Tagged Questions

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

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0
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0answers
9 views

Get value of clicked raster cell

When I open a raster file in QGIS (for example a GeoTiff file), I want to quickly check the value of a clicked raster cell. I found there's an 'identify' tool in the toolbar, but when I click with ...
1
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0answers
19 views

What does it mean when I get rows executed, but with no resulted table?

While applying the following tutorial: http://anitagraser.com/2011/02/09/creating-catchment-areas-with-pgrouting-and-qgis/ utilizing vector network which has been tested (and demonstrated ...
2
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0answers
37 views

How do I get rid of this thin band between raster layers created from TNM?

After hitting my head against the table for many days, I'm humbly presenting myself to the QGIS community. I downloaded 4 IMG files (1/3 arc second, elevation data) from The National Map on the USGS ...
2
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0answers
15 views

Why pgRouting GUI panel may not work in QGIS?

What could be the reason behind the mal-functionality of the pgRouting Layer GUI panel? In order to route shortest path via dijkstra function code I'm able to conduct the task using the following ...
1
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0answers
30 views

QGIS Problem in calculating the distance of points from line

I need to calculate the distance of villages ( villages as points) from a border. I have a shapefile containing the locations of villages and another one containing the border. On QGIS, I ran the ...
1
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0answers
22 views

Apply graduated symbology renderer works in Python console but not in standalone script

I use the following PyQGIS script to load a vector layer from a shapefile and apply graduated symbology to it (tried to make it as minimalistic as possible). This works well in the QGIS 2.4 Chugiak ...
1
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0answers
13 views

IDW with QGIS from a vector points file within a mask

Given two inputs: A shapefile: points A raster: mask I want to interpolate the points within the extent of the raster except the NoData pixels that i want to use as a mask. NoData pixels are the ...
2
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1answer
32 views

Which EPSG for UTM with 8 digits in QGIS

I have a UTM datasets with 8 digits, so the first digits are 32 (for UTM Zone 32N), but which EPSG should I use to get the data at the right spot in QGIS in a 6 digits system. If I want to transfer ...
1
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0answers
21 views

Creating Triangulated Irregular Network (TIN) in QGIS?

I want to create a TIN and view it in 3D in qgis. The tin am creating using interpolation plugin is a raster TIN but i want the normal TIN(vector TIN).
1
vote
1answer
26 views

Is there a QGIS theme/project selector?

I am switching from Mapinfo Pro to QGIS and have a question. In Mapinfo, I have coded a theme selector to turn on/off themes (workspaces) in a basemap, as shown below. Has anyone made a similar plugin ...
0
votes
1answer
17 views

How to create heatmaps with small radius?

I am trying to visualize a set of pois on a map with the qgis heatmap plugin. It works great with a big radius but the layer is invisible for a small one (around 100 meters). I really need a small ...
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0answers
13 views

QGIS Raster Calculator (SAGA) with 2 conditions

I want to do calculate some equation on my raster and i need to use two condition. The tool Raster Calculator from saga seem to be perfect for me but i can not use an AND for use my two condition. ...
2
votes
2answers
34 views

QGIS - Create equal length polygon along polyline

How can I create a series of polygons along a line? I need to assess the density of a number of targets along a line within a corridor. I have tried the following: creating a buffer, using the ...
3
votes
3answers
39 views

Drawing some points in QGIS 2.4 using Python

I'm new to PyQGIS so here goes: Give a new QGIS project, how can we draw some Points on the map? I tried the following but nothing showed up. Should they be placed in a Vector layer before they can ...
3
votes
0answers
17 views

Editing Cursor for GPS live tracking in QGIS 2.4

I am interested in using QGIS 2.4 for vessel navigation due to its ability to display NOAA vector charts or BSB's as well as user created shapefiles. I currently oversee a project that requires ...
4
votes
2answers
46 views

How can I modify the width and the precision of my database?

I have a database in txt format made of several columns of real numbers. Two column are integer, 17 are real (rounded to the first decimal) and 17 are real rounded to the second decimal. If I import ...
2
votes
0answers
21 views

Separated, but combined polygons - unable to split. What determines that?

