Calculating distance between points from CSV file in QGIS

Question

I have a CSV-file with latitudes and longitudes and I should calculate the distance between the points in ascending order (distance from 1 to 2, from 2 to 3, etc.)

I tried with the distance matrix but it calculates each point the distance with the others.

In addition, I am working in EPSG:23033 - ED50 / UTM zone 33N but when I made the distance matrix no measurement is returned. The ruler tool tells me that EPSG:7022 works automatically but I do not want to work with that CRS.

My initial CSV-file with 241rows looks like this:

I would like a new column.

Answer 1

Load you points to the project as described in step 1 of the solution by @Taras.

You can then automatically calculate the length you want without first reprojecting the points - this is done inside the expression with the transform function:

length (
    transform (
        make_line ( 
            geometry ( get_feature_by_id ( @layer, $id )),
            geometry ( get_feature_by_id ( @layer, $id+1 ))
        ),
    'EPSG:4326',
    'EPSG:23033'
    )
)

You can use this expression e.g. to set a dynamic label. If you want to create a new field, you must first save the layer in antother format (Geopackage, ShapeFile) as QGIS can't edit CSV files. If you reproject the layer during saving (see step 2 in the answer by @Taras), delete the transform () part of the expression (lines 2, 7 to 9 plus the , on line 6). If you leave the layer in EPSG:4326, use the expression exactly as stated above to get length values measured in EPSG:23033.

When you have the layer as Geopackage, use the expression with field calculator to create the new field.

When id + 1 exceeds the last number of a point feature, the result is a NULL value (no data): that is correct as the last point does not have a next point the measure a length.

Screenshot: as you see, the layer is a csv in EPSG:4326, the project is in EPSG:23033. Each point has a label that is dynamically generated by the expression above (plus a round function to get rid of decimals) that calculates the distance to the next point. The line between the points is also created dynamically with geometry generator, based on the same expression:

Answer 2

I assume that @Erik will agree with these basic steps:

1. Import CSV into QGIS, via Layer > Add layer > Add delimited text layer... using the EPSG:4326
2. Reproject your layer, e.g. use Export > Save features as... with the EPSG:23033 for 'CRS' (because your original layer seems to be in EPSG:4326). To avoid this step, see step 5.
3. Apply the 'Points to path' to your imported point layer, use "ID" as the 'Order field'.
4. Run the 'Explode lines' to split lines into linestrings
5. In the Attribute table calculate linestring's length using the $length. Otherwise try the transform() function, i.e. length(transform($geometry,'EPSG:4326','EPSG:23033')). This step was described by @Babel in his answer.
6. For getting back values from the original point layer, practise witchcraft with joins. Mind that there will be one-to-many connections because one linestring is a connection between two points.