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

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557 views

How to create WKT file readable by QGIS 2.4.0

I am trying to create a well-known text (wkt) file that can be imported into QGIS ver. 2.4.0 Here's a minimal working example of the geometry I wish to represent. POLYGON((-125 52, -125 21, -98 21, ...
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19 views

How to overlay an NOAA nautical map as a layer in QGIS [duplicate]

I am new to QGIS and am doing some work for a friend. He is hoping to overlay an NOAA nautical map as a layer in QGIS. My only real experience is with ArcGIS. He is looking to do something similar ...
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2answers
227 views

QGIS - exercise data

I´m working currently through the QGIS training manual. However, the data for the spatial analysis exercise in chapter 9.4 ...
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1answer
1k views

Connecting ArcSDE to Quantum GIS for dummies?

I really have a need to be able to connect to and edit ArcSDE data in Quantum GIS. This question has been asked before and apparently is possible, but the instructions are just not specific enough ...
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40 views

pyQGIS : Way in order to know modifications?

I 'm writing a pyqgis script. I succeed in accessing gis vector data (lists) from my remote server (thanks to urllib) . I succed in displaying geometries and attributs. 1/ Now, i would like manage ...
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40 views

PostGIS query with input from point layer

I have a table of rivers in PostGIS, each river linking to its outflow. I also have a QGIS layer of some selected sources, and would like to select the entire river downwards from each source (i.e. ...
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2answers
566 views

Is it possible to embed a Qgis map with all the information I added, in my website?

I am not a cartographer or geography student. I work in a network organization for developmental policy and I need a good software which enables me to record the cities in which our members work on a ...
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2answers
397 views

Auto populate field as concatenation of other fields

I'm searching for a way to automatically combine several field values entered in the feature edit dialogue, resulting in a new column comprised of the former values. I have, say fields A, B and C ...
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1answer
82 views

How to perform a spatio-temporal query in attribute table? [duplicate]

I am not good at programming, so I would ask for your understanding concerning my question. I have an attribute table that contains five columns which are: (Date, ID, Latitude, Longitude, Rainfall). ...
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52 views

QGIS style save issues

I have a map that I want to do graduated chloropleth maps for each year over 10 years, and I would like to use the same graduations for each year. I know this was asked earlier and therefore I know ...
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1answer
144 views

How do I save as .osm in QGIS?

The directions in http://docs.qgis.org/2.2/en/docs/user_manual/osm/openstreetmap.html#saving-osm-data seem to have been written before the OSM plugin was merged into QGIS proper. I can locate no OSM ...
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473 views

Converting multipart line into single parts using QGIS?

I have a shapefile in which a bunch of the lines are multipart. Sometimes this is due to joining ways that are not quite connected (gap less than a foot of real-world distance) and sometimes the ...
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2answers
1k views

QGIS 2.4: plugin changes map tool canvas click behavior from 2.0

I had created a plugin for QGIS 2.0 to add new features more easily. It involves changing extents and updating snapping options along with triggering the default actionAddFeature(). However, I've ...
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1answer
6k views

QGIS - Create buffer in meters

I'm very new to the GIS world, so my problem could be very stupid, but I'm going to try anyway. Objective Given a list of coordinates in longitude/latitude, stored as a .csv file, I want to create a ...
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2answers
155 views

QGIS polygon centriods - How are they created?

I have been using QGIS to analyses spatial data and I created polygon centroids with the vector geometry tools. Now for a report I have to explain how these centroids were created. I have not been ...
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1answer
104 views

Opening Annotated shape files in QGIS

Ie've been given a number of files including some annotated shape files - Basically kilometre post markers and cable identification markers, to go with a polyline shape file. I was hoping that we ...
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1answer
909 views

Python support with QGIS 2.4 on Ubuntu 14.04

I recently updated my Ubuntu system to version 14.04. I added the sources and installed QGIS as per the directions on the QGIS website. Everything looks good, except for I do not have all the ...
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1answer
109 views

Problem loading the contour plugin

I have installed the contour plugin on my kubuntu 13 laptop, but when I am opening qgis (2.0.1) I get the following message: Couldn't load plugin contour due an error when calling its classFactory() ...
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2answers
280 views

How to read Oracle data with PyQGIS? (“identifier is not long” error)

Do you have any idea how load Oracle spatial data to QGIS with using the PyQGIS? Is it possible? I try: uri = QgsDataSourceURI() uri.setConnection("*host*", "1521", "*database*", "*username*", ...
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1answer
38 views

Maintaining times with points2one in QGIS?

