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

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100 views

Calling QgsProjectionSelector from QGIS Python plugin?

I am trying to create a dialog that allows the user to select a coordinate system from either the recently used projections or a general list of all available projections. This would basically offer ...
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1answer
235 views

Finding left and right side of line in arcgis

i have road layer as line and polygon layer as building,i want to know left and right side of road in relation with buildings is it possible in Qgis or Arcgis?
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1answer
511 views

Creating new lines along specifically selected existing lines using QGIS?

I have tried to find a solution for this everywhere, with no result... My problem is that I want to be able to manually draw a line that automatically snaps to a line (creating an exact copy of the ...
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1answer
122 views

Switch line direction for PostGIS-lines in QGIS or Pgadmin

I am trying to switch the line direction in a PostGIS-layer. The postgis-geometry column is e.g. "LINESTRING(0 0, 1 1, 2 1, 2 2)". The reason is that my symbology is direction-dependent, but I drew ...
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0answers
100 views

Determine Transect line to cover area

I'm near certain this is a solved problem, but I haven't been able to find a solution from searches so here's my situation (probably I'm searching the wrong thing)... I need to compute the ...
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0answers
37 views

Using QgsSpatialIndex for spatial join

I've written a bit of code to do a simple spatial join in QGIS 2 and 2.2 (points that lie within a buffer to take attribute of the buffer). However, I'd like to employ a QgsSpatialIndex in order to ...
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0answers
510 views

QVariant is not defined when using addAttributes [closed]

When I try to add a field programmatically with the following code: import os.path from PyQt4 import QtGui, QtCore legend = qgis.utils.iface.legendInterface() allLayers = legend.layers() for i in ...
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2answers
926 views

How to clip a lines vector layer to a polygon layer in QGIS?

I've perused through previous questions and haven't been able to find an appropriate solution to my problem yet, so I wanted to post here. I have a lines layer (a contour map of mean annual ...
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0answers
2k views

Can someone explain to me what the “mini dump” error mean in QGIS?

I am struggling to understand what the error "Crash dumped: mini dump written to C:" means in QGIS. I am working with layers stored on a network drive. Whenever I try to read in a few particular .asc ...
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1answer
45 views

qgis2 composer - non-rectangular inset map?

I'd like to have a near-full-page rectangular map object, then add a non-rectangular inset map object with 6 vertices. Any suggestions on how to accomplish this, other than making two actual maps ...
3
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2answers
409 views

copy/paste style to multiple layers in qgis 2.2

I have many shapefiles in QGIS. How can I paste the style of one layer to all the other ones? So a "batch" copy and paste solution. If I make a multiple selection the the paste style option is not ...
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0answers
1k views

How to access a .mdb file (Microsoft Access) in Qgis (with windows 7)?

I've a very big problem. I need to connect shapes from a polygon layer with a .mdb file (built by Microsoft Access) in Qgis 1.8 (with windows 7), but I can't access it. Can anyone give me some help?
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1answer
346 views

Openlayer plugin in QGIS, error in projection 3857 Pseudomercator

I'm using QGIS plugin Openlayer to set the background of Google satellite under my vector layer. However, even if I project my layers as EPSG 3857 (the default and only possible projection for ...
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1answer
96 views

QGIS 2.2 curved labels - 'maximum angle between curved characters' makes label invisible

When labeling a curved line in QGIS 2.2, and setting Placement to 'Curved', the behavior of 'maximum angle between curved characters' is not intuitive, and I haven't been able to find documentation on ...
2
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1answer
171 views

QGIS Digitizing in Cartesian

I have a client, that needs some geological maps digitized (polygons) in a Cartesian grid. It would be a basic, square grid with North up, and coordinates in x and y. Some of the maps will need to ...
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1answer
304 views

Help defining custom CRS in QGIS 2.2

I'm trying to use EPSG:4479 in QGIS. 1) If I search for EPSG:4479, it returns a "Imported from GDAL" EPSG:4479, but it does not work. At the console, the following message is displayed: ERROR 6: ...
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1answer
224 views

Accessing CRS info with pyqgis in a standalone application

I'm currently having trouble accessing and defining CRS information in a standalone application. I've read the API documentation and have tried it in the python console in QGIS 2.2.0. The python ...
4
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2answers
147 views

