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

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2answers
93 views

Importing DWF files into QGIS

I regularly receive files from a service authority in DWF format, which shows the location of their assets in there area. I note that there is no option to have the data in an alternate format as it ...
1
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1answer
26 views

How to save multiple layers from QGIS to a Spatialite db?

I thought I had asked this before but I can't find any trace of it. Each time I save a layer from QGIS as a spatialite it insists on creating a new db ( if you select a existing db you are asked ...
2
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1answer
29 views

SVG Issues in QGIS API

I'm using QGIS-2.4.0 to developing an application. I created my own custom MapCanvasItem for showing SVG. It is great to load a SVG from symbol library that QGIS provides(such as d:\QGIS ...
3
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0answers
13 views

Why are my calls to SAGA routines in QGIS not working cross platform?

The ability to write and run cross platform scripts for QGIS using python is OUTSTANDING! However, when I try to run the SAGA:MERGESHAPESLAYERS algorithm from a python script it works fine in windows ...
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0answers
10 views

How to draw a perfect circle with a set radius in meters on map?

Following this istructions on how to draw a circle I can make buffer layer on each point I need. I am not able to draw perfects circle because the buffer will be elliptic? And I am not able to set ...
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0answers
7 views

Open a *.qgs project file in API, why maps do not show?

I'm using QGIS-2.4.0 API. I saved a test.qgs file in QGIS Desktop, in this project, there is one layer that is visible in it. Then I open the test.qgs project file in QGIS API to developing an App, ...
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2answers
114 views
+250

Zigzag Line Symbol in QGIS

I'm looking for a zigzag line symbol in QGIS. Is there perhaps an easy way to do this that I'm missing? I have tried creating a marker line using a simple triangle marker (^) and adjusting the size of ...
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1answer
22 views

How to load territorial maps on QGIS from web?

Is it possible to use QGIS like Google Earth? I need to draw simple shapes on territorial maps. I would like to do that without using multiple files for each part of the Earth. I use QGIS 1.8, but I ...
2
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2answers
113 views

Auto fill second column with predefined names depending on first column (QGIS)

I want to create a point layer. In the attribute table I want to have two columns. In the first column I want to type an abbreviation like A. Then I want the second column to be auto filled with ...
5
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0answers
34 views

How to produce high-resolution DEMs from new Sentinel-1 data?

This is a general question relating to the new Sentinel-1 data. I'm interested in the potential for using this data to create high resolution DEMs in GIS (I use QGIS), to investigate archaeological ...
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1answer
151 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 ...
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1answer
114 views

QGIS Print Composer with ESPG:32615

I have imported a PostGIS layer as the only object into my project and set the project and layer CRS to EPSG:32615 (UTM Zone 15N). My layer appears just fine in the work area. When I try to create a ...
5
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1answer
126 views

fTools “Join Attributes by Location” missing in SEXTANTE/Processing Toolbox

I am working with the new Processing Framework in QGIS 2.0.1. I really like the graphical modeler, because it allows my to make my own tools without having to be able to write pyhton or any other ...
1
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1answer
23 views

QGIS: How to get Symbols saved in GPX Files

I have some waypoint layers that contain different types of points and I distinguish these in QGIS by different symbols and colours. I want to export these to a GPX file that I can download to my GPS ...
2
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0answers
22 views

Assigning Color Ramp using PyQGIS

According to the PyQGIS Cookbook, a color ramp can be assigned in the following way: rlayer.setColorShadingAlgorithm(QgsRasterLayer.ColorRampShader) lst = [ QgsColorRampShader.ColorRampItem(0, ...
2
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0answers
38 views

Issue with dissolving a polygons layer in QGIS 2.4

I downloaded a dataset of roads and parks from OSM. I then buffered the roads and merged with the parks. Now - all i want is to dissolve / union all the features in the merged layer. I fail to do it ...
0
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1answer
140 views

How to solve sqlite_rtree_geometry_callback error?

