Questions tagged [qgis]
QGIS is a cross-platform GIS application licensed under the GNU General Public License.
25,397
questions
4
votes
1answer
90 views
Making vertex at intersection points of lines from two layers using QGIS?
I have 2 layers of polylines representing a two road network called roads and routeir (Loaded to Qgis from 2 shapefiles). I want to insert vertices at the intersection points between the two polylines ...
0
votes
0answers
36 views
New GDB issues with QGIS 3.8
I just got a new MacBook Pro and installed QGIS 3.8 yesterday. I had several GDBs working on Ubuntu and QGIS 3.4 but that same GDB will not import in 3.8 on the MacBook Pro. They are vector layer ...
0
votes
1answer
40 views
Can't open QGIS 3.8 plugin manager on OSX
I have not been able to open the plugin manager in QGIS 3.8. I am running Sierra OSX. This is the message that I get when I try to open the plugin manager:
An error occurred during execution of ...
1
vote
1answer
30 views
Mosaicing non-overlapping rasters in QGIS
I have a set of georeferenced rasters that I want to combine in a seamless layer in QGIS. I believe what I have to do is clip them by mask layer and then build a virtual raster. There is an issue ...
3
votes
1answer
55 views
Using a virtual layer, display polygons based on location of another polygon layer
QGIS 3.4
I have a .gml file of every freehold title in a city outlined red below. I want to create a virtual layer of the freeholds which are contained within the blue-green isochrones. Even if a ...
2
votes
0answers
39 views
QGIS 3 system date format is not assumed
The system date format is 'dd/MM/yyyy', and QGIS recognizes this on the Options / General tab, however it does not assume this format anywhere else in itself. Any loaded feature that has a date or ...
1
vote
0answers
23 views
QGIS How to retain symbology when merging layers?
I have a QGIS project with various layers for which I have assigned icons. When I import additional data layers and then merge these layers with the existing layers (and their symbology) a new layer ...
0
votes
1answer
75 views
Save PostGIS login informations in QGIS
Does anyone know a way to save my username for PostGIS in QGIS, so I'll always be logged in without the need to enter my username and password everytime?
Anytime I start new project in QGIS, I need ...
3
votes
0answers
38 views
Setting input layers as PostGIS tables when building a model?
I am trying to build a QGIS 3.8 model where the same inputs are used each time and only the clipping layer extent changes.
I can do this using shapefiles and editing the script to use the same input ...
1
vote
2answers
76 views
Advanced street name labeling QGIS 3?
I have problem where the street text elements overlapping place text elements in QGIS. Both elements are in separate layers. How to express in QGIS 3 that street name layer wont overlapping place name ...
2
votes
1answer
44 views
Error converting vector shapefile to raster (.TIF) in QGIS?
I am working with a shapefile of 10km grid regions of the UK obtained from digimap.
I need to convert this to a raster in order to do some analysis in R regarding agricultural intensity of 10km UK ...
2
votes
2answers
44 views
Joining CSV to shapefile with same Name field results in NULL fields
I am having some issues with using the join feature between my shapefile polygons and my CSV data (originally a xlsx file), when I join the layers together using the common field between them (name) ...
2
votes
2answers
81 views
QGIS, Query out some attribute columns temporarily
I am looking for a work-around to remove some fields (attribute columns) from a layer's table by a query.
For example, there are 10 columns in a table, remove 9 and leave only one (virtually).
Now, ...
1
vote
1answer
35 views
QGIS spacing of individual labels
I'd like to increase the space between the symbol and the text for only one item in my legend; I can only seem to increases for all the items.
Specifically, I want to combine the two screen shots ...
0
votes
0answers
12 views
Adding file to data point using QGIS? [duplicate]
Is it possible with QGIS to link a data point on a map with a report of some kind (photo, pdf, graph etc) and that the file is accessible through a window?
I am interested in this feature, to ...
3
votes
2answers
81 views
Splitting feature says invalid geometry but Check Validity says its valid?
I am trying to split features in a shape file but I got an error message. I've had cases in other shape files where the message also appear. I then run the "Check Validity" option and rearrange the ...
