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

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3
votes
2answers
117 views

Why is the OSM map itself is not visible in my qgis window?

I'm new in working with QGIS. I have tried to download an OSM map of Rome and its surroundings into my QGIS. As far as I am concerned, I have followed each step which I could find on various ...
3
votes
1answer
526 views

Using Engineering symbols (*.svg) in QGIS?

QGIS looks straight forward except for the symbols or icons. I have created SVG symbols and when I place my pointer to the obvious blank areas in the symbol library a pop-up says that my symbol is ...
0
votes
0answers
42 views

Where can I find “QGIS Training Manual” data? [duplicate]

I can't find data for this lesson in Quantum GIS: 9.4 Lesson: Supplementary Exercise. Can anybody help me?
0
votes
1answer
173 views

Gdal_sieve not working?

I'm using the Sieve command within QGIS (Raster > Analysis > Sieve), but when I run the command with any variation of parameters, it completely changes the histogram of my raster data from between ...
2
votes
1answer
454 views

Best Landsat band for forest classification?

Using Qgis and the Semi-Automatic Plugin for Classification, which are the best Landsat bands to use to classify trees species (in central Argentina)? In Landsat 5, 7 and 8?
2
votes
0answers
195 views

Setting up qgis web client

I have a problem with setting up a qgis web client on remote server. I set it up on localhost and it runs smoothly, but when I done exactly the same on remote server it is just not working, even a ...
2
votes
1answer
397 views

PyQGIS - Start/Stop Editing with data Provider - Commiting changes

I want to edit a specific field for a QgsVectorLayer, within a QGIS application. I am facing inconsistent results from my code, ie: changes are not alway commited. Please could someone point me to ...
4
votes
1answer
186 views

How do you set the position of a plugin window when you start the plugin?

I'd like to set the position of a plugin's window or dialog relative to the map canvas frame. For example, if I start a plugin, I want it to appear somewhere in the left upper corner of the map ...
3
votes
0answers
318 views

How to calculate percentages using QGIS field calculator expression?

I am new to QGIS. I am wanting to calculate a field using other fields and some operators. Here is my expression: case When "RVM_CAT" = 'B' OR "RVM_CAT" = 'C' Then ("PC1" /100) * "RE_ha" When ...
1
vote
1answer
61 views

Contour generation using Interpolation - Correcting edge Effects

I utilised the Interpolation feature in QGIS to prepare contours from a DEM I had generated. Sometimes when contours intersect the edge of the DEM area, they run along the edge for some distance. ...
1
vote
1answer
352 views

How to add new columns with attributes in existing Qgis layer?

How to add new columns with attributes in existing Qgis layer? Doing the "same thing" here described
3
votes
1answer
229 views

Reverting QGIS to version 2.2 from 2.4

I have QGIS 2.4 installed on a machine running Windows 7 64-bit "by accident". I was using 2.2 and when I added some package(s) it also installed the 2.4 version. Can anyone provide some advice with ...
1
vote
0answers
234 views

OpenGeo Explorer error publishing layers to geoserver

I want to use Opengeo Explorer to publish layers to geoserver but i am getting an error report. I create workspaces with no problems and i publish styles with no problems. Can you pls help? Error ...
6
votes
1answer
396 views

Can QGIS map canvas update while python script is running?

I want to automate a periodic refresh of the QGIS map canvas with updated shapefiles. A Python plugin or console script does not allow the map to update until the script terminates. Is there a way to ...
2
votes
2answers
72 views

Help projecting Austria data with QGIS

I'm trying to reproject this dataset from Austria Statistik Geodata. Data comes in "MGI_Austria_Lambert", and I'm trying to reproject to WGS84 What I'm doing is Saving layer as... and selecting ...
2
votes
1answer
167 views

Density slice/Colour slice in QGIS?

Can you do Raster Color Slices (like in ENVI) in QGIS? I.e. Where the histogram can be divided up into discrete units to represent different classes based on the values of the pixels.
4
votes
1answer
95 views

Is there a maximum length of pdf file QGIS composer can plot?