In Mapinfo it works well when splitting polygons if they are physically separated(non-combined). However, occasionally when conducting "multiparts to singleparts" in QGIS, some errors occur, although ...
0
votes
1answer
28 views

Programmatically Select a CRS in QGIS 2.4 using Python

When you run the following Python code in the Python Console of QGIS 2.4, uri = "file:///C:/data.csv?type=csv&xField=lng&yField=lat&spatialIndex=no&subsetIndex=no&watchFile=no" ...
0
votes
1answer
16 views

Non-standard WMS parameters not sent in GetMap requests via QGIS?

I am coding a python plugin to QGIS that connects to the UK National Biodiversity Network (NBN) Web Mapping Service (WMS). In general, I don't have any problems doing this with the QgsRasterLayer API ...
3
votes
1answer
30 views

Error message: qgis_core.dll missing

I have a fresh install of QGIS 2.4. When trying to open a .shp file I get the error message below. I've followed their advice and have done several re-installs and also cleared all qgis files from my ...
1
vote
1answer
40 views

Gdal/QGIS resampling asc file

I have a DEM (.asc) file with a resolution of 1000 meters per pixel. Therefore the file has a lot of columns and rows. I would like to chance the resolution per pixel from 1000 to 3000 meters per ...
2
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0answers
24 views

How to make added toolbar buttons exclusive?

I've added a toolbar to the QGIS mainWindow. Also I've added some checkable buttons to the toolbar. How can i now make my checkable buttons untoggle on QGIS default toolbars' checkable buttons press ...
1
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0answers
26 views

Field Calculator QGIS: CASE WHEN [duplicate]

at first, sorry for my English. I'm using Google translator. I have a .shp file with attribute table. Like this... -- A -- -- B -- -- C -- QString Double Double Data ...
1
vote
1answer
27 views

How to find address in QGIS using openlayers plug-in?

Is possible to search for addresses using OpenLayers plugin in QGIS?
1
vote
1answer
25 views

Use QGIS plugins in custom standalone application [duplicate]

I am trying to create a QGIS custom standalone application. I want to add the Google Physical map from OpenLayers plugin to my application when it starts, but I cannot seem to be able to access ...
0
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0answers
12 views

Issues with reclassify for QGIS Saga Reclassify Grid Values tool

I am trying to reclassify a raster using the Saga Reclassify grid values tool in the QGIS Processing Toolbox, but am getting an unexpected entirely black raster. I have verified my original points and ...
1
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0answers
14 views

How to export a postgis table to a pbf file?

I need a tool like osm2po or osm2pgsql but that does the opposite thing, convert a postgis table to a pbf file. I think qgis can do this but I can't find that option.
1
vote
1answer
41 views

Show feature count of layer via Python console / PyQGIS

When working with vector layers in QGIS, I can display the feature count of a layer and, if applicable, the feature count per attribute category (e.g. when using categorized or graduated styling) via ...
0
votes
1answer
19 views

Running GRASS functions in QGIS 2.4 from python console

I am using qgis 2.4 and i am looking for the "easiest" way to execute e.g. the r.in.gdal function from the python console in qgis. Specifically for r.in.gdal, I could not found this function in ...
3
votes
0answers
21 views

Generate a series of ellipses on a line

I am trying to create a series of ellipses (mocked up in green below) of defined dimensions along a line. I have got as far as generating regularly spaced points along the line that are attributed ...
3
votes
2answers
51 views

Spatial join without operation on the variable of interest

I have a simple problem: I've got to spatially join records of an epidemic in forests to some plot coordinates I have gathered. Problem is, I cannot obtain the records for each year on each plot, I ...
2
votes
0answers
16 views

QGIS : cannot change the z-coordinate of a point shapefile using the wkb geometry format

I am using QGIS Desktop 2.5.0-Master with GDAL/OGR 1.11.0 on a windows 7. I am working on a little pyQGis script that should modify the z-coordinate of points in a vector shapefile based on a value ...
0
votes
0answers
12 views

Filter MapComposer legend to only show layers visible on the map

I have written a function in Python / PyQGIS (no standalone application, so copy/paste it to the Python console editor to run it) that takes a VectorLayer as argument, creates a MapRenderer object for ...
4
votes
1answer
48 views

Equivalent of excel Alt+Enter in attribute table?