1
vote
0answers
46 views
QGIS CRS for small island based on transformation with large rotations and tm-projection
I am trying to create a CRS for QGIS based on a GPSsurvey and the related transformation and rotation parameters. Within OSGEO I defined a transformation and projection as follows:
cct +proj=pipeline ...
2
votes
1answer
52 views
Can not finish to create new polygon by right click in QGIS
I am using QGIS 3.8.1 on Mac and trying to create new Polygon in this step. However it does not work.
Menu, Layer, Create Layer, New Create Temporary Scratch Layer
click toggle editing icon
click ...
2
votes
1answer
62 views
Turn Points with lat and long into polygon
I have a CSV file in which each row has a latitude and longitude. Each row is associated to a name of a polygon that the points form together.
How do I upload this file into QGIS?
2
votes
1answer
39 views
Displaying direction arrow on pointstopath in QGIS?
I found Displaying direction of movement with points2paths in QGIS? which should work but it doesn't. It looks as though it's an older version of QGIS (I'm using Madeira). Arrow gives a very strange ...
1
vote
1answer
41 views
Clipping converts multiband to single band
I have a multiband raster image. I am trying to extract the AOI by using "Clip raster with polygon" option in SAGA module. The process clips the raster to the exact size of the polygon but the ...
1
vote
1answer
30 views
Dividing up vector grid and scoring cells using QGIS?
I have a map of an area, have created a vector grid over this, and want to score different areas of the map by risk (high risk, medium risk, low risk), by scoring each cell. I want to define these ...
1
vote
1answer
28 views
Rotate raster in QGIS
I have two raster datasets of Antarctica, however, they do not match spatially as one of the raster should be rotates 90 degrees. Is there a way to do this in QGIS?
2
votes
2answers
32 views
Can´t categorize field for unknown reason
I am trying to categorize a field without any success
The values should be symbolized from 1-5 and yet, I just get that blank symbol.
at first I thought that the problem is that the column is defined ...
0
votes
0answers
26 views
Link multiple Photos to Features using ID in QGIS
In QGIS I have a Postgis layer with POIs. Further, I have a folder with images. The name of the images matches a unique identifier in the attribute table.
Is it possible to automatically connect ...
3
votes
0answers
41 views
Exporting to QField from QGIS?
In creating an export from QGIS 3.8.0 Zanzibar to Qfield using the sync plugin, I am encountering a strange error.
Each time I run the export, several of the layers I have in a geopackage in QGIS ...
0
votes
2answers
55 views
Get line length using SQL in QGIS
I have a line dataset that has road names and different surface types along different segments of the road. I want to calculate the total length of each surface type for each road.
I've been able to ...
1
vote
0answers
30 views
Created heatmaps are not displayed
I created a few heatmaps based on 2 different shapefiles( point layers). Then I joined the data from the 2 shp files, the joined file looks perfectly fine. I created a view heatmaps based on the new ...
0
votes
0answers
22 views
Font size in text annotation when exporting QGIS layouts to PDF or JPEG? [duplicate]
When I try to export a map from the Layout Manager in QGIS, all the elements apart from the text annotation come through fine. These come through as tiny objects, with tiny font.
I could put labels ...
1
vote
1answer
35 views
How to get values on a rastar layer to provide me with values
So I have received data from an external source for my work they have provided me with NDUI (plant productivity) with black being a lower value and white a higher value, however I am unsure on how to ...
0
votes
1answer
29 views
Adding a sketch in QField?
I want to use QField to collect data in the field. I need to draw some sketch and save it to the corresponding geometry (point in my case).
Is it possible to do that? Geopaparazzi is able but I don'...
0
votes
1answer
46 views
Adding dimensions to map in QGIS?
I would like to add dimensions to my QGIS map. It can be in the editing/drawing space or the print composer. I would like to see how long a line is, for example 3,5 m.
I tried a lot of different ...
1
vote
2answers
26 views
Highlight, count and delete overlapping point locations from different CSV layers in QGIS?
I have many CSV file layers in my project in QGIS, and quite a few layers have points which share the same location. Is there a way I can compare, count and highlight those "duplicates" and then ...