In QGIS 2.4 is there a maximum dimension in milimeters composer can produce while exporting to pdf? Trying to produce a 3000 x 900 mm or 2800 x 900 mm map. The QGIS composer displays all the map area ...
2
votes
1answer
174 views

Python console not working at all

My python console won't work at all. I can't open it. My QGIS version is 2.4. OS is win7 64. I've reinstalled QGIS a few times but I always get the same result. Strange. Something went wrong with the ...
5
votes
1answer
290 views

Workflow for adding Pipe Systems to QGIS

I want to layout a concept design for a sewer main in QGIS. I have a variety of background information: Aerial Imagery Services from various sources DEM from LIDAR Lot Boundaries I want to ...
2
votes
1answer
746 views

Using QGIS to access data delivered by ArcGIS for Server?

Can I use QGIS to access data delivered using ArcGIS Server? The following servers don't seem to be compatible with QGIS http://www.topofthesouthmaps.co.nz ...
2
votes
1answer
222 views

QGIS 2.4 Layout View pdf/raster file export moves points

I created a map, using a google basemap (openlayer plugin) and imported a table as a csv file (containing a name of a city, latitude, longitude for wgs84 and a row named "amount"). It displays ...
1
vote
1answer
35 views

Clipping a TIGER Census Tract by Vector Outline

So I have recently downloaded the 2011 Tiger Census Tract for the 5 Boroughs of Manhattan which I would like to process for a future visualization. The Tract Shp file includes water areas, which I ...
2
votes
3answers
743 views

Rasterize line shapefile

I'm trying to convert a line shapefile to a raster image at QGis, but my attempts have been unsuccessful. I've tried to use Raster/Conversion/Rasterize and SAGA/Grid - gridding/Shapes to grid, but to ...
1
vote
0answers
82 views

How to import a map consisting of pictures

I want to built some sort of Fantasy Map with Quantum GIS. The whole map is built out of 128x128 single pictures, 16384 in total. It should be a flat map. How do I import these pictures and align ...
1
vote
0answers
138 views

Annotation/Label size adjusting to map scale in QGIS

I'm trying to label the street names for a map I'm working on but I do not want the labels to automatically adjust to the map scale when zooming in or out. My question is: In QGIS how do I set a fixed ...
1
vote
0answers
122 views

GDAL WMS in QGIS 2.4

I'm trying to add in QGIS a layer shown here : propluvia When I watch in my console I see this request corresponding to the layer I need. The server is not able to respond to a getCapabilities ...
1
vote
1answer
89 views

Why is the data missing in my new shapefile?

I've made a new shapefile from a part of an attribute table. Marked all the rows that I needed and clicked on "save selection as", added the new layer in my project. All the data is missing, there is ...
3
votes
0answers
220 views

Startup python script to re-join layers in QGIS?

In QGIS 2.2, there is a bug which involves using the JOINS properties on a vector layer (that is already being joined with several other vector layers) whereby the attributes are not fully loaded. ...
4
votes
2answers
97 views

How to show labels for all polygons in a layer, even with 'NULL' values?

I have a polygon layer which contain information on property name, number of trees within the polygon, average height, and min- and max height values. My problem is, I want to label each polygon with ...
2
votes
1answer
537 views

SPOT 2-5 convert DN to TOA using QGIS

I'm new to QGIS and I would like to convert SPOT(2-5) images from DN to TOA. How do I go about doing this? I've an idea of how to do it for Landsat images however I'm not sure about SPOT.
5
votes
2answers
633 views

pretty icons for GIS development

I am developing a GIS software and I want to build a pretty GUI for it. Where can I found some pretty icons for my GUI? I mean for example, icons for adding a vector or raster. I mean icons like QGIS ...
2
votes
0answers
55 views

Error in polygonising raster data with QGIS on Mac

I'm using QGis Chugiak on a Mac and I'm trying to converting a raster layer in a vector data by: Raster/Conversion/Polygonize. So, I select the layer needed from the drop-down menu, I give a name to ...
1
vote
1answer
164 views

QGIS: Why do I get permission denied when saving style to postgres

In QGIS I am trying to save a style to a postgres database but I always get the error "Unable to save layer style. It's not possible to insert a new record into the style table. Maybe this is due to ...
1
vote
1answer
147 views

Accessing pgsql db set in cygwin from qgis installed on windows through osgeo4w, possible?