Alternative to Spatial Query on large data

I have around 110000 points data spread around the world. the shapefile size is 116 Mb. I want to select points which are inside asia. I have been using qgis but this time qgis is not being able to ...
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0answers
53 views

Error SAGA algorithms in Modeller QGIS 2.2

I am using QGIS Modeller and I try to use SAGA algorithms but it doesn't work. GRASS algorithms work just fine but SAGA doesn't. I am not sure if I have to configurate something. What is worng?
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1answer
398 views

Problems adding OSM layer

I installed OpenLayers plugin successfully in QGIS 2.2 Valmiera, but when I add OpenStreetMap layer, the following error message appear as a Python error popup window: An error has occurred while ...
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2answers
45 views

Set border symbology by bordering feature?

I'm using a US state shapefile, and I want to have different border types based on properties specific to the border, not to any state. For example, I might want the Florida-Georgia border to be ...
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2answers
286 views

From RGB raster to grayscale

I have been searching for a way to rasterize shp files (Unexpected output when using gdal_rasterize) and it worked with a little help. Now, my code is first rasterizing the largest sip file and than ...
2
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1answer
91 views

How to count the number of data points in each area in QGIS?

I have a shapefile (.shp file) which defines a large number (several thousand) separate areas. I also have an Excel spreadsheet which contains a large number of data points. Each data point consists ...
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1answer
377 views

Is it possible to use polygons to create heatmaps?

I hope I can explain my question clearly, so here it goes: I've been fiddling around with heatmaps on QGIS for a few days, but came across a small obstacle on my way. I have a dataset comprised of ...
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1answer
210 views

import parameters for r.watershed - (watershed basin analysis program) tool from grass using Qgis 2.2

I want to run this tool from Qgis 2.2 but i don't know how to use the PARAMETERS to run this tool. The red frame are the PARAMETERS I don't know. Can someone to tell me what those PARAMETERS are ...
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1answer
528 views

Finding the common borders between polygons in the same shapefile

The question is essentially the same as here, except that I want to do it in qgis. Thus, is there a qgis function equivalent to the ArcMap intersect function that will take a polygon layer and output ...
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0answers
56 views

Long Time for conversion raster file to vector in QGIS

I'm a new user of QGIS, and I'm tring to convert a .tif file in a vector. To do that I have used the "Raster conversion" option, but it's taking long time. I'm waiting for the conversion since 20 ...
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1answer
274 views

syntax error when using gdal in python console QGIS

When I run the following code in the python console in QGIS I get a syntax error: import osgeo.gdal gdal_rasterize [-b 1] [-burn 255] [-a Pixelkost] [-te 170000.2 168000.27 177999.8 177999.8] ...
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1answer
90 views

Generating buffers in a automate way

I would like to creat buffers in a automate form and no matter the way (e.g. script, batches and etc) I am asking if anybody here knows how to do it or if are there scripts ready to do it. My ...
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1answer
194 views

Does QGIS Recognize Annotation Feature Classes from File Geodatabase?

My work has recently set up QGIS to access an Esri file geodatabase on a shared drive for my co-workers. I have not used QGIS much, but I have encountered an issue where the annotation feature ...
3
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1answer
157 views

How to bring feature selection into Printing Composer?

I'd like to make maps of Finland's municipalities. Our National Land Survey provides data I can make into a Shapefile, and when a municipality is selected in QGIS/Identify Features, three different ...
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2answers
87 views

It is possible to make snap using Google Maps based on QGIS?

Vectorized few lines using QGIS with Google Maps as a base. If I do not Trabachar with maximum zoom does not respect the topology of the base. It is possible to make snap using Google Maps based on ...
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3answers
70 views

Colorizing raster in QGIS 2.2 without using OSGeo4W command line?

Total beginner in QGIS. Following this guide right now: https://www.e-education.psu.edu/geog585/node/695 At step 4 I created the simple txt file which I now need to use to colorize the raster ...
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1answer
140 views

Can not load a WMS services on QGIS

Trying to load the service http://gis.ktimanet.gr/wms/ktbasemap/default.aspx and receives the message Could not understand the response. The wms provider said: Could not get WMS capabilities: error ...
0
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1answer
108 views

hint to create trekking maps with QGIS

I have a lot of different data (rivers, streets, hiking routes, bike routes,etc..) as shapefiles and some raster data (DEM). I want to create a map, that looks like a hiking map (here is an example ...
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0answers
105 views

How to split an oblong, irregular polygon layer into even pieces?