I have a problem that might be trivial, but I really cannot find a solution! I have a csv files with several points (x,y). These points represent the position of different animals at different ...
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149 views

Converting Shapefile Elevation field to Height Field

HAve been trying to update the elevation field in my shape file (vector file *.shp) into a height field. Have tried to rasterize the shapefile then deduct the height using Raster Calculator with a ...
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1answer
197 views

QGIS: Expression WHEN property1 = 'FOO' THEN property2 = 'BAR'

Our Foundation is adding additional properties to points. If property1 = FOO , then add property2 = BAR WHEN property1 = 'FOO' THEN property2 = 'BAR' END When I run this the ...
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135 views

v.clean in QGIS Python console

I have tried to use v.clean and v.clean.advanced (by GRASS GIS) within a script in QGIS, and was not able. I followed instructions here:, but was not able to do so. I got message: "No module named ...
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1answer
450 views

QGIS Invalid object name 'geometry_columns' QODBC3:Unable to execute statement

I was using Lisboa 1.8 with SQL Express and tables with geometry. Connections were working with 1.8 and are working with ArcGIS, so I know my tables and geometry are fine. I installed 2.4 Chugiak, ...
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27 views

Why does image resolution decrease when I import an image into the georeferencer?

I'm using QGIS 1.8.0 on Windows 7. Usually the georeferencer functions very well. However, when I try to import a particular aerial photograph (in either .tif or .jpg format) the resolution of the ...
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2answers
251 views

QGIS – Raster Calculator: Using flat (no data) areas of an aspect-raster in the raster calculator

I´m playing around with the Raster tools, following more or less the qgis-tutorial but using my own data. When I calculate the aspect of a DEM, flat areas are (logically) left without data. However, ...
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1answer
73 views

Why does QGIS add decimals when a csv is saved as a shapefile?

When I save a csv as shapefile the fields with decimals are saved adding decimals, then the new table in some case has new values. Old Table (CSV) ALTURA ELI ALTURA ORT 1.94 39.6 -11.19 ...
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2answers
706 views

Cropping or removing borders (not NoData) from multiple scanned and georeferenced maps (ArcMap or QGIS)

I have several hundred scanned maps in TIFF format, each correctly georeferenced and forming a large grid of images. The problem is that the border for each map is present - a white band, with a black ...
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0answers
159 views

How do I automatically generate a spatial data catalogue from shape files and .gdbs?

I've recently inherited a whole bunch of spatial data (mostly shapefiles but some .gdbs) which relate to a bunch of different cities. I'm looking for a way to take an inventory of what data I've got ...
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656 views

Clip or Intersection tool - QGIS giving empty files [closed]

I am trying to clip an Ordnance Survey Master Map (OSMM) feature based on a polygon created for the sake of clipping which does not have any attributes, but the output is an empty file. Projection of ...
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1answer
147 views

who to contact about issues with geoserver plugin for qgis

I have a project in QGIS that I am trying to publish using GeoServer via the plugin. When I try and publish a layer I get: global name 'provider' is not defined Traceback (most recent call last): ...
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1answer
37 views

Remove specific simple markers (multiple markers for some US states that are not fully connected)

This is a follow-up of How to create a gradient color expression in data defined properties How can I remove specific centroid simple markers? For example, Florida, Kentucky, and Rhode Island all ...
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916 views

How to create a gradient color expression in data defined properties

This question is stemming from my other question on data defined attributes: How to create a gradient point on top of a shape file? Anyway, can anyone help me create an expression within the data ...
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1answer
643 views

PyQGIS: Print Composer Map with Table

I am looking for a way to print a custom feature form created in PyQt Designer for QGIS 2.4 using PyQGIS. My goal is to print/save image as the current extent of the map with the selected feature's ...
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1answer
1k views

How to determine bounding box of current qgis 'map canvas extent' from the python console

I've asked a similar question here: How to quickly calculate bounding box coordinates of a selected polygon with qgis ...regarding a quick way to determine the bounding box of a given layer. Is ...
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1answer
37 views

Is there a way to visually clip a layer in QGIS to prevent information from rendering outside the boundary?