I have just installed qgis 1.8 and it show error message the procedure entry point sqlite3_rtree_geometry_callback could not be located in the dynamic link library sqlite3.dll How to fix ...
0
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1answer
51 views

Creating Map from database

I'd like some general advice on creating dynamic maps. I have a bunch of geospatial points saved on SQL Server and PostgreSQL. People will enter new data into the databases from time to time. I want ...
1
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1answer
25 views

Convert From Northing/Eastings to Latitude/Longitude with QGIS

How can I convert a file with the projection below (NAD83) to one with Latitude and Longitude? The import file is a SHP file and I would like to export back out a SHP file. +proj=tmerc +lat_0=0 ...
5
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2answers
379 views

How to write scripts that can call on both Arcpy and PyQGIS?

I have spent quite a bit of time looking for a clear answer this topic and have still been unable to really accomplish my goal of accessing PyQGIS in a stand alone script. Parts of answers have been ...
1
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1answer
148 views

query / filter on attribute tables with external tables joined

i tried to do some queries on joiend table fields ... i've got/found some answers concerning version 1.8 - which result in "use select + export to create a combined dataset" so i just did some tests ...
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0answers
19 views

How to move to the next feature in the polygon with user keyboard inputs

I am new to this qgis i have one question. There is one rectangle and it is divided into some 20 grids.I wrote a program to zoom into the each feature.but if i am in one feature i want to move to the ...
2
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2answers
43 views

Printing A3 format map

I have a question about printing A3 map from QGIS. I'm going to make A3 map of one country and nearby countries, digitalise borders etc. I want to save it to A3 format, but I have only A4 printer, ...
1
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1answer
32 views

Open Source solution to batch process shortest distance between points along road networks?

I have the locations geocoded (a fairly small dataset, ~200), but I haven't found a straightforward way to load these data into QGIS and perform network analysis between nodes. Any suggestions? ...
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1answer
168 views

Floating point calculations in QGIS

How do I manage floating point calculations in QGIS? I have carried out 3 consecutive calculations on landsat bands. I end up with 32 bit floating point rasters on which I can't carry out a 4th ...
5
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1answer
237 views

QGis 1.8 fails to rotate point geometries with rule-based style

I have to do some visualizations in QGIS (1.8.0) and up to now I've been very happy with the new Dialog "Layer Properties -> Style", using the rotation-field to rotate Point-Geometries visualized by a ...
0
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1answer
194 views

visualize bounding box to a polygon

I try to make plugin in QGIS that compare 2 bounding box data, ex: (-32.61442167739459, -32.017601026186576, 13.015663782506067, 13.428145228091406) and (-38.6102467739459, -38.017601026186576, ...
2
votes
3answers
232 views

Draw line between points from multiple datasets

I have 2 point datasets and want a tool or script to draw a line between all points in one dataset to all the points in the 2nd dataset. Is it possible? I have tried ESRI "Point Distance" and ...
1
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2answers
36 views

Contour of single feature on QGIS

I'm trying to extract one single contour line at given elevation from a DEM. Taking into account that I want only one contour and not all contours with the given elevation, is there a way to do it in ...
1
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1answer
25 views

Pattern Effect in Pie Charts in QGIS?

I have more than 3 attributes to add to pie charts in QGIS, so I need a patterned fill e.g.dots, lines. Using a grey scale gives white, black and grey but using different shades of grey doesn't work ...
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0answers
11 views

Print with different settings of layer view?

Using QGIS is it possible to print on the same paper two windows with different settings of layer? I mean: window1: layer1 ON - layer2 OFF window2: layer1 OFF - layer2 ON
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1answer
100 views

autocad-map of real estates with own coordinate system and information to be converted to use it in QGIS

I have a question regarding CAD and QGIS, but unfortunately I don't have a clue of CAD. Here it goes: Real estates data has been mapped. There are several reference points surrounding the area. So ...
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2answers
88 views

render geotiff tiles as a map layer

i have the following problem: i have downloaded tiff files with gMapMaker and transformed them to GeoTiff using the associated .map files in QGIS. now i want to render these GeoTiff files to use them ...
1
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1answer
26 views

