Hi Paul, This is what we use (given WGS84 coordinates) T3GeoTools class>>#distanceBetween: firstPosition and: secondPosition "T3GeoTools distanceBetween: 5.33732@50.926 and: 5.49705@50.82733" | c | c := (firstPosition y degreeSin * secondPosition y degreeSin) + (firstPosition y degreeCos * secondPosition y degreeCos * (secondPosition x degreesToRadians - firstPosition x degreesToRadians) cos). c := c >= 0 ifTrue: [ 1 min: c ] ifFalse: [ -1 max: c ]. ^ c arcCos * 6371000 Sven

On 05 Oct 2016, at 23:28, Paul DeBruicker <pdebruic@gmail.com> wrote:

umm ... here is a good place to start

http://forum.world.st/Geo-coordinates-operations-td4732373.html#a4732441

Paul DeBruicker wrote

...

I've got a few objects with latitude and longitude and want to be able to find the nearest from a collection

Thanks

Paul

-- View this message in context: http://forum.world.st/Is-there-any-library-to-calculate-the-geographic-dista... Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

On 06 Oct 2016, at 00:07, Hernán Morales Durand <hernan.morales@gmail.com> wrote:

Hi Sven,

Are you ok if I integrate your code into Territorial?

Sure ! BTW, I got the basic code from http://www.movable-type.co.uk/scripts/latlong.html with the necessary adaptions.

I'd like to have

'Ottawa@CA' asTerritoiralCity distanceWGS84To: 'Rome@IT' asTerritorialCity

Well, I also have this one that you might need (testing containment in a closed polygon). T3GeoTools class>>#is: position inside: polygon "T3GeoTools is: 5.33732@50.92601 inside: { 5.48230@50.82249. 5.49523@50.81288. 5.50138@50.82008. 5.50228@50.82595. 5.49265@50.82560. 5.48230@50.82249 }" "T3GeoTools is: 5.49007@50.82205 inside: { 5.48230@50.82249. 5.49523@50.81288. 5.50138@50.82008. 5.50228@50.82595. 5.49265@50.82560. 5.48230@50.82249 }" "Point in polygon - ray casting algorithm - http://www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html" | inside otherIndex | inside := false. otherIndex := polygon size. polygon doWithIndex: [ :each :index | | other | other := polygon at: otherIndex. (((each y > position y) ~= (other y > position y)) and: [ position x < (((other x - each x) * (position y - each y) / (other y - each y)) + each x) ]) ifTrue: [ inside := inside not ]. otherIndex := index ]. ^ inside Sven

Hernán

2016-10-05 19:00 GMT-03:00 Sven Van Caekenberghe <sven@stfx.eu>: Hi Paul,

This is what we use (given WGS84 coordinates)

T3GeoTools class>>#distanceBetween: firstPosition and: secondPosition "T3GeoTools distanceBetween: 5.33732@50.926 and: 5.49705@50.82733"

| c | c := (firstPosition y degreeSin * secondPosition y degreeSin) + (firstPosition y degreeCos * secondPosition y degreeCos * (secondPosition x degreesToRadians - firstPosition x degreesToRadians) cos). c := c >= 0 ifTrue: [ 1 min: c ] ifFalse: [ -1 max: c ]. ^ c arcCos * 6371000

Sven

...

On 05 Oct 2016, at 23:28, Paul DeBruicker <pdebruic@gmail.com> wrote:

umm ... here is a good place to start

http://forum.world.st/Geo-coordinates-operations-td4732373.html#a4732441

Paul DeBruicker wrote

...

I've got a few objects with latitude and longitude and want to be able to find the nearest from a collection

Thanks

Paul

-- View this message in context: http://forum.world.st/Is-there-any-library-to-calculate-the-geographic-dista... Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.