I have a polygon layer (landuse) that I want to split into 100 meter pieces. The polygons show landuse along a road. I want to split the polygons layer so that I can then calculate the percentage of ...
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0answers
268 views

How to fix “Raster layer: Provider is not valid” error when loading PostGIS rasters?

I compiled and installed the current QGIS master as usual and I imported some raster data into my postgres 9.3 database with postgis 2.0.2 extension. Whenever I try to import the raster data into qgis ...
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1answer
89 views

How to identify and highlight invalid geometries?

I'm am trying to clean/edit shape files that were created by algorithm in Qgis. My problem is when I try to split some polygons,they have invalid geometry. Is a way to identify these error maybe in a ...
2
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1answer
1k views

How to open a shapefile using Python in QGIS?

I have tried to open my shape files with the help of a tutorial (http://spatialgalaxy.net/2012/01/27/qgis-running-scripts-in-the-python-console/) but unfortunately I couldn't open my shapefiles for my ...
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0answers
60 views

Map tips Flashing

I am using some very basic html in a point shapefile's layer properties to display a photo. <b> [% "filename" %] <br> <img src= [% "filepath" %] /> <br> It will display ...
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0answers
87 views

can't get QgsGraphAnalyzer to work on a standalone script

I want to use QgsGraphAnalyzer.dijkstra in a standalone script. using version 1.8 I am following the guide at: http://www.qgis.org/en/docs/pyqgis_developer_cookbook/network_analysis.html Here is my ...
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0answers
220 views

Why does QGIS crash when my PostGIS table has a primary key?

Configuration: PostGIS Library: 2.0.3 GEOS: 3.3.8-CAPI-1.7.8 Proj: Rel. 4.8.0, 6 March 2012 PostgreSQL 9.2.2, compiled by VC++ build 1600, 64 bit, running on Win2012 server 64 bit QGIS 2.2.0 - 32 ...
4
votes
2answers
2k views

How to Polygonize a polyline shapefile in QGIS 2.2?

When I used QGIS 1.8, I was able to transform polyline layers to polygon layers with the Polygonizer plugin. In QGIS 2.2, this function has been subsumed into the Processing toolbox. Unfortunately, ...
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2answers
209 views

Most optimal way to create a (spatial) database for big amounts of data?

I am using QGIS, and on my way to set up a huge spatial database (geographical), where most of the data is points without geometry), along with other types of data (like lines in DXF and areas in ...
5
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2answers
592 views

Scale and Z factor have no effect on hillshade analysis in QGIS

I used an SRTM DEM to create a hillshade in QGIS 2.2.0. However, the resultant hillshade seems to be vertically exaggerated. Also, changing the settings for scale and z-factor does not have any effect ...
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1answer
645 views

Using Google Maps Offline in QGIS

I am working on a QGIS project that involves me using the Google Hybrid Map Plug-in. I am due to spend time travelling over the next few days and won't have an internet connection. I was hoping ...
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1answer
190 views

Generating points from chainage and offset

I have a polyline layer and an external csv containing road sign data. The csv has unique ID of the polyline, chainage along each unique segment and an offset. I have access to ArcGIS, MapInfo and ...
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0answers
214 views

Error “Unable to open data source” - import .shp into GRASS

I'm new to GRASS and GIS in general, so please forgive my ignorance... I have problem with loading Vector Data (.shp) into GRASS I used the following steps 1.1. and 1.2: ...
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2answers
172 views

Rendering a map in QgsComposition on Win 7 / 8 in QGIS 2.2.0 with QgsComposerMap gives blank map

I'm writing a plugin for QGIS 2.2.0 which should render a pdf file with a map and some text. The code is working under Linux (current Arch) and Windows XP, but it's not working on Windows 7 or 8. ...
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1answer
67 views

Raster data type as input in processing algorithms

Why the processing algorithms run just with input files located in QGIS desktop? Is there any way to work with directories? I am developing a plugin and I am using processing algorithms but the ...