As the title of this question, I want to know if it is possible to access a PostgreSQL database set in cygwin (version 9) from QGis installed in Windows 8.1 through the OSgeo4W application, is that ...
3
votes
1answer
638 views

Cause of ImportError: No module named mapscript in QGIS mapserver export?

I'm trying to expor project to mapfile in new QGIS Chugiak but a get this error below, someone have the same error? How can I fix this?thnks. An error has occured while executing Python code: ...
3
votes
1answer
359 views

Sorting layers in legend using python in QGIS 2.4

In QGIS 2.2 , I was able to sort in alphabetical order the layers simply using this: self.maplegendtree = iface.mainWindow().findChild(QTreeWidget, "theMapLegend") self.maplegendtree.sortItems(0, ...
3
votes
1answer
51 views

Refreshing “layer render order” widget

i made changes in the render order of my map canvas using a : qgis.utils.iface.mapCanvas().setLayerSet(a) "a" being a list of QgsMapCanvasLayer My code is working as expected (i see result on map ...
0
votes
1answer
142 views

How to upload a series of OS map sheets using QGIS and merge together?

I need to upload historic OS sheets in tiff format, and 'stitch' them together, as some districts are spread over a number of sheets. I have no idea how to do this. Can anyone help?
1
vote
0answers
26 views

Export polygon to points (vertices) [duplicate]

This is the first time that I have worked with geospatial data and QGIS, so please be kind. I was given a shape file that contains house districts for the state of FL. This link provides ...
0
votes
0answers
20 views

Where is QGIS 2.4 user guide for Esri file geodatabase? [duplicate]

I found no 2.4 user guides or documentation at qgis.org. I googled for 2.4 file geodatabase info but found nothing. Can someone point the way?
1
vote
1answer
106 views

QgsMapLayerRegistry().removeMapLayers(wfs_layer) causes crash

I have a WFS layer, served by Geoserver, loaded in QGIS using the standard 'Add WFS layer' dialog. When I try to remove it using: QgsMapLayerRegistry().instance().removeMapLayer(wfs_layer.id()) I ...
3
votes
0answers
531 views

Creating one DEM from multiple ASC files

I am struggling with this several days and now its time to ask how to do it in QGIS. I have very detailed 27 ASC grid files with overall size of 9 GB created from 1m contours of large area (600 m2). ...
1
vote
1answer
80 views

QGIS create raster from cadastre (property lot data) polygon

I have a cadastre (property lots) polygon dataset of a region. Have used rule-base style in QGIS to show different groups of properties in the dataset classified based on their property lot size (ie. ...
1
vote
2answers
2k 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
vote
1answer
75 views

How to crop a vector shapefile according to raster?

I am trying to clip a vector shapefile- points according to a DEM in QGIS. I used GDAL function and polygonized the DEM. Then I ran the Vector-Geoprocessing tools-clip in order to crop the vector data ...
1
vote
0answers
179 views

QGIS Grass Processing toolbox

I'm trying to use some of the GRASS tools from the processing toolbox in QGIS. I get the following Python error: An error has occured while executing Python code: Traceback (most recent call last): ...
3
votes
1answer
122 views

How to combine historic OS sheets in order to create density maps of historic streets

I really need some advice on creating historical street maps using GIS software (I have access to QGIS and Diva). Basically, I want to upload a number of historic OS sheets, which I have downloaded ...
2
votes
1answer
331 views

Delete duplicate polygon nodes with PostGIS

I'm trying to delete duplicate nodes from a shapefile with QGIS, but after running the tool to delete it, nothing happens and shows the same errors. I thought that maybe importing to postgis could be ...
2
votes
2answers
716 views

Open Raster stored in ESRI V10.0 Geodatabase in QGIS V2.4

Is there a way to open a raster that is stored in ESRI V10.0 Geodatabase in QGIS V2.4. I can open the vector layer, but there does not seems to be a way to open a raster.
8
votes
1answer
188 views

Can you use wildcards for column headers in Field Calculator?

I know you can use wildcards for fields like so (in the Field Calculator): case when "column" ILIKE '%example%' then 1 else 0 end Can you do something similar for the column headers themselves? I ...