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

learn more… | top users | synonyms (1)

6
votes
6answers
5k views

Open Source equivalent to Collector for ArcGIS to use with QGIS/PostGIS?

From my reading of the Esri web pages the Collector for ArcGIS is tightly tied to that platform. I would be delighted to learn that I am wrong about this. I have a strong interest in generic mobile ...
3
votes
1answer
15 views

QGIS create a line graph with attributes value on a section through the map

I wonder if I can make cross sections of GIS data (other than height). An example: I have a shapefile of a city with building plots and attribute values of the plot size. I want to choose a random ...
1
vote
2answers
26 views

How to use r.mapcalculator to change values within a raster cost map to negative

I have created a cost map in r.cost module in GRASS (through QGIS). This is actually a distance map from a protected area and distance from protected area has been calculated in both directions. How I ...
2
votes
2answers
185 views

QGIS installation from OSGeoW4: entry point not found in qgis_core.dll

I have installed QGIS through OSGeo4W installation. My operation system is windows 7 64x. I try to start the program QGIS Desktop from start menu this error: Do I need to do something? Installation ...
0
votes
0answers
15 views

QGIS dissolve by attribute and retain primary polygon attributes

I have a parcel shapefile. Many of the parcels have been combined over time, but the shapefile still represents the original parcel boundaries. The attribute table has a field for the original parcel ...
2
votes
1answer
61 views

Strange circles have appeared on QGIS map?

Why are circles appearing on my map? It started after using QGIS dev build 2.9 and now appears even on 2.8.1. Also I've noticed that the usual list of CRS does not appear while using the dev build. ...
1
vote
0answers
86 views

Processing LAS dataset in QGIS 2.8.2

I need to extract DEM from LIDAR dataset in QGIS 2.8.2. I have installed LAS tools in QGIS. I cannot configure my LAStools because I do not get Processing-->Options and Configuration and instead I get ...
2
votes
1answer
26 views

How to count points within the current Print composer atlas feature in QGIS 2.8?

In the print composer when generating an atlas, does anyone know how to show he feature count per each atlas coverage feature? For example, I have generated an atlas where each map is a different ...
1
vote
0answers
11 views

Error: Algorithm not found (QGIS)

I wrote the following code using QGIS'API. import os from qgis.core import * import qgis.utils prefix_path = os.environ['QGIS_PREFIX_PATH'] QgsApplication.setPrefixPath(prefix_path, True) ...
2
votes
0answers
43 views

Remove multiple fields from multiple shapefiles using a python script [duplicate]

I'm using the python console of QGIS 2.8.1-Wien. I have a shapefile with many fields in the table that I want to remove them. I tried to use this geoalgoritm as: ...
1
vote
1answer
59 views

How to load an (updating) point layer from Access?

I have a database table linked to the QGIS project which contains X,Y & Z coordinate information, which I can display in the Map View window of the project, after having used the “Points Layer ...
0
votes
0answers
6 views

Loading geoserver WMS raster layer in QGIS python console

I am using the following snippet to load a raster layer deployed under wms service using geoserver, in qgis python console. I am getting False output. Any idea? registry = ...
1
vote
1answer
32 views

Why is SAGA from the Processing Plugin not recognised?

Similar to this post: SAGA algorithms don't work in QGIS 2.8 except the fact that SAGA does not appear at all in the Processing Toolbox: As a check, I used the Python Console with the following ...
1
vote
0answers
9 views

PyQGIS Standalone Crashes python.exe when zooming out too far / Process finished with exit code -1073741819 (0xC0000005)

I have the following PyQGIS Standalone App which is working fine so far. One little problem is that if I zoom out to the MaxExtent(by scrolling the mousewheel) the app crashes python.exe so that the ...
6
votes
2answers
220 views

How to sample a 3D raster along a 3D path (or 4D raster along 4D path)?

I have a 3d raster dataset of atmospheric variables (lat x lon x altitude). I would like to sample this raster dataset along a 3d path. Any idea how I can achieve this, preferable with qgis or ...
1
vote
1answer
12 views

gsb projection file for qgis under MAC OSX

I'm trying to create a new projection inside wgis. The projection includes a gsb file. With the Windows OS is easy to implemnet that: you just need to place the gsb file inside the ...
1
vote
0answers
17 views

Easy Custom Labeling tool: How do I remove label arrows?

