Questions tagged [qgis]
QGIS is a cross-platform GIS application licensed under the GNU General Public License.
6,457
questions
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votes
2
answers
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How do I check which version of GDAL I have and how many?
I have installed in my computer the following software:
PosgresSQL 9.3.2.3
PostGIS 2.1.1.1
QGIS 2.0.1 Dufour (this one installed through the OSGeo4w package)
QGIS 1.7.0 Wroclaw
As far as I know all ...
- 1,545
50
votes
1
answer
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views
Using GeoPackage instead of SpatiaLite, and vice-versa?
I am using now QGIS 2.18, which includes support for GeoPackage format.
I know that GeoPackage is like a replacement for Shapefile but not quite so, as GeoPackage has database capabilities. At same ...
- 654
48
votes
8
answers
27k
views
Comparing QGIS and gvSIG? [closed]
Many debutant GIS users are asking me which one is better QGIS or gvSIG. Since I use Qgis and I don't have any experience in gvSIG, I aways say that both are very nice softwares and the chose is a ...
38
votes
9
answers
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Can QGIS open KMZ files?
I know I can add KML files once I have unzipped the KMZ files, but is there a way to open KMZ files directly?
When I try to open a kmz file on QGIS 1.8.0 on Windows XP, through the all files filter, ...
- 573
36
votes
5
answers
21k
views
Is there a way to render lines with a smooth (bezier) curves in QGIS?
I am moving from creating maps with Illustrator to making them with QGIS and actual data. One of the things I haven't been able to re-create in QGIS are the smooth curved lines I can get in ...
- 1,941
34
votes
3
answers
20k
views
How to easily edit attribute data using Regular Expressions?
I am writing a tutorial for MSc students that uses QGIS.
One of the tasks requires the attribute data to be modified
(see pdf draft of tutorial here if interested ).
The question is how to get them ...
- 4,254
33
votes
3
answers
58k
views
How to Add OSM Layer to QGIS 2.X
How can i add OSM layer in QGIS?
The help says there is an OSM plugin i can use. But i don't see it the list of plugins.
Or maybe there is a WMS URL for OSM i can use?
QGIS version 1.7.0-Wroclaw ...
- 13.3k
32
votes
3
answers
55k
views
Copy a geometry from one feature to another without attributes?
With QGIS it's easy to add a new part to an existing feature/geometry but I can't see how to copy/paste this part from another existing feature/geometry.
Is it possible?
- 515
31
votes
6
answers
36k
views
Changing Data Source of Layer in QGIS
Is there a way to source a shapefile to a layer file in QGIS much like how you do this in the properties of an ArcGIS layer? (i.e. Go to layer properties, source tab and then just depress the 'Set Dat ...
- 2,281
28
votes
4
answers
11k
views
Seeking model builder for QGIS?
Like the ModelBuilder of ArcGIS Desktop to run simultaneous geoprocessing tools, is there any model builder available in QGIS?
- 3,379
26
votes
5
answers
12k
views
Obtaining print quality PDF or PNG output from QGIS?
I work with people who use ArcGIS Desktop and they have found the best resolution output images are made by creating PDFs. They tell me that *.png and the rest out of ArcGIS Desktop are not ...
- 1,772
26
votes
5
answers
23k
views
Install QGIS 2.14 Essen on Ubuntu 16.04 Xenial
I'm having trouble installing QGIS on Xenial.
`debian` release
When I try using the debian release (i.e. without ubuntugis dependencies) I get the following errors (please note there is no xenial ...
- 1,129
25
votes
3
answers
21k
views
Making QGIS layer update from changed data source
I'm trying to get layers to update automatically when their data source changes. I'm using R to write a shapefile with an attribute, and colouring according to that attribute in QGIS.
I want to write ...
- 63.9k
24
votes
10
answers
13k
views
Sorting by multiple fields at same time in QGIS?
Is it possible to sort multiple fields at the same time in QGIS?
For example, I'd like to sort a table by state name, and then within each state, sort by county name.
This would be the same as ...
- 8,302
22
votes
2
answers
11k
views
Having drop down list for feature editing (attributes) in QGIS
I'm editing a lot of polygons of a shapefile in QGIS and I need to classify them, so I have to write the classes repeatedly. In ArcMap there is an option to have domains set for the fields.
How do I ...
- 5,570
21
votes
1
answer
33k
views
Exporting map with transparent background in QGIS
I have gone into Composer and specified the page background to be transparent. It still comes out white. Is there a solution?
