Questions tagged [rule-based]
The rule-based tag has no usage guidance.
112
questions
1
vote
2answers
48 views
Rule-based symbology based on related layer in QGIS
I'm working with QGIS
I have two layers:
Layer 1: has the id and geom columns (multypolygon layer)
Layer 2: has the id, gid and type columns (table layer).
The value gid of layer 2 is the foreign ...
1
vote
1answer
17 views
Marker line in rule-based layer?
In a line layer, which is rule-based rendered : As I can see it, it is only possible to ad simple lines. I want to ad a marker line. Is that not possible ?
0
votes
0answers
19 views
Add categories classification to a rule
i'd like to add sub categories to a rule with automatic classification as i modifiy a field. Basically i want to give the chance to display each single new feature.
sorry for my english and thanks ...
3
votes
0answers
19 views
How to prevent not visible objects (scale rules) from being identified?
In Symbology tab I am using rule-based symbols and I have defined visibility rules dependent on the minimum scale. Above some scale threshold some features are not visible as I expected. But when I am ...
3
votes
1answer
49 views
Stretch label all along line length
I need to know if in QGIS 3.16 there is a method to stretch a label all along line length.
My layer has lines with different length and I want to know if is possible to stretch automatically labels ...
5
votes
1answer
66 views
Removing an empty entry rule by using QgsRuleBasedRenderer without affect other rules filled in PyQGIS?
I create rules with this code but it creates one more but without data and when using root_rule.removeChildAt (0) it deletes a correct one.
layer = iface.activeLayer()
symbol = QgsSymbol.defaultSymbol(...
0
votes
0answers
22 views
Move labels with rules generate overlap
If I move the layer's labels with the move label tool my label is overlapping. The labels are categorized by rule
My rule are based on two field "column1" and "column2"
I can't ...
10
votes
2answers
189 views
Rule-based symbology based on current selection in QGIS
I have two oracle layer (point(p1) and polygon(pl1)). I want to build a rule-based symbology which is based on current selection on two cases:
Case 1- When I select a point from table p1, I want that ...
1
vote
0answers
34 views
How can I load and draw predefined chart images (diagrams) rule based and related to a point vector layer with QGIS
I have a bunch of diagrams for a set of route segments, stored as PNG, PDF or SVG with a regular name (topic-segment-id.(png|pdf|svg) for example), representing a certain aspect (like crossing rate or ...
1
vote
0answers
19 views
Action on filtered objects QGIS
I have got a point layer with about 1000 points. These point has a rule based symbology. So far so common.
In this layer I have also some actions implemented. If I unselect some rules, that only the ...
2
votes
1answer
48 views
Rule Based styling with different forms and colors
I have a map about different locations of amphibians. I want that the colors illustrates the specific species and the form illustrates the stadium (young, adult). I know how to give different colors ...
1
vote
1answer
34 views
QGIS Symbology: how to make a symbol a shape according to a set of rules and a color according to another set of rules
I'm using QGIS 3.14 with GRASS 7.8.3. I have a data set with point coordinates on a plan (artifacts on an archaeological site). I have two main variables that I want to show. So, I'd like to have the ...
2
votes
2answers
80 views
Symbology Based on Meeting Criteria
I have a dataset that includes populations and subpopulations, so for each main population there may be several subpopulations. I have organised this in the table so that a population has the same ...
8
votes
1answer
481 views
Place label along line near start and end of line in QGIS
I have four fields managing the numbering of the start and end of road sections.
I created two label rules, one for the start and one for the end of the road sections.
I set the position of the ...
4
votes
1answer
1k views
Rule-based symbology in QGIS
I'm trying to create the following rule based expression for displaying a line :
If column "riparian Veg"has a 'Yes' entered into it then display the line but if another column titled "Primary" has '...
3
votes
1answer
64 views
Applying Rule-Based Style taken from another layer to layer with no geometry
I have two layers
"Suburb_Type", that has more than 1000 suburbs in shapes and is styled with categorisation rule. (columns: 'suburb_code', 'geometry', 'category_variable')
"Suburbs_in_Study", with ...
