hammad-raza / simplelatlng Goto Github PK

GeoConfig - doubleToLong: long cast will always floor the result leading to 
potentially unbounded cumulative errors.

Suggestion: use Math.round() instead

I'd like to see the addition of calculation of initial bearing from one LatLng 
to another. I need this along with distance and calculated it using the 
forumula given here http://williams.best.vwh.net/avform.htm and (in Javascript) 
here http://www.movable-type.co.uk/scripts/latlong.html.

I'm not sure it's worth the trouble, but there could be some optimization when 
calculating both distance and initial bearing since both calculations need some 
of the same intermediate values (including at least the radian-converted 
latitudes of each LatLng and the cosines of each of those values).

If you'd be interested in having this in the library I may be able to 
contribute a patch.

The LatLng.hashCode() use formatting, string concatenation and 
String.hashCode() to produce hash code for LatLng with good distribution.

However, this is slow and takes time even when there is no changes to the 
LatLng value.

A simple way to improve it is by caching the hash code instead of 
recalculation, similar to the way String.hashCode() works.

See this as a suggested solution: 
https://code.google.com/r/hagaishatz-fasthash/source/browse/src/main/java/com/ja
vadocmd/simplelatlng/LatLng.java

Thanks.

The following JUnit fails :
Locale.setDefault(Locale.FRANCE);
assertEquals("(6.123456,45.123456)", new  LatLng(6.123456, 
45.123456).toString());

The decimal separator is localized to ','
The result is then "(6,123456,45,123456)" which is confusing.

I would suggest the following fixe on LatLngConfig:34
public static final NumberFormat DEGREE_FORMAT = new DecimalFormat(
            "0.000000", new DecimalFormatSymbols(Locale.US)); 
instead of :
public static final NumberFormat DEGREE_FORMAT = new DecimalFormat(
            "0.000000"); 

BTW: DecimalFormat.format is not thread safe, you may consider creating a new 
DecimalFormat object on each format use. 

Any chanse this will be merged with http://github.com/kungfoo/geohash-java?

The following JUnit fails :
assertEquals(new LatLng(44.869797, 6.599944), 
Geohasher.decode(Geohasher.hash(new LatLng(44.869797, 6.599944))));

I was assuming that Geohasher.decode(Geohasher.hash(X))) equals X. Is that true 
? 
The geohash precision is the default 12 characters. 
simplelatlng-1.1.0.

It may be a rounding issue, as the computed latitude from geohash decode, 
before new Latlng(x, y) is  44.869,796,94105685 and expected result is 
44.869,797. see Geohash.decode:83.

Best regards,
-Leo

Currently the class LatLng doesn't implement Serializable although with only 
two long field to it there is not reason why it shouldn't.
All it need is a simple "implements java.io.Serializable"

It would be helpful in several ways, especially for persistence purposes as in 
my case, tomcat session and session attribute persistence between server 
restarts. Non serializable session attributes cannot be handled and throw a 
java.io.NotSerializableException.


Would it be possible to include this in a minor release, like 1.0.1?

Cheers, Andy

What steps will reproduce the problem?
Say I am using CircularWindow.filter()/filterCopy() to get the filtered points. 
I would like to have these points in sorted order close to the actual 
CircularWindow object. Currently the filter returns the CircularWindow 
containing points in the same order as the Collection passed in filter(). I 
have to recheck the distance for each of these points to the actual 
CircularWindow point and reorder. This affects the performance if I have many 
records.

What is the expected output? What do you see instead?
I would like to have the filtered collection is a sorted order of the distance 
along with the distance value(may be a new method in LatLng class, that can 
return the distance).

What version of the product are you using? On what operating system?
1.1.0, WinXP and Linux

Please provide any additional information below :
I'm not sure it's worth the trouble.

Given a point A, find the point B that is a distance C and a direction D from 
A. 

Any chance to see this lib in some maven repo?