- 335
20
votes
5
answers
10k
views
Manually correcting raster DEM (OpenSource)?
Is it possible, to correct a raster DEM by changeing the raster-cell-values manually, like by "painting"?
My DEM (ASTER) have one small error where the elevation is about 300m below the actual ...
- 8,262
20
votes
2
answers
24k
views
How to split non-contiguous feature in QGIS?
I have a shapefile with a feature that is non-contiguous. I want to split the areas on the left from the area on the right. However, QGIS's Split Features tool requires you to draw a line over the ...
- 1,103
19
votes
4
answers
12k
views
Changing QGIS plugin's icon, why doesn't it change in the menu/toolbar?
I've been writing a QGIS plugin (using the "Plugin Builder" plugin), and decided I wanted to change the icon (icon.png).
After running make deploy to rebuild the plugin locally, the new icon appears ...
- 20.4k
19
votes
3
answers
4k
views
Determining what lines have changed in updated shapefile using QGIS
I am using my county's GIS data to update the roads in OpenStreetMap. I have a copy they published last year and one that was just published, and I would like to find all the LineStrings that have ...
- 909
19
votes
1
answer
12k
views
How to display geoJSON from an URL in a layer?
I am looking for some type of plugin or code which would allow me to add a geojson URL, define the areas to input the lat/long variables from the visible Qgis canvas map and call/render the results ...
- 2,320
18
votes
3
answers
8k
views
How to bulk import gpx files to QGIS and merge into a single shapefile?
I am looking to create my own 'heatmap' of all the bike rides I have recorded using the app Strava in QGIS.
I have over 450 individual gpx files and would like to merge the track points layers into ...
- 377
18
votes
2
answers
73k
views
Multiple labels for one layer in QGIS [duplicate]
Is it possible to show two or more labels for one layer?
For example - one label will show the name of a school and the 2nd label will show the number of students? They should be completely different ...
- 1,009
18
votes
2
answers
17k
views
Creating drop down list with values in QGIS
I want to show a drop down list in the feature attributes dialog.
I have three different building zones. The hot Wohnzon A, B residential zone and residential zone C. Now I have an attribute called ...
- 603
18
votes
4
answers
18k
views
Filter features based on their attributes using Python
How to get features by their attributes (similar to 'IQueryFilter' in ArcObjects) in QGIS using Python? Instead of getting all features and filter it manually, is there any option to use where clause ...
- 1,051
17
votes
3
answers
8k
views
How to refresh the attribute table of a layer after editing the table in the DB-Manager?
Is there any way to refresh the attribute table of a layer after editing the table (e.g. add a column) in the DB-Manager?
- 1,986
17
votes
3
answers
8k
views
Is there any way to include "universal" style/symbology in GeoPackage?
I am just playing with the GeoPackage format in QGIS. In QGIS it works nice with the style saved from QGIS but if I load it for example in SAGA the style is not applied.
Is there any way to include ...
- 1,738
17
votes
2
answers
4k
views
Automatically style raster using unique values in QGIS?
In ArcMap, it is possible to automatically calculate the unique values for a raster and then apply a different style to each unique value (see 1st image).
However, in QGIS, I have to manually add ...
- 292
17
votes
2
answers
24k
views
Summing values in field using QGIS
Using QGIS 1.8, I've got a shapefile with an integer field called "AREA" and I'd like to sum the values which are in this shapefile.
Does anybody know how to?
- 171
16
votes
3
answers
6k
views
Creating Spatial Index for GeoPackage using QGIS
Working in QGIS 2.18.14 standalone on Windows, is there a way to create a Spatial Index for GeoPackage (gpkg) layers?
- 30.8k
16
votes
2
answers
639
views
Transferring flows (connections and values) between polygons in QGIS
In QGIS there are two shapefiles representing the moving data between cells and one additional layer, see image below
Moving data defined by:
A polygon 'LayerA' (transparent squares with red outline)...
- 32.8k
16
votes
2
answers
2k
views
How to overcome field truncation when converting OSM to shapefile with QGIS?
I am trying to convert an OpenStreetMap file into a shapefile, but I am having problems with the "tags" field being cut-off after 80 characters. With QGIS 1.4, I use the OpenStreetMap plugin to 'Load ...
- 375
16
votes
4
answers
23k
views
Updating file locations in QGIS projects?
I have about 30 different QGIS Project files for 30 different clients. Each is saved onto my computer and all their relevant vector and raster files are all saved locally.
We are now in the process ...
