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

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79 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 ...
4
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1answer
92 views

Finding maximum radius of circle within irregular polygon without using ArcGIS Spatial Analyst?

I have a problem which I think could be handled by using the toolset "zonal" / zonal geometry in the ArcGIS Spatial Analyst toolbox. However, I do not have a license for Spatial Analyst, so I am ...
3
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1answer
39 views

How to filter QGIS layer from python?

Using QGIS 2.4 python console, I'm trying to display only a subset of a layer features. I've managed to get the features both from the layer : featuresIterator = ...
3
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1answer
23 views

Control points display location changes with scale

I'm trying to georeference an image by choosing points from Map (imported from Google hybrid) however the resulting tif is in no way located similar to the points (in fact the control points don't ...
2
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2answers
58 views

Cannot Install QGIS Mapserver On Ubuntu 12.04

I'm trying to install qgis-mapserver on my ubuntu 12.04. I just installed qgis desktop 2.6.0-brighton successfully. Here is my steps when installed the desktop : sudo apt-get install ...
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1answer
26 views

SAGA Cluster Analysis for grids projection issue

I am having an issue with the SAGA cluster analysis for grids tool within QGIS 2.4. I am actually taking this as an online class through Del Mar and we are going over supervised and unsupervised ...
3
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2answers
76 views

How can I determine which raster attribute covers the highest area of a polygon?

I'm relatively new to GIS and QGIS but I have a problem that I'm not certain how to solve. I searched here for relevant information but found none. (Or, I used incorrect search terms.) My problem ...
3
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0answers
18 views

QGIS Cross Section Profile Distance using Ellipsoid?

I am working with QGIS 1.8 and 2.6 and can't get any of the Cross Section Profile tools to provide the ellipsoid ("proper") distances. All the distances use geographic coordinates which are too ...
2
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1answer
41 views

How can I place a ETRS89 layer to WGS84 project in QGIS?

I've got a QGIS project with several layers with SRC EPSG·4326 - WGS84. I have downloaded from a government website a layer projected in ETRS89. I have tried my very best to match this new layer with ...
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3answers
59 views

how do I group layers in QGIS 2.4.0 [duplicate]

As written in the Title: How do I group layers in QGIS? I have tried dragging them on top of each other and looked in the layers setting but could not find anything.
2
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1answer
41 views

How to add documentation for QGIS Processing algorithms?

In the Processing modeler, many of the algorithm help tabs say: Sorry, no help is available for this algorithm. In the QGIS sourcecode, the processing algorithms seem to reside in: ...
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0answers
53 views

How to submit user scripts for Processing Toolbox (QGIS 2.6)?

QGIS 2.6 change-log says that now there is some kind of repository where users can submit their scripts to make them available for everyone. Unfortunately I was unable to find any details about how to ...
2
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2answers
83 views

Programatically use Openlayers plugin layer in Print Composer

I created some PyQGIS functions to set up a print composer, modify the layout (adding maps, legend, title...) and print the result as an image file. This works fine with one or several vector layers - ...
3
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1answer
49 views

GIS through Games: Ideas or Links [closed]

I'm managing a project - http://nepanode.anl.gov aimed at improving data awareness and sharing around Environmental impact analysis. I'm struggling to come up with ways to engage users and show them ...
3
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0answers
13 views

Action: Move pointfeature to other layer - Point becomes Multipoint

I'm trying to write an action that moves a pointfeature from one layer to another. It works fine until i try to save the layer with the new feature on. He says he can't save a MULTIPOINT to a ...
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1answer
35 views

how to split/cut a linestring with another a linestring

Is it possible to cut a linestring with another linestring where both of lines are coincidence using SQL to get a multilinestring?
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0answers
26 views

How to calculate 'off track' error from GPS data?

