Stack Overflow
Stack Overflow

Questions tagged [qgis]

QGIS is an open source program used to process and visualize geospatial data. It is available for most desktop and mobile operating systems.

QGIS (formerly Quantum GIS) is a user-friendly, cross-platform Geographic Information System (GIS) application with support for Linux, Unix, MacOS X and Windows. News updates are available from the QGIS blog.

QGIS supports numerous vector, raster, and database formats and provides numerous features for exploring, creating, analyzing, converting and exporting geospatial data. The core functions can also be extended through external plugins written in .

QGIS is an official project of the Open Source Geospatial Foundation (OSGeo) and is licensed under the GNU General Public License.

The gis.stackexchange.com site covers QGIS use cases in detail.

1691 questions
5
votes
2 answers

Adding attributes to datapoints from overlapping polygons in qgis

I have an interesting problem in QGIS, I have a vector layer of points (shown in purple) and a layer of polygons (green) with a number of metadata attributes attached (i.e. date, id number etc). I want to attach the data from the polygon to the…
ALs
  • 509
  • 2
  • 4
  • 17
5
votes
1 answer

How to perform multiprocessing for a single function in Python?

I am reading the Multiprocessing topic for Python 3 and trying to incorporate the method into my script, however I receive the following error: AttributeError: __ exit __ I use Windows 7 with an i-7 8-core processor, I have a large shapefile which…
Joseph
  • 586
  • 1
  • 13
  • 32
5
votes
2 answers

How to add characters to filename using glob in Python?

The following is a snippet of code. The script takes the input files from a "Test" folder, runs a function and then outputs the files with the same name in the "Results" folder (i.e. "Example_Layer.shp"). How could I set it so that the output file…
Joseph
  • 586
  • 1
  • 13
  • 32
5
votes
2 answers

How to merge adjactent polygons to 1 polygon and keep min/max data?

I have the following polygons in PostGIS Each polygon has field with "Data" value. I would like auto merge the polygons which touch each other : 1-2 and 3-4-5-6-7 Also , If possible I would like to have the Min/Max values from the columns of each…
Alophind
  • 842
  • 2
  • 12
  • 27
5
votes
1 answer

PostGIS: Merge Multipolygons and keeping boundaries

We are trying to merge two Multipolygons which are stored in our PostGIS 2.1 database without losing the boundaries that are contained in each Multipolygon. Our spatial data matches the following criteria. -- Check whether the polygons share points…
Cord Kaldemeyer
  • 6,405
  • 8
  • 51
  • 81
5
votes
2 answers

Setting proxy parameter in qgis plugins. How to

For those who are interested I found the definitive way to set proxy settings from within qgis plugin in a user-transparent way. This is useful if you plan to use webservices with urllib or QwebWiew. Using Qsetting function is possible to read and…
Enrico Ferreguti
  • 438
  • 4
  • 13
5
votes
1 answer

sudo easy_install bsddb3 error :Can't find a local Berkeley DB installation

I tried to make a plugin on qgis with Python 2.7.3 and there is a error happend and I find a way to install bsddb3 to replace bsddb but when I try $sudo easy_install bsddb3 it's give me a error Can't find a local Berkeley DB installation I have…
blueman010112
  • 456
  • 1
  • 7
  • 19
5
votes
3 answers

Can python read the value of a cell in a spreadsheet?

All, Can python read the value of a cell in a spreadsheet? From a mapping/GIS/analysis standpoint: the simplest example would be a script that ran a buffer (proximity) tool on a given shapefile (GIS dataset). For the buffer distance parameter,…
DPSSpatial
  • 767
  • 3
  • 11
  • 31
5
votes
1 answer

build a road network

I have various number of tracks which represents different roads. Each track represent one road. I have loaded this gpx file into my postgres. Now my problem is how am I going to build a network between all these roads, in order to be possible to…
IT_info
  • 707
  • 4
  • 16
  • 36
4
votes
2 answers

Plot a geographical map with symbols according to frequencies

I would like to plot a geographical map with n numbers of squares according to the frequency of a disease within a county. Like this one here: But I couldn't figure out how to do this with R or qGIS. Thanks for y'all help.
Dominik
  • 2,753
  • 7
  • 28
  • 32
4
votes
2 answers

How can I obtain the coordinates/extent from a geospatial PDF?

I have a geospatial PDF exported by QGIS with a raster inside, I need to read this raster to create a XYZ tiles structure, and for that it's necessary to get file's coordinates/extent, but I can't extract this information from the PDF or even the…
Gabi Vieira
  • 371
  • 2
  • 13
4
votes
1 answer

QGIS - Hide some Symbols in a Shapelayer depending of the viewfield

How is it possible to hide some of the symbols, depending on the viewfield and zoom ? I use the Rule-Based style to assign the colors and the direction of the arrows. How it looks in qgis: Layer in QGIS How it should looks like from qrcgis Layer in…
Kai_himself
  • 41
  • 3
4
votes
1 answer

QGIS edit turning POLYGON into MULTISURFACE

I have a PostGIS table with POLYGONs that I need to do some cleanup editing on in QGIS. However even a simple edit like deleting a vertex is saving the result back as a MULTISURFACE. I am using QGIS 3.16. How do I instruct QGIS to use the simplest…
Derek
  • 345
  • 3
  • 15
4
votes
2 answers

Cut NetCDF files by shapefile

I have a large dataset of global .nc files and I am trying to clip them to a smaller area. I have this area stored as a .shp file. I have tried using gdal from Qgis but needs to do this by converting each variable and I must select each variable and…
Sabina Hurtado
  • 41
  • 1
  • 2
4
votes
2 answers

CMake compilation error..(Unknown CMake command "QT4_WRAP_UI")

im trying to build grass plugin for qgis .. when i try to use cmake .. i get the following error after configuring.. CMake Error at CMakeLists.txt:78 (QT4_WRAP_UI): Unknown CMake command "QT4_WRAP_UI". I have Qt4 ,PyQt and python2.6 installed…
ashishsony
  • 2,537
  • 3
  • 26
  • 38
1 2
3
…
99 100