QGIS Labeling – How to Avoid Labels on Short Lines

labelingqgis

I have a road map in QGIS (v 3.22.1). I want to put labels on the roads, but since I get a label on each line segment there will be too many labels when there are many short segments, for example on highway crossing.

How can I avoid this? I am using a rule based labeling, so I thought

"vegkategori" = 'E' and length($geometry) > 2000

would stop labels on lines shorter than 2000m, but no. ($length neither did work).

Is there some other way of filtering out labels on short lines? – or what would be perfect – a minimum distance between labels on the same data set.

Best Answer

It is a native feature in QGIS. Select your layer, right-click > Properties > Label. Then select Rendering and scroll down.

You will fine the wanted option (blue color on screenshot). A nice alternative would be to connect lines to prevent unwanted labels (green color on screenshot) Merge connected lines to avoid duplicate labels

Related Solutions

[GIS] Rearranging labels in screen to avoid overlapping

Here is a good paper which has a C++ focus. It seems very detailed, 147 pages.Automated Label Placement In Theory and Practice

QGIS Labeling – How to Avoid Empty Lines in QGIS Labels

The advantage of this solution is that it works automatically, without any manual intervention: you can use the expression without any change regardless how your fields are named and how many fields you add (or delete or rename).

So to automatize the process and avoid the need to manually repeat the expression for every single attribute field, you can use the functions attributes() and map_akeys() to get a list of all fieldnames.

Then check which of these fields contain the value true and return the names of of these fields only. Use this expression that will output a list with each fieldname in a separate row, avoiding any empty rows:

array_to_string (
    array_filter (
        array_foreach(
            map_akeys(attributes()),
            if (
                attribute (
                    get_feature_by_id (@layer, $id),
                    @element
                )='true',
                @element,
                ''
            )
        ), 
        @element <>''
    ),
    delimiter:='\n'
)

The expression, used here as source of a dynamic label. It takes into consideration only those fields that contain as value the text string true and in this case returns the fieldname, with each name on a separate row, but without any empty rows:

Best Answer

Related Solutions

[GIS] Rearranging labels in screen to avoid overlapping

QGIS Labeling – How to Avoid Empty Lines in QGIS Labels

Related Question