1
vote
2answers
127 views
Qgis 3 - Rule-base labeling combining to backgrounds
I have a pointlayer with no symbology, but is labeled by numbers 1-74. The labels is styled with a circle background. For some of the points I need to keep the circle, but add a small SVG-symbol to ...
1
vote
1answer
36 views
Change/Hide the pen width for line shape file based on rule in QGIS
I have line shapefile, in which I have a condition to display line's width based on a rule as shown in the image below. But in this case I was not able to define line width to 0, it is taking hairline ...
0
votes
1answer
102 views
How to run multi level segmentation for LULC in process tree, eCognition software
Can we run the eCognition multi level (level 1 ,level 2,...) segmentation and classification in the same process tree? I want different outputs to show for each levels in a process tree. I'm in the ...
1
vote
0answers
65 views
Using 1:n table relationships in rule-based symbology
I would like to use the value of a field/attribute in a parent table as a filter in an expression used to display features in the child table.
Specifically, I have a 1:n relationship in my project:
...
0
votes
1answer
47 views
Labeling by using different columns
I try to label a layer by using a rule based labeling. What I specifically try to do is to find an expression which says:
"If column 1 shows the attribut x then label layer "Test" by the attribute of ...
1
vote
1answer
29 views
QGIS different scale levels in rule-based styling - in one rule
I have a layer with 4 roadclasses. For this layer I created a rule based symbolization, with 4 rules. In every rule I filter another roadclass and set a different symbolization and scale for this rule....
1
vote
1answer
54 views
QGIS rule based styling - rule ordering
I’m experimenting with some rule based styling which is working really well to a point but I’m hoping it can do more. I work in school transport I’ve plotted all pupils in a certain school on the map. ...
1
vote
0answers
25 views
QGIS 3.4 - Symbology expression for features that have not been styled by rules [duplicate]
I have a rule based set of expressions for styling a map according to the contents of the 'Layer' field. e.g if the Layer starts with a 'C'
"Layer" ILIKE 'C%' colours the line red.
Is it possible ...
3
votes
1answer
202 views
Using Rule-based/Geometry generator style in QGIS
I have layer for comments in qgis, symbology style is rule based with Geometry generator.
Problem is with displaying name in layers tab because the line before text is too long
How do I solve the ...
1
vote
0answers
39 views
Labeling rule depending on whether label fits in polygon
I'm labeling some country polygons with their names. The data have one attribute with the full country name and another one with a short version (e.g. Sweden/SE). I want to label the countries with ...
2
votes
0answers
95 views
Projecting GeoTIFF onto shaped roofs using CGA rules
I am working with CityEngine 2019.1 and would like to project a GeoTIFF as a texutre onto shaped roofs of 3D-buildings. Currently I am trying with the following code which essentials are described on ...
0
votes
0answers
88 views
How to set fixed distance labels from data defined centroid in QGIS (3.4)
I have a labelling issue in QGIS (using 3.4, but haven't tried in other versions). I have polygons for which I show an id number as well as some data information in the labels. I've used rule-based ...
3
votes
2answers
225 views
Save Rule Based Symbology as Default Layer Style
I am constantly moving layers in and out of my projects, I was able to set default style for layers and they all the layers I drag and drop to my project get the same style by default.
Lately I have ...
3
votes
1answer
66 views
Labeling only maximum value when zoomed out or print in smaller scale
I would like to prioritise the maximum values to be shown on the map. In other words, when the label collides it should drop out the minimum values.
In the shown examples, I would like to have ...
3
votes
1answer
77 views
Using the field calculator in rule based symbology
I am trying to categorise my site points by species group with rule based symbology;
e.g. bat uses the formula
"Group"='Bat'
But I would also like to have a different symbol for where there are ...
5
votes
1answer
154 views
Rule-based labeling with optional second field
I need to label some polygons with 2 fields using only one label:
The first being a field in the attribute table named "Bio-Code" the second one being optional if a cell in the field "BBT-Code" is ...
2
votes
2answers
193 views
How to export layers with rule based symbology with qgis2web
I am working as volunteer on a simple map for an NGO, I have some point layers with rule-based symbology. When I load these layers in qgis2web the symbology disappears, both in Leaflet and OpenLayers. ...
8
votes
1answer
173 views
QGIS can't detect negative values?
