CODEWITHSUNDEEP
javascripttransformopenlayersopenlayers-3
Ben Clarke
Ben Clarke

Reputation: 1061

OpenLayers : 4326 ol.proj.transform not working

Issue

When I click on the map I want to transform the coordinates to format of 4326. When I do this it seems the Latitude part of the array transforms fine, but the Longitude part is incorrect and not valid.

Code

When I click on the Map, the SingleClick event fires, I then get the coordinates of where the user clicked:

Example of pPointClicked = [-40364190.03366159, 7054830.416117247];

session.Map.on('singleclick', function (e) {
    var pPointClicked = e.coordinate;
});

I try and transform these coordinates into 4326 by using the code below:

Example of coord4326 = [-362.59768838343064, 53.38659640004323];

session.Map.on('singleclick', function (e) {
    var pPointClicked = e.coordinate;

    var coord4326 = ol.proj.transform(pPointClicked, 'EPSG:3857', 'EPSG:4326');
});

As you can see the first value in the transformed variable is -362.59768838343064 which is incorrect? Does anyone know why this is happening.

Upvotes: 2

Views: 2032

Answers (1)

Alexandre Dubé
Alexandre Dubé

Reputation: 2829

The transformation seems to be working. Here's what I think is happening: you are not within the "original extent" of your map, i.e. you panned west and wrapped the entire world at least twice.

Try zooming out completely, then pan at the "same" location to the east twice, then click again. You should have the coordinate you're looking for.

Here's an other tip: the world extent, in EPSG:3857, is: 

[
  -20037508.342789244,
  -20037508.342789244,
  20037508.342789244,
  20037508.342789244
]

[-40364190.03366159, 7054830.416117247] is out of that extent, but if you pan to wrap the world twice, you should get: 289173.348083102, 7054830.416117247], which is within the extent.

Upvotes: 3

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