I'd like to analyse navigational accuracy, comparing planned transects with the actual track flown from GPS data. For example, the planned transects below (green) don't match perfectly with the actual ...
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1answer
24 views

importing shapefiles to postGIS on QGIS1.8

I am trying to import a shapefile into postgis from within QGIS 1.8. The QGIS is based on a server that is not managed by myself. I have requested an upgrade to QGIS 2.0 ...but this may take ...
3
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1answer
54 views

QGIS Plugin installed but reported as invalid

I'm just discovering QGIS so please excuse my ignorance! I have QGIS 2.4.0 installed, and am trying to install Ordnance Survey Mastermap data. I have installed the OS2OGR translator to handle the ...
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0answers
48 views

How to create shape file and show in map using Python?

I have calculated distance between longitude and latitude by import .csv using python. Now I want to show this points or distance between points in map. So how can i do it by using only python? and ...
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1answer
79 views

Installing QGIS for Viewing purpose only and not edit?

I would like to find out if it is possible to install QGIS to be able to view and query data but not be able to make edits,is this possible.Can someone please advice how to do this.
2
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1answer
35 views

How to export subset of data in QGIS to DXF

I have QGIS loaded with multiple layers. I want to save to .dxf but the map is so massive it results in a very large file. I only need a small portion of the map, so I was wondering how I can crop the ...
3
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1answer
50 views

QGIS Quantile method

I have a question about the quantile classification in QGIS (2.6 and master, windows or linux). I used the points in polygon fonction. I have 100 polygons. In the attributes of my 100 polygon I get ...
2
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1answer
54 views

Zebra grid style does not works in map composer

in Qgis 2.6, in Map composer, while selecting grid frame style as Zebra, it does not works. Also while drawing coordinates points as exterior in map convas, it is not displayed. Actually I am facing ...
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2answers
44 views

Exporting from Draftsight: how to set correct co-ordinate system

I'm trying to import a DXF into GIS (I have QGIS, Arcmap 9.2, GVsig ) The file has been given a coordinate system & appears to be the right size, just in the wrong place. In Draftsight (or any ...
3
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2answers
53 views

PyQGIS: Speed up for adding features and attribute arrays?

Context: I'm writing a dynamic import tool for QGIS (2.2 to 2.5) with python. Datatype: Binary Datasets with environmental simulations from HPC which might contain millions of features and terabytes ...
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2answers
44 views

how to know distance of a point to a shape in a certain orientated direction?

I have a point (in the middle of the sea) and I have to measure the distance from this point to the land. No big deal, I can use the measure tool. But what if I have to know exactly the distance ...
3
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1answer
56 views

Gaps and overlaps appear after cutting a previously topologically clean shapefile?

I'm using QGIS 2.2 and I have a polygon shapefile which was created by someone else. I have managed to get the shapefile to a topologically clean state by running v.clean but when I tried to cut the ...
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1answer
77 views

How can we merge the two selected features in a vector layer

I have taken one feature and find which are the neighbouring features to the feature which i have taken and then i have combine all those neighbouring features with my feature to make one feature. i ...
3
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1answer
36 views

Label points at regular interval using qgis

I have a point shapefile with a point index. Like the first picture. I'm trying to label the point index every 30 points to obtain the second screen capture. I also have an attribute R3 or R4 to ...
2
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0answers
47 views

How to add column to attribute table using field calculator with $length function?

I used the following code to add a separate column to the attribute table with the length of features. from PyQt4.QtCore import QVariant from qgis.core import QgsField, QgsExpression, QgsFeature ...
2
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1answer
36 views

Open Source counterpart to Euclidean Allocation

I'm looking for a function that can perform something similiar to the Euclidean Allocation process in arcGIS ...
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1answer
109 views

QGIS 2.6 Curriculum Redo?

We are in the middle of creating GIS curriculum based on QGIS. When we started in June 2014 it was still 2.2, then 2.4, now 2.6. You think it's worth returning to step 1 and begin again in 2.6?
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1answer
95 views

How to load a WMS layer using PyQGIS?

