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Questions tagged [qgis]

QGIS is a cross-platform GIS application licensed under the GNU General Public License.

1
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0answers
18 views

Read a .csv file from a URL with an API call in QGIS 3?

How do I read a .csv file from a URL with an API call, including key, in QGIS 3? I've tried creating a .vrt file as outlined here I've tried the solutions presented here If I'm doing everything ...
2
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1answer
33 views

How to create an index map of atlas features in QGIS 3?

I realise that this question has been asked before (Making overview with linked detailed maps in QGIS?), however I am still unable to figure out how to create an index map of atlas features in the ...
1
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0answers
25 views

QGIS 3.45 Layers Panel point data labels set too far apart

The Layers Panel in v 2.18 is fine but we are now trying to go live with 3.45 and are experiencing issues with the display of some layers in the panel. Layers that are generated from an MSSQL spatial ...
1
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1answer
24 views

Rasterize produces wrong result - R

I am trying to rasterize a polygon in R using teh rasterize function but the output is not correct. I am comparing the result with the output produced by the rasterize tool available in QGIS May data ...
2
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0answers
47 views

Migrate QGIS2 projects to QGIS3

I have about 40 QGIS2 projects. If I open them with QGIS3 labels and svg icons are not displayed. I don't know if there is any other feature that is not working when upgrading to QGIS3, but I suppose ...
0
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2answers
21 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 ...
1
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1answer
10 views

Discard changes when feature added programmatically (pyqgis)

I made a tool that adds some features into a layer which has to be in an edit session. But also noticed that if I want to stop edit session without saving changes my new features still exist in layer. ...
3
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3answers
1k views

Install QGIS 3.x on Ubuntu 18.04

I've tried several packages including ubuntugis but none helped. How to install qgis 3.x, more preferably qgis 3.4 lts in Ubuntu? I've added following repos:: sudo add-apt-repository ppa:ubuntugis/...
1
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1answer
44 views

Update Existing Field Editing Changes Don't Persist in QGIS

I toggle editing on a layer, open the attribute table -> Field Calculator -> Check 'Update Existing Field' -> Select 'myfield' in dropdown -> type... myfield / 60 -> Hit 'Ok' -> Save Edits -> Stop ...
0
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0answers
8 views

Suppress QgsTask “Task Complete” notification

I'm following the Extending QgsTask example to create a custom QgsTask. However, I don't want it to display the Task Complete notification* every time the task completes successfully. Is it possible ...
0
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0answers
13 views

How can I extract the coordinates from one layer and import them in a diferent layer when key field is the same?

I'm working with 2 different layers. First one is a csv file with 3 fields. Name, longitude and latitude. Second is a text file with the field name. I want to assign the longitude and latitude ...
0
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1answer
19 views

When using a Wacom Cintiq tablet and pen, can you pan while creating a feature using the freehand polygon plug-in in QGIS?

Is there a way to pause the free-hand tool in QGIS so that i can pan and move over the image and then continue my polygon?
1
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0answers
40 views

How to render vector data with muliple geometry types to georefrenced raster

I am using OSM vector data which has been converted into shapefiles. I have polygons representing buildings, landuse and lines representing roads as shown bellow: I want to assign some symbology to ...
4
votes
2answers
287 views

How to use gridfiles (*.gsb) in QGIS

When opening a data source in EPSG:25832 in a project with crs set to EPSG:31468 I'm prompted to select a datum transformation (e.g. +nadgrids=BETA2007.gsb) The nationwide standardized gridfile for ...
1
vote
1answer
22 views

Showing Outline of Island on Topographical Contour Map using QGIS?

I am fairly new to GIS. I have been reading through this site and have not quite been able to figure out what I am doing wrong. I am trying to create a contoured topographical map that I can cut ...
1
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0answers
19 views

How to determine the status of snapping in QGIS 3?

I can use toggleEnabled to turn snapping on and off, but is there anyway to know the status of the snapping tool (on or off)? as toggleEnabled doesn't return a value nor does it take a value.
2
votes
1answer
27 views

QGIS 2.18 label by expression concatenate field strings

For a building layer I have an attribute table with several fields for the building type where data was entered with a manually created form using checkboxes. Example: Production: 1 = (yes), 0 = (no) ...
0
votes
1answer
17 views

How to change PostgreSQL layer encoding for QGIS Server

I'm actually stuck trying to update encoding of my PostgreSQL layers to be able to set my project as QGIS server project. In the layers properties, I can't change the layer's encoding. Any hints on ...
1
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1answer
20 views

What is the search mechanism in “join attributes by location”?