3
votes
1answer
42 views
Change data format in QGIS field calculator using format_date
I´d like to change the data format in the attribute table from yyyy-MM-dd (default) to dd.MM.yy using the format_date function in the field calculator.
Using:
format_date(date, 'dd.MM.yy')
I got ...
1
vote
1answer
37 views
Populating Route ID's in QGIS
I have a linear network of lines all digitized in the direction of flow and am trying to assign route ID's to segment groups. Is there an automated process to do this using QGIS?
0
votes
0answers
17 views
QField hyperlinks in Android
I am using QField for some mobile GIS on Android and would like to have a hyperlink in the attribute table that opens a file stored locally. If not in QField directly then in excel would work. None of ...
1
vote
1answer
25 views
'Unknown exception' when editing vector layers in QGIS [closed]
I keep coming across the unknown exception error message when trying to edit or add to a vector layer. Anyone else come across this problem? Any fixes? I'm currently running QGIS 3.4
0
votes
2answers
48 views
CRS for old Falklands maps in QGIS?
Does anybody know which CRS should be selected when georeferencing a Falklands map made in 1961? The map itself says only:
Grid: UTM Zone 21
Projection: Transverse Mercator
Spheroid: International
...
0
votes
2answers
26 views
Exporting heat map / texture maps as SVG without referenced PNG files?
When I create a map in QGIS and export it to SVG format, if there is a heat map or topographical texture map layer, those layers are exported as PNG files referenced by the SVG file.
Is there any ...
2
votes
1answer
23 views
Shapefile export of holes geometries in QGIS with wrong type MultiPolygon
I want to export a layer with holed geometries in it. But when I save my features to shapefile in QGIS 3 it creates a file with MultiPolygon as geometry type. The fact is that a holed polygon isn't a ...
1
vote
0answers
42 views
Map in QGIS is displayed tilted? [closed]
CRS is wgs 84 epsg:4326
Still the map and the data on screen is showing tilted.
1
vote
0answers
45 views
Seeking comprehensive information on how to create beautiful and artistic cartography? [closed]
In many circumstances I experienced how powerful maps can be because a key decision maker just enjoys looking at a beautiful representation of facts instead of reading 10 pages of text. I have a ...
2
votes
1answer
43 views
AIS Data Gaps - plotting as lines in QGIS
I am currently attempting to plot AIS data from our on board AIS receiver in QGIS.
My current processing steps are :-
Import the AIS data as a CSV file containing Time, Vessel Name, MMSI No, Lat &...
2
votes
1answer
70 views
QGIS equivalent to Mapinfo SQL qery
To run a simple interest query in Mapinfo I would use
Select * from _1_10000_map_sheet_key_map, Carpentaria_Shire where _1_10000_map_sheet_key_map.Obj Intersects Carpentaria_Shire.Obj into Selection
...
1
vote
1answer
39 views
Get more than 2 aggregate results in QGIS
I have an indexed grid and am using the following in field calculator to get a grid reference for each grid a road intersects.
It works fine except when the line intersects more than 2 grid cells. Is ...
1
vote
1answer
21 views
Using Multiple Raster Intermediate Inputs in Raster Calculator within QGIS Process Modeler
I am stringing together a series of raster calculations in the QGIS process modeler in order to calculate a surface temperature dataset from Landsat and weather data.
When I use the output from ...
2
votes
1answer
33 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#= ...
2
votes
0answers
24 views
Measuring distance from a point layer to a raster layer
I would like to calculate the distance (in meters) away camera traps (point layer) are to a water source.
Now the water source data I have been given via an external source from the national park I ...
0
votes
2answers
34 views
Key Map (creating overview map)
I would like to have a keymap in QGIS as in ArcGIS Desktop.
ArcGIS Desktop allows one to add two layers. You then load the main layer in the main map layout and another in the keymap and style them as ...
2
votes
0answers
43 views
Changed attribute order of PostGIS layer in QGIS
I'm working in a PostgreSQL table (PostGIS) that I loaded into QGIS. This layer has been created by a SQL Statement in pgAdmin.
I noticed that the order of attributes shown in the attribute table ...
