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

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1answer
60 views

Polygons Shrinking and Moving as if CRS Was Suddenly Out of Sync with Project

I long ago set the CRS for a linguistic geography project I'm working on involving Oklahoma data (EPSG:2836 - NAD83(HARN) / Oklahoma North), and I have been closely monitoring that the polygon ...
6
votes
3answers
790 views

Are there open source solutions for travel demand modelling?

I'm looking for open source tools for travel demand modelling (eg The four-step UTMS). Preferably in a GIS environment. That works well with Qgis, Grass and Postgis. My question is not related to ...
4
votes
1answer
284 views

Is it possible to open the attribute table using PyQgis?

is it possible to open an attribute table from the python console or through a python script in QGIS? Thanks!
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2answers
366 views

How does MYSQL accept the WKT representation of a polygon with holes?

I have a set of coordinates that creates a polygon with holes in it. I'm using qgis with mmqgis to extract. How does MYSQL accept the WKT representation of a polygon with holes? By holes I mean ...
2
votes
1answer
92 views

Why do edits made in attribute table not show in associated layer? QGIS 1.8.0

I have compiled a heat map layer to display over a background raster map. I discovered that the heat map layer was incorrectly positioned because I had made an error in the coordinate entry fields of ...
2
votes
1answer
176 views

Which Graduated Symbology to use in QGIS

I am trying to map demographics data for a county in the UK based upon a combination of Census data. I want to compare the the averages for the county alone to the averages of the UK as a whole and ...
0
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1answer
36 views

Matching items from two tables

Can I select items in one table by matching items from a duplicate column in another table in QGIS?
1
vote
1answer
344 views

AttributeError: 'QgsFields' object has no attribute 'itervalues'

First of all, the code which is below gives me the attribute names of a shapefile correctly if I use PyScripter IDE: from qgis.core import * from qgis.gui import * from PyQt4.QtCore import * from ...
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1answer
203 views

What is required to get OGR to work with SQL Server?

All, I've been having heaps of trouble getting OGR to connect to our SQL Server development environment. (read about it here and here) SQL Versions: 2008, 2012 OS's: Windows 7, Ubuntu 12.04 My ...
4
votes
4answers
737 views

What does the “service” box in the PostGIS connection dialog stand for?

Can sоmеbody explain me what to write in the "service" box when connecting to the local DB. QGIS Lisboa and Postgres are installed.
0
votes
1answer
105 views

QGIS Value Map Edit Widget with properties dependent on another field

I'm having a problems with Edit Widgets in QGIS. I'm working on a GIS Database for archaeological data, where every site is represented by a polygon. In the attributes there is a field for the era ...
0
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1answer
79 views

How to edit a table in GRASS?

How do I edit a table in GRASS? When importing a vector into GRASS from QGIS, all the attributes are lost and I need these to continue with my analysis.
3
votes
2answers
114 views

How to avoid the CRS Dialog when creating a vector layer memory?

I am trying to create a vector memory in a plugin. Basing on some examples,I was able to create a memory vector layer and to add it in QGis with : QgsMapLayer.instance().addMapLayer(myLayer,True) But ...
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vote
2answers
381 views

How to use SEXTANTE in a script outside QGIS?

I´m trying to do some geoprocessing using the QGIS Sextante plugin outside of the QGIS application (and integrate it with different other libraries like arcpy, etc.). import sys, os from PyQt4.QtGui ...
1
vote
1answer
179 views

How to get Quantum GIS display a line or polygon feature created by Python package pyshp

I am not sure if I have discovered a regression, or if I have not enough sleep. While I manage to create shapefiles with point geometries with pyshp, line and polygon features don't show up in QGIS. ...
4
votes
3answers
2k views

How to compute flow direction and flow accumulation with Qgis?