While running join attributes by location, we can either choose one to many or one to one mapping. In One-to-one, it assigns the first located features value. What is meant by first located feature? ...
0
votes
2answers
36 views

Joining QGIS Property Parcel Mapping shapefile to an Excel file and displaying symbol in Parcel Mapping Shapefile

I am new to QGIS. I am a land surveyor and I have all of the property parcel mapping information in a shape file for my area. I am trying to link/join an Excel file which has all of the survey files ...
-1
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0answers
23 views

SAGA - QGIS open DLL

Is possible to load SAGA io_shapes.dll directly to tool in QGIS 3.6? I need export line shapes to xyz points.
0
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0answers
21 views

From point with z value to “3D” line in QGIS [on hold]

Image to have a point layer with z values and you want to convert this point layer to a line layer. Each line layer node should contain the z value of the point layer. Is this easily achievable in ...
0
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0answers
20 views

Strange values after vector to raster QGIS

I have tried to rasterize a vector file made by polygons, each one with own temperature value, but I got a raster with different values. In addition, the min and max values do not correspond to the ...
3
votes
1answer
425 views

Group multiple rasters in MapServer?

I had a map file for each state (raster file) of India. Now I want to group all map files to show a single raster or single map file? How I can do in using QGIS or any platform?.
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0answers
32 views

Possibly wrong expression defined [on hold]

I have written code but it is not returning any value in the plugin. def btn_nuf_pressed(self): layer = geo_utils.LayerUtils.get_lay_from_id(self.cbo_layer.itemData(self.cbo_layer.currentIndex())...
0
votes
1answer
20 views

How to perform viewshed analysis for each pixel in raster?

I am having a problem making a viewshed analysis for every pixel on a raster. To perform the viewshed analysis from every single pixel in a raster I will need: A viewshed plugin (which I am willing ...
1
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0answers
24 views

How to solve this error?

I am getting this error message : "Processing algorithm… Algorithm 'Warp (reproject)' starting… Input parameters: { 'DATA_TYPE' : 0, 'EXTRA' : '', 'INPUT' : 'C:/Users/DELL/Documents/Geodata/mosic.vrt'...
2
votes
1answer
78 views

How to dissolve shared line segments together in QGIS?

I have 2 features which are lines on a single layer re-projected to ESPG:2039. I wish to combine them into one MultiLineString but in a way that their common part is merged to a single LineString. I'...
0
votes
0answers
12 views

Printing shows extra lines on Print or ExportToBitmap

I am trying to print the following map (from LayoutControl) But the actual output is different from expected one as below There are extra lines and missing lines in resulting print. I am creating ...
20
votes
2answers
8k views

Setting print layout to portrait using QGIS 3?

I can't get the print layout to appear in portrait. It opens in landscape and Layout/Page Setup... allows for portrait, but the layout canvas remains in landscape. In 2.18 the "Composition" Panel ...
3
votes
1answer
164 views

QGIS v.net.steiner 'not correctly generated' error

I'm trying to generate a Steiner tree in QGIS 2.18.2 using a simple set of points, and a simple line vector. See the screen shot below: I then open up v.net.steiner, set the points and vector ...
-1
votes
0answers
16 views

Python error : Couldn't load plugin 'processing' See message log (Python Error) for more details [on hold]

2019-04-23T19:14:57 WARNING Failed to load C:/PROGRA~1/QGIS 3.4/apps/qgis-ltr/plugins/grassplugin7.dll (Reason: Cannot load library C:\PROGRA~1\QGIS 3.4\apps\qgis-ltr\plugins\grassplugin7.dll: ...
0
votes
1answer
153 views

QGIS Distance Matrix execution fails

I am trying to use the distance matrix to measure the distance between a crime (input ID) to the closest subway entrance (target layer). The problem is that sometimes the matrix comes out with results,...
3
votes
1answer
34 views

QGIS install on OSX with homebrew: “You have other linked versions!”

