How to extract coordinate information of a point from QGIS

Question

I need to know how to get a geographic coordinate from a point, extracting it from EPSG:31982 in degrees, minutes and seconds.

Have you read the official documentation on the transform-expression? — Erik, Mar 28 '22 at 13:14
Coordinates in UTM have to be deprojected to be represented in a geographic coordinate system before you can display in DMS. — Vince, Mar 28 '22 at 13:26
Do you mean a data point in a loaded vector layer of points, or some random location clicked on the map? Where do you want to get it to? An attribute column of some data, plain text, popup on screen? — Spacedman, Mar 28 '22 at 14:04
I meant a data point in a loaded vector layer of points. As a attribute column/plain text. — Fernando Santiago do Prado, Mar 28 '22 at 14:12

hgb · Answer 1 · 2022-03-28T17:14:57.410

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You can reproject the longitude and latitude coordinates from the layer's geometry directly to create a new column for each using the QGIS field calculator.

This is explained here: https://gis.stackexchange.com/a/375071/110158

The field calculator dialogue for the longitude column is shown below:

That gets you to the longitude coordinate in decimal degrees. To get to degrees-minutes-seconds, as you requested, take the result from above and pass it into to_dms(). The complete field expression becomes:

to_dms(x(transform($geometry, layer_property(@layer, 'crs'),'EPSG:4326')), 'x', 3)

Or, as Matt suggested, layer_property(@layer, 'crs') can be shortened to @layer_crs making the full expression:

to_dms(x(transform($geometry, @layer_crs,'EPSG:4326')), 'x', 3)

Documentation for to_dms. This will return a text value so make sure you create a new text field or update an existing text field with space for the text.

edited Mar 28 '22 at 17:14

answered Mar 28 '22 at 15:14

hgb

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Great! I was to post a similar answer, but you were faster. Nice to include layer_property so that you can transform without even knowing from what CRS you transform! – Babel Mar 28 '22 at 15:17
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There is also the named variable @layer_crs for an even tidier expression. – Matt Mar 28 '22 at 17:07
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@Matt, thanks for the suggestion. I did notice @layer_crs when looking up to_dms(). Edited to add the alternative expression . – hgb Mar 28 '22 at 17:16

How to extract coordinate information of a point from QGIS

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