Any one who had made flow direction and flow accumulation on raster data for filled evaluation model i Qgis? Which tool and plugins are necessary, i haven't been able to find any guidelines on Google
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0answers
102 views

How to convert a set of points to a polygon based on a specific field in QGIS

I am having a point shapefile that consists of a number of point sets. I need to convert these points to a polygon based on a particular field in attribute table say for example locality . How can i ...
0
votes
1answer
372 views

How to remove shapefile polygon vertex marker points in QGIS 1.8.0

I have created a shapefile layer and drawn a polygon to show the boundary of a woodland. How can I edit the polygon to remove the crosses that denote the intersection of two points on the boundary?
0
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1answer
209 views

Custom Form with QTDesigner: Combine signals and slots?

I dare to ask that question here and not in the programmers section, cause i'm actually not looking for a coding answer, but a solution through the QtDesigner GUI (if possible). Custom QT-forms ...
0
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1answer
272 views

how to make transparent layers with Google earth layer?

with your help, i solved most of my problems, but here is another one - i guess, a smaller issue... I managed to get Google earth layer, but when I add my GPS gpx files, are all hidden under the ...
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2answers
1k views

QGIS conversion of Microstation .DGN to .SHP?

I'm attempting to convert a .dgn file to .shp using QGIS. I'm reading that support is only provided for v7 microstation files, is this still the case? I've been using ogr2ogr -f "ESRI Shapefile" ...
3
votes
2answers
418 views

how to add orthophoto layer in qgis

I am not an advanced user, but I try to be oneday :) here is my issue: I have tracks (just waypoints) from my GPS in gpx format. I also have orthophoto pictures in tif format, that I would like to ...
0
votes
1answer
31 views

Is the Qspatialite 6.0.8 font for SQL free text supposed to be huge?

A week ago I upgraded my Qspatialite plugin in QGIS 1.8, which I frequently use in parallel with Spatialite_GUI, to get the best of both Sqlite worlds. I immediately noticed that my SQL free text ...
6
votes
3answers
2k views

How to digitize a raster automatically

I have a raster (.sid extension) file. I want to digitize roads automatically in ArcMap, QGIS..etc. Digitizing by hand would be too time consuming. How can i do this ? Thanks
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2answers
321 views

How to create a MultiLineString feature with a postgis layer in QGIS

I have troubles handling with MultiLineStrings in QGIS. I added the table where I defined a column as geometry(MultiLineString, 31468) as a postgis layer in QGIS. Now I want to create features with ...
4
votes
1answer
86 views

Automatic selection of legend object in QGIS

I'am using the Corine Land Cover data for a projet. There is around 40 types of land use in this database. In my print composer with my scale (1:20 000) I neve have more than 10 type of land use. I ...
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1answer
177 views

Is it possible to rotate annotation labels in Print Composer?

Is it possible to rotate a labels (not feature labels but manual annotations) in Print Composer in QGIS 1.8?
1
vote
1answer
68 views

How do I delete multiple data points from a .csv file through QGIS?

I have a .csv file with points in North America, but I only want to focus on a section through North America that excludes places such as Alaska and Greenland. I've selected the points below, but ...
2
votes
2answers
763 views

QGIS crashes when using dxf to shp converter

this is my first question on Stackexchange. I use a GPS to capture data in .dxf, manipulate it in a CAD program that I know how to use, then the dxf2shp converter (I think Python is mentioned) to let ...
3
votes
2answers
219 views

How to show just some labels based on feature intersection of layers?

I'm trying to use "expression based" labeling in QGIS, but I'm stuck with a particular case. I managed to use it for a project with the help of other topics and FAQ but I'm not skilled enough to ...
2
votes
1answer
216 views

Adding temporary graphic or vector layer to QGIS to replace the slow select feature method

I have a custom QGIS 1.9 dev (so 2.0 I guess) plugin which collects and displays a list of polygons in a QTreeWidget. I would like to select a list item and it immediately display a highlighted ...
0
votes
1answer
204 views

how to export mdb to dgn file in qgis

I am having an (.mdb) file .I want to export this file to (.dgn) format .How can i do this in Qgis ? Is there any plugin available ?
0
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1answer
167 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 ...
3
votes
1answer
192 views