Although there are some posts on this matter, there is no answer in anyone of them. This is why I am asking it again. One post I found was Raster layer invalid I read information from the following ...
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0answers
26 views

Print composer in QGIS 2.4: Grid interval settings crash before changing values

I am using QGIS 2.4 in Mac OS 10.10 Yosemite. Just trying to produce a map with cartographic symbology in the print composer. Map data: polygon and line shapefiles projected in SAD69 / UTM zone 23S/ ...
2
votes
1answer
43 views

QGIS 25D shapefiles

I do know QGIS doesnt so far make use of 25/3D files, but If I do make use of 3D points from a say GPX file and thereafter, using snap, generate a new polygone shapefile. Will the z-coords be kept ...
4
votes
3answers
834 views

Should you switch from ArcMap to QGIS? [on hold]

Background: Our group has full ESRI licenses and applications built with ArcDesktop. We are invested in the arc geodatabase itself and will not change that tier. There is a proposal to switch from ...
1
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1answer
41 views

Use QGIS Gui's predefined colorramps in Python console / PyQGIS

When using the QGIS Gui, there are plenty of predefined colorramps to choose from when styling a layer with e.g. categorized symbology. When using the Python console for PyQGIS scripting, this page ...
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0answers
37 views

Loading virtual vector layer in QGIS

Can QGIS read layers in OGR's virtual vector format? It seems to work with VRT raster files, but it reports my layer is an invalid data source for vectors. http://www.gdal.org/drv_vrt.html I'm ...
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0answers
76 views

With Ubuntu 14.04 I get errors related to QGIS when I type sudo apt-get dist upgrade

Please advise me whether my question is a duplicate or not. This happened recently with QGIS 2.4 and Ubuntu 14.04. When I type sudo apt-get dist upgrade I get these messages - Any suggestions will be ...
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0answers
43 views

Can Virtual Fields be used for a rendering style?

In QGIS 2.6, creating a virtual field for a layer and adding up 2 integer fields work fine. I get the correct results and I can use that field for styling. However, when doing a Joins with 2 layers ...
2
votes
1answer
32 views

Why does the data type change from int to float when exporting layers? [closed]

When I export Shapefile layers to Mapinfo format or Shapefile format integer values are automatically converted into float. Is there anything I can do to avoid this?
2
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2answers
51 views

Find coordinates of given raster value

I would like to get the coordinates of a raster cell with a given value. I suppose many cells can take the same value, in which case several coordinates should be returned. In my first problem I'm ...
2
votes
2answers
59 views

How to show different attributes in print composer

we have shape file with different attributes wich we want to show in the print composer. The goal is that we open 1 vector layer and the print composer shows 4 different maps (4 attributes). Is there ...
2
votes
1answer
39 views

QGIS Technical problem in 'Extract nodes' command

I am trying to create a layer of nodes from an existing layer of line. For this I am using Vector> Geometry Tools > Extract nodes I, first, select the 'Input polygon vector layer' and then select ...
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1answer
35 views

“Node tool: could not snap to a segment on the current layer” message

I have a strange issue. Editing a layer with node tool I get always the following message: "Node tool: could not snap to a segment on the current layer." This error happens to me even with a fresh ...
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0answers
27 views

QGIS Atlas web layer rendering - how can I slow it down?

I cannot get Atlas to export maps with web layers correctly. When I look at the preview within composer everything works fine. When I export an atlas the first page renders ok but for subsequent ...
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1answer
78 views

how to send question to QGIS mailing list [closed]

I am not sure but everytime I post any question to QGIS mailing list, I get the below message? Am i doing something wrong? You are not allowed to post to this mailing list, and your message has been ...
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0answers
31 views

QGIS 2.4 Print Composer Will Not Export Image

I am running QGIS 2.4 on a Macbook Pro (Mavericks) and am having problems with the print composer. Recently, my composer window goes totally white when trying to export images or pdfs and nothing ...
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1answer
23 views

Selecting PostGIS objects out of given distance

I need to select by SQL querry objects that are further than 100m from specific type of road. For selecting object that are in given distance there is ST_DWithin but what to do in this case?