How do you extract the data behind a raster histogram

Bit of a newbie, so this may be a daft question. I have an .ecw picture - it is has no CRS, as it is a picture taken at ground level with an NIR camera. It was originally converted from a RAW image. ...
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0answers
14 views

Unable to use r.mapcalculator on r.watershed output

I want to create a new raster based on another raster (flow_acc) and a simple rule (if flow_acc>5000, 1, 0). I calculated flow_acc using the r.watershed grass tool (is the output of number of cells ...
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0answers
21 views

Raster calculation with string in modeler

In my model I have one raster file and also a string input (factor for further calculation). I tried to use the grass r.mapcalculator where I can find the raster and also the string input. I tried to ...
3
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1answer
83 views

Automated removal of dangles / loose ends in line with QGIS?

Here's what I want to do: The original line is a dissolved osm extract of ways, which I want to simplify to one continous line without dangles / loose ends (red x's in picture). I found the ...
1
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1answer
18 views

Problem by changing the order of Layers in QGis Layer Tree

I'm using QGis 2.4 on a virtual machine (Ubuntu 14.4 with XFCE). I'm connected to the VM via vncviewer, what works pretty well. But now I want to add some more layers to an existing QGis Project. ...
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1answer
50 views

Can't transform lines to polygons

I have a similar question to: How to join lines in QGIS for later using "lines to poly"? I have a line shapefile that I wish to transform into a polygon shapefile. After making some ...
4
votes
1answer
127 views

Calculating a Unique ID on a Subgroup of Polygons

I would like to assign a unique ID to polygons in a dataset. The catch to my issue is that I would like polygons that fall within a polygon to have the same unique ID. My example is related to ...
1
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1answer
28 views

How to programmatically create nested layer groups?

Using PyQGIS via the QGIS 2.4.0 Python console and the editor, I can create parallel groups for storing some layers with: MyFirstGroup = iface.legendInterface().addGroup('Group No. 1') MySecondGroup ...
0
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0answers
32 views

geometric functions in field calculator in QGIS

I had a look in the manual of QGIS and I also browse in the Internet to find some useful information about the geometric functions of the field calculator. I've found this this post but I'm still ...
3
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1answer
183 views

Calculating Topographic Exposure with Raster Calculator

I need you help trying to calculate Topographic Exposure (TOPEX) on a DEM in ArcGIS. I am trying to figure out wind exposure on a DEM with 25m cells. There is a great blog post where someone explains ...
2
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2answers
104 views

Why does QgsSpatialIndex::nearestNeighbor(point, 1) sometimes return 2 lines?

I'm trying to get the closest line to a point using pyQgis in a plugin. The active code file is this: http://pastebin.com/TDzmsKVM When I request the closest line (only 1) nearestIds = ...
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0answers
31 views

How can I get a .asc file to load into QGIS?

I got some files from an ag plane that are in ASCII format. I can not seem to be able to get them to load into QGIS without the This is a link to the file I am trying to use. ...
2
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0answers
21 views

infer the altitude from a DTM & finally provide it to point / evincere la altitudine da un DTM & finalmente fornirla a dei punti

I would like to complete a point vector's table with Z data. I am not able to take Z coordinate from a dtm (downloaded from ...
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0answers
28 views

Generating Heat Maps with GeoHash

I have a long list of GeoHash codes for a certain geographic region. I'm using 6-character precision so for example if the area under study was Earl's Court in London, I would have a few six letter ...
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1answer
38 views

How to create a Processing script using the shortest path algorithm?

I'm currently using the Road Graph plugin to find the shortest path in a road network - however, I'd like to put this to a processing script (to be used in a model later) and the Road Graph Plugin has ...
2
votes
1answer
60 views

Is there an equivalent of ArcGIS Hyperlink script editor in QGIS?

I am trying to find similar functionality in QGIS to ArcGIS Hyperlink script editor. In ArcGIS I can parse VBScript from a selected field in an attribute table. The script would execute on mouse ...
2
votes
1answer
75 views

How to measure distance between points based on elevation?

I need to be able to measure distances between points, however the distance need to be calculated in relations to elevation. The points are homes of storytellers from the 19th century and the places ...