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I'm trying to figure out how to calculate the lat/long of points using the QGIS Field Calculator.
Is there an easy way to do this?
I saw a previous related question (Using QGIS API and Python, to return latitude and longitude of point?), but it deals with a more advanced approach.
In ArcGIS Desktop this is similar to the Calculate Geometry function; I just can't find where do this in QGIS.
Sure can. First, save the layer as WGS84 and import it again. Then in the field calculator you can use $x or $y as a variable to get the x and y.
NOTE: This was added in 1.7.
You have to reproject the point layer to EPSG:4326 first. Right-click on the layer name in layer list and select "Save as ...". There, you can specify the target CRS to be EPSG:4326.
Load the new reprojected point layer and then run "Export/Add Geometry Columns".
menu > Vector > Geometry Tools > Export / Add Geometry Columns
– clhenrick
Feb 25 '16 at 18:18
One option could be specifying the layer CRS as WGS 84(no projection). May be you will have to change the project CRS too. Now use "Vector > Geometry Tools > Export/Add Geometry Columns". This should give you Lat/long coordinates.
In QGIS 3.8 (June 2019), there is now an algorithm to add the X and Y values. It can reproject coordinates on the fly.
If you still need a Degree Minute or Degree Minute Second format, you need to use first the to_dm or to_dms expression to add these fields into the attribute table.
The most simple expression nowadays is this one for x | lon coordinate, if the layer is not already in the desired CRS:
x(transform($geometry, layer_property(@layer_name, 'crs'),'EPSG:4326'))
and
y(transform($geometry, layer_property(@layer_name, 'crs'),'EPSG:4326'))
for y | lat coordinate. You can use it for example in QGIS field calculator or anywhere else, where expressions are accepted. Simply replace EPSG:4326 by the EPSG-Code of the CRS you wish to display coordinates in. EPSG:4326 is the code for WGS 84, so it will return latitude and longitude.
Explanation:
transform() function transforms every known CRS to the specified destination CRS (here EPSG:4326 WGS 84). You can also type in every other known EPSG Code here instead. layer_property() function automatically detects the source layers CRS by 'crs' as well as the current layer name by @layer_name. x() and y() return the coordinates of the current $geometry.
If the layer already is in the CRS you wish to display coordinates in, the accepted answer still is the shortest expression, by using $x and $y.
Extract nodes. This makes it into a point layer. Then open attribute table, field calculate, Geometry-$y/$x
The previous best answer can be considered obsolete.
Using the field calculator, you can get x, y coordinates from points layer in any projection and make the conversion to longitude latitude.
You can find the recipe, documented with formulas and an illustrated GIF.
In the most recent version of QGIS, they added a feature called "Add X/Y Field to Layer" which (In this case you're wanting the lats/longs of a point layer) will add the latitude & longitude to your specified projection as x (longitude) & y (latitude) columns
For user like me, after 7+ years, there is a better and simple answer.