I'm working with the last version of QGIS (3.8.3-Zanzibar), and I'm trying to represent a Rule-Based Symbology from a CSV file with the following rules:
And the data from the prcptot column is this:
...
3
votes
1answer
241 views
Can qgis2web display rule-based layer style?
I’ve just made a map that has two layers: one that contains the polygons and other that contains points. For the last one, I used rule-based symbology where I define the size and colour of the points ...
1
vote
1answer
295 views
Line at map scale that do not vanish when zoomed out? (QGIS 3.8)
I'm drawing rivers and roads as linestrings with width set in map units from an attribute.
When zooming out, of course they vanish quickly, because 10, 20 or 100m is less than a pixel at 1:100,000
...
6
votes
2answers
501 views
QGIS styling a legend
I am a newbie working on QGIS 3.6 / Windows 10
I need to style a legend for map with headings and sub headings
The main divisions of the legend item need to be subdivided into sub-classes
i.e. The ...
3
votes
6answers
985 views
Rule based coloured background for labeling in QGIS
I am a newbie working on QGIS 3.6 / Windows 10. I need to label a polygon layer which is categorised by colour.
(pls refer to attached pic as a graphical reference)
The labels need to have a ...
0
votes
0answers
80 views
QGIS Rule-Based styles fail to render
I'm working with some Ordnance Survey data, specifically the VectorMap Local (in GML format, October 2018) set and attempting to style the layers using the very handy OS provided stylesheets (here: OS ...
2
votes
1answer
101 views
Features color based on layer's color in QGIS
Is there a way to synchronize the selection color with a layer's color in QGIS?.
Following this post https://gis.stackexchange.com/questions/111784/displaying-only-selected-features-on-map-in-qgis#= ...
1
vote
1answer
41 views
Drilling Rigs Rule-Based Styling
I am trying to do rule-based styling for active drilling rigs in the United States.
Basically, I want to have categorized styling (different colored dots) for all companies (field = "OpCompany") ...
2
votes
0answers
57 views
Moving individual labels & rule-based labelling in QGIS
I have been playing around with labels and came to a problem. Hopefully someone can pinpoint whether I'm doing something wrong or there is a systemic hurdle in Qgis.
Are you allowed to move labels ...
4
votes
1answer
99 views
QGIS Draw by rule
I have a point layer with several colored dots. Each dot represent a find of a bumblebee species. E.g.
red is B.terrestris
yellow is B.hypnorum.
In my attribute table I have a column named "nest" (...
2
votes
1answer
128 views
Catching signal when rule toggles (active/inactive) using PyQGIS?
I would like to catch a signal when a rule within a rule based layer toggles visibility. How to permanently check this
layer.renderer().rootRule().children()[0].active()==True
the same way we can ...
2
votes
1answer
150 views
Possible to set color based on attribute while using 2.5D symbology?
I'm using 2.5D symbology to have my features display at different heights based on a certain attribute, but would also like the features displayed as different colors based on another attribute.
Is ...
1
vote
1answer
242 views
Rule-based labeling using Atlas - QGIS.3.6.2
I'm working with two shapes, both of them have a common field called "ID". I need the atlas to filter, only the id that I need to use, in the two layers.
The point layer has an entry point and an ...
1
vote
2answers
53 views
How to make appear values above the mean on rule based labeling QGIS
I've been looking at the other questions relating to rule based labeling but I haven't found any answer to my query.
I have polygons with average literacy rate for each canton of a country and ...
5
votes
1answer
151 views
Nested rules in QGIS 2.18
I work with QGIS 2.18. I have a polygon shapefile with two atrributes: id (unique for each polygon) and type.
I visualize the shapefile using the "type" attribute, but I would like to add a nested ...
0
votes
1answer
70 views
Style a feature in one layer based on an attribute in another layer in Print Composer Atlas
I have two layers; one is the foreground and the other a background. Both layers have fields containing similar values (field values in the foreground layer (mun_code) is also present in the ...
1
vote
0answers
38 views
Detecting checking/unchecking of rules in a rule-based rendering using PyQgis [closed]
Is it possible to programmatically detect checking/unchecking changes of a rule in a rule-based rendering ? I found no indication of existing signals ..
I got lost reading QgsVectorLayerRenderer ...