I have an OSX Mojave setup where I've already installed PostGIS and GDAL using Homebrew. Now I'd like to install QGIS. I'm trying: brew install qgis But... I'm getting lots of warnings of the form: ...
0
votes
0answers
31 views

Filtering attribute table in QGIS Atlas?

I have encountered a problem with filtering "show only features visible within a map" in QGIS Atlas ?composer. I need to have an attribute table with all mileage posts visible within one map. ...
0
votes
1answer
177 views

SQL Server Geography Tables Not Connecting

This has me totally confused... it was working last week, isn't working now. Using QGIS v3.0 and 3.2 and no love. Even tried 2.18.21... no difference. Follow the pictures... This is my connection ...
0
votes
1answer
179 views

Understanding the app schema for using complex features in QGIS

I'm working with complex features on the GeoServer and the app schema extension. My understanding of the app-schema extension is that you are able to map complex features through a WFS at the end. ...
1
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0answers
36 views

How to use ATOM FEED Data in QGIS 3.6.1?

I would like to know how I can work with ATOM FEED Data in QGIS. In ealier QGIS versions this worked with the Plugin "INSPIRE ATOM Client", but this Plugin doesn't work in the current version. An ...
1
vote
3answers
44 views

Showing two sets of points from two different fields in QGIS?

I made a union of two adjacent shp (points) files with the same theme (Geochemistry) so the resulting attribute table gave duplicated fields, for example: ID, As_ppm, Ag_ppm, Pb_ppm, ... , ID_2, ...
2
votes
1answer
194 views

Programmatically “locking” map layout in composer of QGIS 3?

I am programming a plugin for Qgis 3 from which I want to export a composer layout containing different maps that are supposed to have different extends and show different layers. I am having ...
3
votes
3answers
3k views

“Node tool: could not snap to a segment on the current layer” message

I have a strange issue. Editing a layer with node tool I get always the following message: "Node tool: could not snap to a segment on the current layer." This error happens to me even with a fresh ...
1
vote
0answers
62 views

Exporting from QGIS to .dxf as blocks

I'm exporting from QGIS 3.4 to ACAD .dxf format. Since I made this in QGIS 2.18 all features exported were blocks in Autocad, but now I find out that every single geometry is exported explosed in the ....
1
vote
1answer
79 views

Change visibility of attribute field/group of field in one layer based on checkbox or value map - QGIS

i'm using QGIS 2.18.3, in Win 7. i want to know how to make attribute field or group of fields become visible or invisible based on value of other field on picture above, i want to make my grup ...
1
vote
1answer
32 views

The Logic Marker Moving with the Offset Function in QGIS 3.6.2

In QGIS the location of the marker can be changed, without changing the coordinates in the Attribute Table. This is done by changing the X or Y values in the Offset function, located in the Layer ...
2
votes
3answers
304 views

Dividing a buffer into segments based on path and distance

I have a buffer layer which I generated from a polyline layer and then dissolved. I then rasterized the dissolved buffer layer, thinned it based on this link and generated a new (more approximate) ...
1
vote
1answer
80 views

Rounding numbers in QGIS raster legend?

Is it possible to have the numbers in the raster legend automatically rounded off? In the example below I'd like the labels to be 8, 29, 51 and so on. I know I can manually edit the labels, but is ...
1
vote
0answers
33 views

Changing the field colour/design on a QGIS 3 QT attribute form?

I have problems with changing the physical appearance of a custom attribute form (QGIS 3, Windows 7). A custom attribute form can be designed, for use in QGIS, using QT / QT Designer. In QT Designer ...
0
votes
0answers
31 views

SDO Oracle Table not recognized as Geometry in QGIS

I can connect to the Oracle Database with QGIS but spatial table/layers are not recognized as such. I have read the following in the QGIS documentation: Normally, an Oracle Spatial layer is ...
0
votes
1answer
118 views

QGIS - Script for Process Modeler, Output = Extent

just played arround a little bit with the process modeler and scripts to automate a simple workflow. I have created a simple script that should get the extent of the current layer, and then increase ...
0
votes
0answers
9 views

QGIS OpenCL and eGPU on Mac [on hold]

I'm using a Mac Mini with a Radeon RX Vega 64 as external GPU but the OpenCL Acceleration doesn't seem to be supported. Does anyone know if QGIS lacks support for this chipset or is there anything I ...