On excel, you can do "carriage return", that is, jump a line, using Alt+enter within a cell. When I copy a cell from excel in my attribute table, this format is respected. I can find no way to write ...
1
vote
0answers
18 views

QGIS Deployment in Citrix XenApp - How to Remove Pyramids from the image “properties”

I'm working on deploying QGIS 2.4 into a XenApp 6.5 desktop environment. We've tested QGIS to see if it will run in our environment on a test server and have found that building Pyramids with Ariel ...
1
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0answers
24 views

Importing kml google earth polygons to QGIS

I've created some polygons in google earth, saved it to kml and then I loaded these files into QGIS. The problem seems to be the projection, these polygons are slightly out of the place. I've tried ...
1
vote
0answers
19 views

Issues with QGIS WFS editing/PostGIS rendering

I want to be able to view and edit spatial data within a postgis database. I have tried using a WFS with Geoserver - but constantly get 'Empty Response' error and the Network log says the request ...
3
votes
1answer
61 views

Will core functions in QGIS 2.6 exploit multi-threading?

After reading a recent post about introducing multi-threading to QGIS, I was wondering if QGIS 2.6 will include this when running various processes. I checked online and I could only find that ...
1
vote
2answers
34 views

Is it possible to export a XSD from a GML

I want to export a XSD from a GML. I already have the GML and I want to export a XSD that fits the GML For an ETL tool we've programmed, people have to deliver a GML, XML and XSD. Those people ...
0
votes
0answers
20 views

computing the volume of a cave

I did a cave survey and now I have a dxf file 3d. It's composed by 8 layers: polygonal points width contour width height contour height stations depth I would like to make a volume and change its ...
3
votes
2answers
61 views

Averaging XY data for locations in QGIS

I wanted to find out mean of the selected point using QGIS. I tried out selecting using attribute table but could not find an option for mean in field calculator. I have attached a screenshot with ...
1
vote
1answer
32 views

Use PyQGIS to import CSV and draw points using different color

A CSV file contains columns latitude, longitude and color. uri = "file:///C:/data/balls.csv?type=csv&xField=longitude&yField=latitude&spatialIndex=no&subsetIndex=no&watchFile=no" ...
2
votes
1answer
25 views

Add OpenLayers layer from QGIS's Python console?

On QGIS 2.4.0-Chugiak the Openlayers plugin is found under Web menu rather than the Plugins menu. How can you use the Python console to add a Openlayers Google Maps layer? The following code give us ...
2
votes
0answers
13 views

QGIS GRASS shell commands not working in Yosemite

First time asking a question here. Running GRASS 2.4.3 within QGIS 2.4.0 on Mac OS 10.10 Yosemite. I'm trying to run v.net.iso within the GRASS shell, but the following error is returned every time: ...
0
votes
0answers
11 views

Tracking Conversation Records using QGIS

I am working on a project that covers three small towns. I wanted to keep track of a large number of conversations I have with an equally large number of land owner. I have a GIS file set up in QGIS ...
0
votes
1answer
24 views

Integrate QGIS Server with existing Wordpress installation

How can I integrate QGIS Server with an existing worpdress installation? I have tried but cannot get capabilities to appear. Maybe something to do with Htaccess or httpd.conf but I cannot ...
-1
votes
0answers
18 views

I need to convert a kml file to a shp file without losing any attributes [duplicate]

I am unsure how to do this, I think that global mapper would do the trick but I dont has access to a supported computer. Every conversion technique I try doesnt transfer my attribute table from my ...
1
vote
1answer
20 views

QGIS 2.4: copying of points to another point layer

in QGIS 2.4 it is not possible any more to copy points of a layer into another layer - I get the message: " Fehler: Objektschreibfehler: Objekterzeugungsfehler (OGR-Fehler: Attempt to write non-point ...
0
votes
1answer
19 views

building GDAL with libKML support

I'm attempting to import a kml/kmz file generated using Google Tracks into my QGIS 2.4 system (built with GDAL 1.10). KML files currently lose all attributes, and as such I'm attempting to build GDAL ...
0
votes
0answers
20 views

QGIS web client mobile/tablet viewer

I have been looking at OL3-mobile-viewer as an option to make my maps more accessible. Unfortunately I cannot figure out what I need to change to hook it up with my existing QGIS server and ...