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

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9 views

Merging SHP lines with attribute data combined?

I have one shapefile which contains hiking routes and another shapefile which has ski routes. Sometimes they follow the exact same path. In QGIS if the lines mentioned above are in the same SHP I ...
0
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2answers
189 views

Where to find Metropolitan Statistical Area (MSA) KML data? [duplicate]

Hello GIS stackexchange, GIS is not my field, so I apologize if my question is very basic. I need this data for a odd job at work. I have been unsuccessful in finding the data from Google ...
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0answers
21 views

How to offset polyline geometries (not symbology) using QGIS?

I have a polyline layer which has a road network digitized, up the center, in both directions however the polyline are sat "one on top of the other". I can display the lines separately by ...
1
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1answer
10 views

Digitizing 2-node lines?

I tried digitizing in to a new sqlite line layer with autoincrement id ticked..... I want to create a 2-node line, but there seems to be a minimum limit of 3 nodes. Is this correct or am I doing ...
0
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0answers
15 views

Why is SAGA kriging slower in QGIS than in SAGA itself?

I'm using QGis for a while. In my opinion the SAGA kriging tool (processing tool box) is very slow. Is that an QGis issue? I tried to interpolate a point layer with 300.000 points (I know its big) and ...
1
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0answers
15 views

Processing plugin Python error on startup of QGIS 2.8.1

I've been running QGIS with no issues for several versions now, but after I upgraded to 2.8.1 Wien I had trouble running two plugins: qgis2leaf (which I believe depends on Processing) and Processing. ...
0
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1answer
28 views

Merge touching polygons with keeping their attributes

I've got a layer of polygons Although they all in the same layer, each polygon own some unique data like the date of this polygon and an amount it possess (a number). I want to join/merge all the ...
2
votes
3answers
1k views

QGIS 2.0.1 Dufour on Windows 8 64-bit: Processing toolbox always produces error saying output layers could not be opened

I have tried to use the Processing Toolbox in QGIS 2.0.1 a couple of times now (using SAGA and OTB) and in both cases the processing tools always return an error along these lines: "Problem loading ...
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0answers
17 views

install python packages for qgis? [duplicate]

I need the twisted framework (Python) for a qgis plugin on Windows 7. I installed it with the pip installer. When I want to start the plugin it doesn't find twisted. When I start a python interpreter ...
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0answers
6 views

Incomplete results from an intersection

I am trying to map the density of buildings in flood-prone areas. In order to do that, I created a grid of equal-sized squares. I want to intersect the layer of buildings with the grid so I can ...
2
votes
1answer
183 views

Why is too long connecting to Oracle Spatial database from QGIS client?

I am having trouble connecting to an Oracle Spatial data with QGIS client. I use QGIS Version 2.2 (Valmiera) to connect to a database schema in Oracle Spatial. I asked our DBA access to our database ...
5
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2answers
16k views

How to make work tablet integrated GNSS (GPS) on Windows 8 with QGIS?

I have tablet - Dell latitude 10, running Windows 8, with integrated Broadcom GNSS Receiver BCM47511 (GPS,Glonass...). Because it is integrated GPS and Windows 8, there is the "new" way of providing ...
2
votes
1answer
23 views

How to create a virtual field in QGIS by Python Console?

Is there any example about how to create virtual field and subsequently add attribute to non-virtual field without wiping out the virtual field? Both are required to be done by Python Console. Thanks ...
0
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0answers
22 views

How to remove “ERROR 1” messages from a standalone QGIS script?

I am running a standalone script for QGIS which creates a high resolution grid and clips shapefiles onto it. Works perfect if the cell width and height have a high values (in my case, >200m for both). ...
2
votes
1answer
20 views

Automatically adding Z-values from a DEM to an already created polygon

We have excavated a very large 5.000 year old fish fence, which was documented by photogrammetry, and is now being digitized. I started digitizing the orthophoto in QGIS and everything is cool. Now ...
-1
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0answers
21 views

Difference map in qgis

I have remote sensed areas of certain vegetation (of 3 different years) and produced polygon shapefiles representing those. Now i wish to show the areas between say two year ( shrinking or expanding ...
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0answers
6 views