In ArcGIS you are able to Clip to Shape, meaning you can use a shapefile to visually clip anything outside if it. This option does not physically clip anything, nor make a new shapefile. For ...
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2answers
139 views

How to create a gradient point on top of a shape file?

I am attempting to create a point that scales in relative size to a particular integer (frequency) and is gradiented to a particular integer value, and then overlay that point onto each specific ...
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1answer
404 views

How to handle “illegal data type (Float64)” error when trying to convert .tif to .bil?

Each time I try to convert (in QGIS 2.2) an elevation model from .tif to .bil format a get this error: ERROR 1: Attempt to create ESRI .hdr labelled dataset with an illegal data type (Float64). ...
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1answer
384 views

Issue using Matplotlib in QGIS

I am developing a QGIS-plugin and for graphing I want to use matplotlib, like many other QGIS -plugins. This worked fine under linux, but under windows with QGIS2.4 I am experiencing problems. I ...
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1answer
245 views

Point cloud LiDAR

I have been trying to grid a point cloud, version1.2, LiDAR datasets which are intended to be used for hydraulic simulation of flood propagation. Already, I have used Arc* to work on the traditional ...
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1answer
643 views

Raster and vector layer in the same CRS don't match

While adding multiple raster and vector layers (and setting them all in CRS WGS84) in QGIS 2.2, they don't seem to overlap. Interestingly enough, only raster files overlap between each other, the same ...
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1answer
240 views

Raster map calculation

I figured out a way to filter a raster by using the r.mapcalculator or the raster calculator. The problem is that I have to use Qgis 2.2 because some of my models doesn't work with 2.4. In 2.2 the ...
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2answers
473 views

How to update postgis layer from shapefile in QGIS?

My usual workflow with updating layer from shapefile was to: Open DB Manager; Load SHP files into QGIS; Open DB Manager; Import file (with drop option). Now my problem is that I have created ...
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2answers
629 views

Creating a DEM from CAD contour polylines

Is it at all possible generate a digital elevation model raster from CAD contour polylines with elevations? I am using straight AutoCAD 2014, not Map3D or Civil3D. I was able to bring the dxf of ...
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1answer
96 views

QGIS to solve projection mystery in Postgresql

I downloaded some data from local agency. Per QGIS 2.2, I defined the projection to 'EPSG:3587 - NAD83(NSRS2007) / Michigan Central' in postgresql (maybe ArcMap). Data is in Postgresql 9.3. I am ...
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1answer
5k views

Cut polygon shapefile by line shapefile

I have two shapefiles, a polygon shapefile (lake) and a line shapefile (boudary) I want to create a new shapefile "polygon to the north of the boundary" What tool can I use in QGIS or other free ...
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1answer
110 views

Programmatically setting ui for QGIS via setEditForm()

I've been following this thread in attempts to configure my ui preferences programmatically. I've had no issues with loading styles (which subsequently sets the custom ui if I saved it this way), but ...
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1answer
271 views

distance difference in Google Earth with exported GPX or KML compared to source shapefile

I've converted a shapefile (points) to KML with QGIS. Points in the shapefile are within 100m distance from each other. When I measure it in Google Earth, the distance changes to 80m. The same ...
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2answers
254 views

How to bulk print maps using ArcGIS or QGIS?

I have a polygon layer that I would like to print images or PDFs from in bulk as there are a large number of them. Rather than having to manually scroll and print each individual'site' in the print ...
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1answer
370 views

Translate coordinates in GeoJSON export

I am wondering if there is a way to apply a translation in coordinates for a GeoJSON export. Currently, there are negative coordinate values in my export, which I cannot have. I am trying to use ...