Bar graph - cartodiagram in QGIS

Can I create a cartodiagram in QGIS 1.7.3? I need one bar graph in every territorial unit of one layer. It must vizualize organization on X and number of research in one organisation. Is it possible? ...
1
vote
1answer
193 views

QGIS Regex substring for Labelling

I'm trying to plot a series of contours in QGIS based on dxf data exported from some specialised mining software. The attirbute output is pretty ugly and merges a few fields together. DXFName=C$5 ...
1
vote
1answer
291 views

Problem loading PyQGIS

There is a problem on my system when starting QGIS. I get this error. I am running openSuse Tumbleweed 64bit and openSuse 12.3 64bit. Same problem on both systems. Couldn't load PyQGIS. Python ...
0
votes
1answer
141 views

Importing UK Land Registry data into Quantum GIS

We have purchased data from the UK Land Registry to import into Quantum GIS however when I do so using the Coordinate referencing systems of OSGB 36/ British National Grid (EPSG:27700) the data ...
1
vote
0answers
130 views

Label problem on QGIS

It's my first question here so, I hope not to be too bad at it. I'm using QGIS 1.9.0-Master on mac osx. I think I have some question and some bug issues, so also posted a message on ...
1
vote
1answer
264 views

Qgis - raster values become integer when Polygonizing

When using the GDAL plugin, "Polygonize (raster to vector)" any values in the resulting vector layer is truncated to integer. I have a raster showing windspeeds in squares of 500*500 meters, in the ...
0
votes
1answer
125 views

With QGIS, how can I create a layer from a .csv file?

I have a .csv file with ~16k points with lat and long to plot onto a map. I'm completely new to both QGIS and GIS in general and have got to a point where I have downloaded the OpenLayers and ...
1
vote
1answer
183 views

Can't view PostGIS rasters after changing schemas

I have loaded a few rasters into the Public schema of a PostGIS 2.0 database. Using the db manager in QGIS 1.8.0 I can add the rasters to the map canvas. After moving the rasters to another schema in ...
2
votes
1answer
110 views

Changing projection for field calculator

I've just succeeded in getting the area of a polygon using field calculator. The polygon was drawn on a Google hybrid aerial photo. There are no units given in the calculation and I assume the area ...
16
votes
1answer
634 views

How to create a QGIS Installer for Windows with GUI customization?

I'm trying to build a custom QGIS installer for Windows with a stripped down GUI. I customized the GUI using the customization function of QGis and saved it as a .ini file. The question now is: How ...
1
vote
1answer
159 views

Unable to create shapefile in QGIS

I am very new to QGIS and although I've been able to download the software and get aerial imagery using the plugins menu, I'm getting nowhere with creating a shapefile that I can use to draw a polygon ...
0
votes
0answers
164 views

Covisibility with QGIS/GRASS : r.los issue

I try to use r.los for a viewshed calculation. I specify the dem (Aster DEM clipped on a 2km*2km region). I specify x and y coordinates and run the command. Nothing append. I waited for 20 minutes ...
8
votes
1answer
258 views

How does Spatialite handle concurrent access?

I understand that Spatialite is meant to be used by a single user/machine at a time. However if the data is stored on server, there is no guarantee that someone on another machine will not also open ...
2
votes
1answer
150 views

Plugin error in Qgis

I just now downloaded a plugin named "XY tools"from fetch plugins option . I am a user of Qgis v 1.9.0.It shows me the following error: An error has occured while executing Python code: Traceback ...
0
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2answers
79 views

Where to find 'Identify feature' tool in QGIS?

It used to be an arrow with i. Now I have different version, I have gone through all the buttons and panels but cannot find it!
2
votes
1answer
151 views

How to reproject vector data?

I am evaluating QGIS with a view to visualize and manage geological exploration data. The information is currently stored in different local coordinate systems that I am looking to overlay with ...
0
votes
1answer
660 views

OS Vectormap GML files into PostGIS

I am having difficulty in efficiently dealing with OS Vectormap data that comes in GML format. In the past I used the Plugin for QGIS (OS GML Tools) to batch convert folders of compressed GML (.GZ) ...