QgsMapCanvas render is very slow

I use QgsMapCanvas in my C++ application. When I add my layers to project in QGIS (2.6.0) they are rendered quickly (I use PostGIS to store the data). But when I load the same layers in my application ...
1
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0answers
27 views

Change layer datasource in qgis project with python

I have different qgis project with some layer and their datasource like ../my_path/my_file.shp. I need to insert this shp file to a remote db. For do it i use shapefile from PGeo module and it's work ...
1
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1answer
16 views

Generate PNG/JPG maps from multiple ASCI/GeoTIFF in Python/GDAL

I need to generate maps (saved in PNG, JPG or PDF) from raster files (for each file - one map) which meets following criteria; * each map has exactly the same color pallette, so that it will be easy ...
1
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1answer
290 views

Automating the production of GPS-compatible map tiles from georeferenced raster maps

I have a set of TIFF maps that I want to load onto Garmin GPS 62s units. The maximum size for each tile on the GPS is 3Mb and less than 1 million pixels. I manually produced one tile, following this ...
1
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1answer
40 views

How to load a raster layer using PyQGIS?

I need to load a raster file from the provided file path. I wish to use it further in the Raster Calculator. I wrote a function which converts string (I assume it is a file path) to a raster object. ...
4
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1answer
486 views

How to Install QGIS 2.6 plugins offline

"Due to various IT policies at my workplace, QGIS is installed on a machine (Window 7, 64bits and QGIS 2.6) that is not connected to the internet. I wish to install a couple of QGIS plugins on this ...
22
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7answers
22k views

Removing small spaces (slivers) between polygons?

I have a set of polygons representing administrative districts. The districts were digitized by hand, and there are small spaces (slivers) between polygons where the polygons should be touching. How ...
3
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2answers
1k views

Can I fix 'qodbc3:unable to execute statement' when querying SQL Server 2008?

I was testing features of QGIS and its really cool.I tried to query each table using right click and query but I can't query sql server 2008 database : Error: An error occured when executing the ...
2
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0answers
74 views

How setup python path in my ide to recognize QGIS API

I'm using Intellij with python plugin. Classpath for python contains $QGIS/apps/qgis/python but my ide not recognize eg. QgsVectorLayer. Any additional entry is required?
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0answers
19 views

Considering “holes” in Voronoi polygon creation in QGIS?

I am trying to create voronoi polygons in QGIS that would consider "holes" in the general domain. An example would be: I actually created the Voronois in this image using QGIS through the GRASS ...
0
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0answers
10 views

QGIS modal value within distance

I have a vector layer with several values associated to each polygon. I then have a point vector layer. I want to get the mode of each value for polygons within 500 km of each point. I'm not sure how ...
1
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1answer
38 views

How do I create a spatial filter on a layer?

I have a layer that draws points in a PostgreSQL (PostGIS) database. The problem is, all points in the table are being drawn. I want to limit the points drawn to a spatial query. How do I limit the ...
5
votes
3answers
416 views

Best practice in writing automated tests for QGIS plugins

I'm looking for some best practice advice on writing automatic tests for QGIS plugins written in Python. I have written tests for Python scripts in the past using PyUnit (the unittest module), but ...
3
votes
2answers
236 views

how to load the QGIS openlayers_plugin in standalone python script (not the QGIS embedded python console)

if I try to load the openlayers plugin in a standalone application it always fails with False, although paths are set, and plugin shows available. (tested on Ubuntu 14.04, QGIS 2.4, python-2.7) ...
2
votes
1answer
37 views

QGIS plugin problem, can't reach objects in a Qt-based Stacked Widget

I am creating a plugin for QGIS but am having trouble with the Qt components. I have used Plugin Builder and Qt designer to create all necessary files for the plugin. I want to use a QStackedWidget ...
1
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1answer
57 views

How to replace characters to eliminate encoding errors?

