGoogle(double ptvX, double ptvY, out double googleX, out double googleY)
 {
     googleX = (6378137.0 / 6371000.0) * ptvX;
     googleY = (6378137.0 / 6371000.0) * ptvY;
 }
 
 

Pixel

The Pixel coordinate format is defined as the number of pixels measured from the lower left corner of the screen.

Enum Constant Summary

Enum Constants

Enum Constant and Description
GEODEZ Geodecimal (value * 1000000) - WGS84
LATNMETER Latitude (X) and length in meter (Y)
MERCATOR PTV Mercator
PIXEL Pixel of rendered map (depends on the corresponding map view)

Method Summary

Modifier and Type	Method and Description
static CoordinateSystem	valueOf(java.lang.String name) Returns the enum constant of this type with the specified name.
static CoordinateSystem[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

MERCATOR

public static final CoordinateSystem MERCATOR

PTV Mercator

GEODEZ

public static final CoordinateSystem GEODEZ

Geodecimal (value * 1000000) - WGS84

PIXEL

public static final CoordinateSystem PIXEL

Pixel of rendered map (depends on the corresponding map view)

LATNMETER

public static final CoordinateSystem LATNMETER

Latitude (X) and length in meter (Y)

Method Detail

values

public static CoordinateSystem[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (CoordinateSystem c : CoordinateSystem.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static CoordinateSystem valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null