I am labeling a lot of features and the Easy Custom Labeling tool is helping me to move every label to the desired position. I also like that the tool adds arrows for labels that I moved but sometimes ...
4
votes
3answers
1k views

Edit Toolbar Became Disabled While Editing in QGIS

My edit toolbar became disabled while I was editing a layer in QGIS. I have closed the window and opened it again to edit, but it is still disabled.
2
votes
1answer
185 views

qgis missing menu bar ver 1.8.0-lisboa on ubuntu linux [on hold]

QGIS emits the following warnings when starting, and fails to display the main menu bar. $ qgis --nocustomization Warning: loading of qgis translation failed [/usr/share/qgis/i18n//qgis_en_US] ...
1
vote
1answer
60 views

How to show a QGis map in Qt/C++ custom widget with QgsMapCanvas?

I'm trying to add a QGis map in Qt/C++ widget using QgsMapCanvas, but I have some problems... I'm working with the following environment: - Ubuntu 12.04 - QGis 2.8.1 - Qt Creator 2.4.1 (based on Qt ...
1
vote
0answers
14 views

Can you load WFS uncached in QGIS

I think this might be a bug, but we've just installed QGIS 2.10 and the WFS seems to be working strangely. When you load a WFS which is not cached the system loads all the visible features as ...
1
vote
1answer
44 views

“Browse” button returns python error in QGIS

I use the latest version of QGIS (2.8.2) in MAC and have se the default Python version 2.7. Moreover, I have installed all the required python modules and GDAL. It was working before, but now, when I ...
2
votes
1answer
25 views

How to add a message bar to custom canvas?

There is a simple code to add message bar to main window in QGIS: iface.messageBar().pushMessage("Hello","World") My question is how to add bar to my custom canvas canvas = QgsMapCanvas() in ...
1
vote
1answer
244 views

How to generate random points with minimum distances between points in multiple polygons

I am looking to create random points for a random stratified survey. There are three different categories being surveyed; for each, I have a single shapefile, each containing a number of polygons. I ...
2
votes
2answers
61 views

QGIS/Python script to generate random points many times

Good day. Can anybody provide a simple code to be run in the Python Console of QGIS (I am using 1.8 Lisboa) to generate X number of random points (say e.g. 5000) over a certain global shape of ...
2
votes
1answer
43 views

Put png map image as a background to draw upon

I have an image of a fiber optics network map: I want to turn this map image (without any actual GIS data) into a vector map where each point is defined by lat, long. To do this, I'm trying to ...
-1
votes
0answers
29 views

need information about openstreetmap (osm)

I am looking for information or code sample to use OSM map I am working on a project that need to read OSM and to display it I intend to use the QgsOSMDownload and more But at this time i need ...
2
votes
1answer
1k views

Saving vector layer with specific symbology using QGIS?

I am creating a polygon feature layer with soil classes in QGIS. I need to share this layer with some colleagues and I need the layer to maintain the color ramp I have created. Is there any ...
1
vote
0answers
18 views

import qgis.core problem with QgsFeature and QgsGeometry ImportError: DLL load failed: The specified procedure could not be found

I've tried several previous answers to similar questions - no luck. I've tried everything, nothing seems to work. This is the error I'm getting Traceback (most recent call last): File ...
0
votes
0answers
12 views

Qgis Time manager raster error

I would like to give a shot to the Time manager in Qgis with some raster datasets. I load 2 rasters (both single band, 32bit float). I add the first one in the Time Manager window with the start ...
0
votes
1answer
255 views

Select features from attribute table and then create a new field with the selected attribute data

I have a shape file which contains land use typology for my administrative area. I’m investigating deficiency in certain land uses and there are 2 ‘standards’ that we have to use. These standards use ...
0
votes
0answers
10 views

How to graph a line given a great distance (e.g. 100km) and the angle?

I'm new to QGIS and I'm trying to graph subduction zones and I was given the starting point (in latitude and longitude), the length (in km) and the angle (in deg). How is it graph correctly? I tried ...
1
vote
1answer
150 views

Trying to set NAD 1983 EPSG 102631 in QGIS

I was able to find the right coordinate system online NAD 1983 Alaska But now I don't know what to do. I can't find the coordinate system on QGIS. When I choose the one I think is correct it warps ...
1
vote
1answer
25 views

How to measure the distance between multiple points and multiple polygons?

I'm trying to find a quick and accuarate way to measure the distance between 3 survey sites and all the designated sites within 10km. The survey sites are on a point vector layer and the designated ...
2
votes
1answer
174 views

How to recover deleted data from an edited point layer?