Working with Qgis, I have a table representing streets. Attributes inlude street name, length, pavement and some others. Unfortunately, all names with ä or ö or ü display 'odd characters' like Ã1/4. ...
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2answers
37 views

Points within polygon in QGIS [duplicate]

I have a shapefile with polygons. And I have a csv file with points. Now I want to know for each point in which polygon it is situated. Every polygon has a number, so I want to create a file where you ...
1
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1answer
26 views

Clip layer with selected object from another layer in QGIS

In ArcMap, I can clip a layer with selected objects from another layer by using the editor toolbar. I want to do the same operation in QGIS. I want to create holes in the landuse layer by selecting ...
2
votes
0answers
14 views

Error using grass script v.lidar.edgedetection

I'm in trouble with the grass script v.lidar.edgedetection. When I try to filter an xyz format dsm the script starts but at the end of it an error message appears (see attached image). Somebody ...
2
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1answer
2k views

How to fix python ImportError: DLL load failed: The specified module could not be found?

During import fiona, I am getting following error. Error is different from other user so I asked this question may be it is repeated. import fiona Traceback (most recent call last): File ...
1
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1answer
187 views

How to set field values as labels in QGIS2 Print Composer

I am mapping the distribution of 325 bird species, displaying circles in the grid cells each species occurs in. The data contains as many duplicates of the NAME as there are cells in which it occurs. ...
1
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2answers
206 views

How to delete empty fields from a Shapefile with QGIS or ogr2ogr?

I have a Shapefile with a lot of empty columns but many of them are empty. Using QGIS or ogr2ogr, how do I remove all attribute columns where everything is NULL?
1
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1answer
41 views

How Does Ogr2Ogr Simplify Work?

Can someone explain how the ogr2ogr simplify works? I am trying to use raster data which has a spectral resolution of 30m. The vector file that I am trying to import into Google Fusion is large in ...
0
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0answers
22 views

QGIS disappearing coordinate locations [on hold]

I'm having issues with some plotted locations. Some of them do not show up in the map unless I zoom in. How could I fix this in order to have all my locations plotted in the map?
1
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1answer
36 views

QGIS processing script: Move points by specified distance and add segment

I try to move points (they come as WGS84, but I'm not sure if it works with unprojected CRS) by a specified distance and connect original and new point with a line segment with the below script, but ...
0
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3answers
323 views

Import DEM into PostGIS for QGIS

I'm a complete GIS newbie so sorry if I'm using the wrong terminology in searching for a solution to this... I'm trying to import a DEM into PostGIS and display it in QGIS. The data is from the EU-DEM ...
1
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2answers
55 views

How to overlay a Lat/Long CSV and NAD83 Shapefile in QGIS?

For reference I am new (as in a few hours of messing around) to GIS. I have a shape file/accompany projection files ect: CURRENT.prj CURRENT.shx CURRENT.shp CURRENT.dbf CURRENT.sbx CURRENT.sbn I ...
1
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0answers
15 views

Track administrative changes with QGIS

I use QGIS. I have two shape files with the administrative boundaries in two differnet years. These boundaries have changed: some wards (smallest administrative area) remain the same, some are newly ...
3
votes
2answers
406 views

WMS layers don't draw in QGIS or ArcMap but do in OpenLayers

WMS Map was published by myself in AutoDesk Infrastructure Map Server 2013. I can connect and load detials (properties / metadata) in QGIS Browser, ArcCatelog. I can load the wms into QGIS desktop and ...
1
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1answer
120 views

How to generate random points with minimum distances between points in multiple polygons

I am looking to create random points for a random stratified survey. There are three different categories being surveyed; for each, I have a single shapefile, each containing a number of polygons. I ...
1
vote
1answer
54 views

How to create dissolved buffers in QGIS with PostgreSQL/PostGIS?

Creating a dynamic buffer in QGIS I use the following query: CREATE VIEW buffer40units AS SELECT gid, st_buffer(geom,40)::geometry(polygon, 31492) AS geom FROM point; Now I want to dissolve ...
2
votes
1answer
146 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 ...
1
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1answer
194 views

Problem executing Mean Shift Segmentation: could not open the output layers

I have a problem executing the Mean Shift Segmentation in QGIS with Orfeo Toolbox. I put all the parameter to execute and then, nearly 5s after appear the message that SEXTANTE could not open the ...
0
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0answers
6 views

send attribute from 75,000 object polygon to 20Mil point database

I have sql server 2008 r2. I have two tables: PropertyParameters and REF_GEOID. Property Parameters has four columns: PropertyID, ParcelID, Lat, Long. REF_GEOID has two: GEOID and GEOM. GEOM is a ...