Re: [android-developers] Re: How to calculate the distance between two degree values? (for example: 350º to 15º = 25º / 250º to 190º = 60º)
But if you mean distance in degrees it would be 'x mod 360' Op 29 sep. 2011 17:42 schreef "JackN" het volgende: -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: How to calculate the distance between two degree values? (for example: 350º to 15º = 25º / 250º to 190º = 60º)
If you already have the two numbers in degress that are between 0 and 360... int iDiff = Math.abs( degree1 - degree2 ); If you need to find them from points or latitude/longitude, then you are entering into linear math and you would need to look at things like: http://chortle.ccsu.edu/VectorLessons/vectorIndex.html Steven Studio LFP http://www.studio-lfp.com -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: How to calculate the distance between two degree values? (for example: 350º to 15º = 25º / 250º to 190º = 60º)
I would like to reiterate what JackN said -- you don't have enough
info. But a good place to start would here:
http://www.movable-type.co.uk/scripts/latlong.html
For those interested, a routine for the distance between two points
(on Earth) in kilometers is:
public double gps2m(double lat_a, double lng_a, double lat_b, double
lng_b) {
double R = 6371;//km
double dLat = (lat_b - lat_a) * (Math.PI / 180.0);
double dLon = (lng_b - lng_a) * (Math.PI / 180.0);
double a = Math.sin(dLat/2) * Math.sin(dLat/2) + Math.cos(lat_a *
(Math.PI / 180.0))
* Math.cos(lat_b * (Math.PI / 180.0)) * Math.sin(dLon/2) *
Math.sin(dLon/2);
double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
return R * c;
}
where lat_a and lng_a are your start coordinates and lat_b and lng_b
are your stop coordinates.
Ken H
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[android-developers] Re: How to calculate the distance between two degree values? (for example: 350º to 15º = 25º / 250º to 190º = 60º)
Distance is the space between two points. You don't have enough info to calculate the distance. On Sep 27, 9:58 am, Lew Bloch wrote: > On Tuesday, September 27, 2011 7:29:09 AM UTC-7, saex wrote: > > > there is a function or something on Java to calculate the distance > > between two degree values? (min 0º and max 360º) > > > for example: > > > 350º to 15º = 25º > > > 250º to 190º = 60º > > Which way do you want it? They cannot both be correct. > > Bearing is conventionally calculated positive-clockwise with 0° at North (or > "face forward" for relative bearing), most maths work > positive-counterclockwise with 0° corresponding to the positive x axis. > > Either way, 350° to 15° is +25° or -335°, and 250° to 190° is -60° or +300°, > depending on how you want to play it. > > You can use the remainder operator or manually add or subtract 360° to make > things fall into your desired target range. Your basic operation is > subtraction modulo 360. A conventional range is [-180°, 180°). > > etc... > > "Etc." takes a single period to end the abbreviation. The term "etc." only > makes sense once you have established a consistent pattern, which your post > did not. > > -- > Lew -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: How to calculate the distance between two degree values? (for example: 350º to 15º = 25º / 250º to 190º = 60º)
On Tuesday, September 27, 2011 7:29:09 AM UTC-7, saex wrote: > > there is a function or something on Java to calculate the distance > between two degree values? (min 0º and max 360º) > > for example: > > 350º to 15º = 25º > > 250º to 190º = 60º > > Which way do you want it? They cannot both be correct. Bearing is conventionally calculated positive-clockwise with 0° at North (or "face forward" for relative bearing), most maths work positive-counterclockwise with 0° corresponding to the positive x axis. Either way, 350° to 15° is +25° or -335°, and 250° to 190° is -60° or +300°, depending on how you want to play it. You can use the remainder operator or manually add or subtract 360° to make things fall into your desired target range. Your basic operation is subtraction modulo 360. A conventional range is [-180°, 180°). etc... > > "Etc." takes a single period to end the abbreviation. The term "etc." only makes sense once you have established a consistent pattern, which your post did not. -- Lew -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
[android-developers] Re: How to calculate the distance between two degree values? (for example: 350º to 15º = 25º / 250º to 190º = 60º)
This is not an android question, nor is it even a java question. But I can try to help anyway. You would probably get more help in a general purpose programming forum such as codeguru. Anyway, you didn't give enough information. Do you always want to go clockwise or counter-clockwise from the start degree to the finish degree. Or do you want the shortest path, no matter what direction? -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