As a newbie in GIS, I didn't fail to make a newbie mistake. While editing a point layer I accidentaly deleted all the introduced data. I duplicated a layer, as it was more convenient (same style and ...
2
votes
1answer
26 views

QGIS Heatmap values change when imported into ArcMap?

I am creating a heatmap layer from QGIS and importing the TIFF into ArcMap. When I import the file into ArcMap I notice that values are different. For example the max value in QGIS is 8.92454, but ...
1
vote
0answers
14 views

Normalized Difference Built Up Indice with a threshold value in QGIS modeler

I want to use the modeler in QGIS, model the NDBI with a threshold value in order to produce a binary image. positive values = 1 and negative values = 0 my question is about which tool I can use in ...
3
votes
1answer
37 views

Overlay Analysis in QGIS (or Preferably Python)

I would like to perform an overlay analysis in Python or QGIS to output a list of each shapefile that falls within certain boundaries. I have unsuccessfully tried to use the Spatial Join, Intersect, ...
1
vote
1answer
61 views

How to register “events” for linear referencing in pyqgis?

Is there an easy solution for recording events for a line crossing borders of zones in a polygon layer? I need to implement this in python using QGIS, thus pyqgis. The image attached illustrates what ...
-1
votes
1answer
31 views

Update Column in QGIS

I would like to update columns in QGIS something like making MAPINFO . Contains , is Within, intersects ) and get values ​​such as sum, avg, propsum , count Is it possible to do this with any tool in ...
2
votes
1answer
31 views

PyQGIS standalone script does not work. Error “QGraphicsScene::addItem: item has already been added to this scene”

I try to test a PyQGIS standalone script which should just show one Shapefile. Sounds pretty simple but does not work. Here is my script: from PyQt4 import * from PyQt4 import * from PyQt4.QtCore ...
0
votes
1answer
2k views

How to georeference PNG images using QGIS? [duplicate]

How can I georeference png images using QGIS, running on OSX? I've looked at ExifTool, and the plugins GeoTag and Import Photos + Photo2Shape. These tools (and other answers) as far as I can tell ...
0
votes
1answer
15 views

Semi Automated Classification plugin (QGIS) error when trying to create ROI

When I try to create a new ROI through Semi-Automated Classification plugin (SCP) for QGIS, I keep getting a message saying: "It appears that SciPy is not correctly installed. Please, see this page ...
1
vote
0answers
18 views

How to remove las2dem streaks from raster dem

I've created a series of DEM files using the las2dem tool from LAStools, however since I don't have a licensed version they have black streaks running across them. Does anyone know a good method for ...
1
vote
1answer
27 views

How to merge two lines of polygons?

In QGIS 2.6.1, I have merged two polygon shapefiles. After merge I am facing problem at boundaries.. So I thought of changing Polygon -> lines(manually deleting one of the line at boundary) ...
3
votes
1answer
192 views

In QGis, why do parts of the OpenLayers layer export in a different scale and position? [duplicate]

I have a problem printing with google satellite maps in QGIS. In the composer it's all right, but in the pdf file some portions of the image are in a different scale and in a different position. An ...
1
vote
1answer
20 views

How can I overlay city and borough names in QGIS with political boundaries?

This post is related to this one. The following images are from @Weinfried's answer. I was able to get the ITA_adm0.kmz, ITA_adm1.kmz, ITA_adm2.kmz, but not ITA_adm3.kmz, which for some reason does ...
2
votes
2answers
48 views

Problem when opening a raster layer

I am a news user with QGIS API C++. In order to feel good with it I try some little program to explore class. I have download the tutorial 4 of the QGIS and adapted it to the 2.8 version but when I ...
4
votes
0answers
80 views

Connecting Problem: ODBC versus ESRI Personal Geodatabase (*.mdb)

I try over 2 days to connect an ESRI Personal Geodatabase with QGIS 2.8.1 Here is my testing report. Testing environment: Windows 7 64-bit; MS Office 32-bit; QGIS 32-Bit 1. Step: Creating an ...
1
vote
0answers
25 views
+50

Editing data in QGIS Server via WFS in AutoCAD Map (2015)

I have a QGIS Server up and running. I can consult my layers using WMS protocol and edit them using WFS protocol in QGIS or lizmap web client for example, but I am not able to make it work in AutoCAD ...