- 2,575
16
votes
1
answer
12k
views
Seeking AutoTrace/Trace Tool in QGIS 3?
Have made the move to QGIS 3 but am having trouble locating the AutoTrace/Trace tool.
I have enabled advanced digitizing tools where the magnet button sat in QGIS 2.18 but it is not there in QGIS 3. ...
- 899
15
votes
4
answers
11k
views
How to efficiently access the features returned by QgsSpatialIndex?
The PyQGIS Cookbook explains how to set up the spatial index but it only explains half of its usage:
create spatial index — the following code creates an empty index
index = QgsSpatialIndex()
add ...
- 84.1k
15
votes
4
answers
11k
views
Select features from different vector layers at once?
I have two vector files in the layers panel in QGIS (V2.8.2, Wien).
I am trying to select points from both vector files simultaneously to view in both attribute tables - both tables are set to show ...
- 151
15
votes
1
answer
4k
views
Method to shade or overlay a raster map to reflect time of day and ambient light
I have a daytime raster of my study area.
I have 20+ counters in the study area that count "stuff" with a timestamp.
Using PyEphem I determined the type of ambient light for each collected data point.
...
- 8,563
15
votes
4
answers
4k
views
Rendering dashed lines between adjacent polygons correctly in QGIS
I have adjacent polygons that I want to be marked out with dashed or dotted lines. This sometimes works but there appears to be a problem where the pattern isn't always synchronised on the shared ...
- 213
15
votes
3
answers
8k
views
Setting transparency per polygon in shapefile in QGIS
How to set transparency per polygon in a shapefile in QGIS?
For example a polygon with field "value" = 1 should be fully transparent whereas field with field "value" = 0.4 should ...
- 3,285
15
votes
1
answer
34k
views
Manually editing point coordinates in QGIS
Is there a tool for shapefiles or a QGIS Plugin available, which will enable me to edit the coords of a point manually ?
("tool" -f1 "Tsunami Gauge"-move x1.abcdef -to x2.ghijkl)
...
- 850
15
votes
1
answer
9k
views
Adding labels outside of features
I'm trying to achieve this kind of labeling using QGIS. Apparently, it doesn't seem to be easily supported. Would you have an idea for a workaround ?
I managed to have circled text using "...
- 455
15
votes
3
answers
4k
views
How to create vertical labels in QGIS?
How to create vertical labels (each label in new line) like:
1998
150
pipe name
and not horizontal:
1998 150 pipe name
- 199
15
votes
1
answer
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views
How to setup QGIS Master and Stable in parallel on one Linux system?
I mainly use the QGis Master (nightly build) for my Debian Linux and I'm quite happy with it. But for educational and demonstration purposes, I now have to work with the Stable(1.8) version.
How can ...
- 8,150
14
votes
6
answers
15k
views
Renaming Shapefiles in QGIS?
I have a huge list of layers in a project that are named in a foreign language. I want to translate and add the English title to the name.
When I right click on a layer and choose Properties -> ...
- 645
14
votes
2
answers
11k
views
Choosing to use QGIS LTR or another version/release type
I am after some advice with respect to the QGIS LTR schedule.
Our IT managers have recently intervened in our use of QGIS (a State Government Authority) and are wanting to put in place a policy to ...
- 591
14
votes
4
answers
2k
views
Saving Equations used in QGIS Field Calculator?
Im trying to calculate certain values of a newly calculated point. So I use the field calculator to write an equation to determine the values.
Is there a way to save that equation, so that if and ...
- 211
14
votes
2
answers
48k
views
How to select a multiple field value by expression from the same layer in QGIS?
Using QGIS in the operation 'select by expression' how is the correct expression to select multiple field value? ex. City NAME = ROME and NAPLES (expression is invalid)
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votes
3
answers
23k
views
How to create an "area of interest" polygon mask?
I've created a GP tool using ArcGIS that creates an "area of interest" mask from selected features. Effectively it creates a new donut polygon layer where the hole was the previously selected ...
- 23.1k
14
votes
3
answers
2k
views
Creating "oblique bounding box" with maximum width/height ratio?
I would like to create a surrounding rectangle with maxiumum width/height ratio ("oblique bounding box") from a set of input features as shown in the image below:
E.g. the PostGIS functions ...
- 14.6k
14
votes
1
answer
36k
views
How to change the type of a column of an attribute table in QGIS? [duplicate]
So I want to change one of the columns in my table from string to real. How am I supposed to do that?
- 429