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

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1answer
44 views

Cannot edit polygons in Qgis

I have a google Layer map on top of which I have added a raster layer of Image and then mapped image coordinates from Google layer. I made transparent (75%) image map layer and now mapping and ...
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0answers
29 views

Problem filling raster “gaps” (No-Data cells) by means of different raster

Let's assume I have two (or more) rasters with different resolutions which describe the same area. I would like to combine them - fill "gaps" - use value from the second raster when value in the first ...
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5answers
111 views

How can I create a 10m DEM from the 30M DEM with me?

I am not regularly working in raster analysis. I have got a 30M DEM with me and I would like to create a 10 DEM out of that. Is it possible to do this using QGIS? and How? EDIT: I have got the ...
0
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1answer
33 views

Geographic crime profiling in QGIS?

How would you implement geographic profiling in QGIS? There doesn't seem to be any pre-existing plugins and my Python skills are not quite good enough to implement it myself. Specifically, Rossmo's ...
2
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1answer
22 views

How can I convert climatic text data to raster in QGIS and ArcGIS?

I have been provided with text (*txt) formatted, tabular climatic data. How can I convert climatic text data to raster in QGIS and ArcGIS? In addition to tabular data, the following information is ...
1
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1answer
40 views

QGIS: why does clipping a raster alters cell size?

Using QGIS V 2.2.0 (OS-Windows 8), I need to prepare raster files (ESRI ArcInfo Grids) to be later used in a species distribucion model using MaxEnt. Each of the original raster files (environmental ...
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3answers
52 views

Is there any way to freeze the layer names in the TOC?

I would like to freeze the names of layers in TOC. Is there any way to do this via QGIS config or PyQGIS? I´m using QGIS Wien.
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0answers
13 views

How to show a QGis map in Qt/C++ custom widget with QgsMapCanvas?

I'm trying to add a QGis map in Qt/C++ widget using QgsMapCanvas, but I have some problems... I'm working with the following environment: - Ubuntu 12.04 - QGis 2.8.1 - Qt Creator 2.4.1 (based on Qt ...
1
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0answers
23 views

Attribute error with FileGDB

I have a large ESRI file geodatabase, that I loaded into QGIS with no problems. If I look at the attributes tab in the properties dialog, the fields are as they should be. One of the fields is ...
3
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4answers
94 views

Checking if polygon fits inside another polygon using ArcGIS or QGIS?

How do I check if one polygon fits inside another polygon? Furthermore how do I automatically check if one polygon fits in other polygons of my shapefile? I have a shapefile with thousands of ...
0
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1answer
44 views

Is it possible to show 3d models using QGIS?

I can show vector layers from PostGIS using QGsMapCanvas and QGsVectorLayer in my standalone application. But now I need to show 3d models, for example 3dmax or sketchup, of some buildings over vector ...
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2answers
37 views

Automating selection and sliver elimination using QGIS

At the moment I do this manually: open a shape file open the attribute table use "select features using an expression" - the expression is "area" < 200 then I use vector/geoprocessing ...
0
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1answer
41 views

How to compile QGIS master snapshot from a certain point in history?

I would like to find out which commit in QGIS code caused a certain change in behaviour. Since the archives at http://download2.osgeo.org/osgeo4w/release/qgis/qgis-dev/ are not complete, I think that ...
0
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1answer
37 views

Install OTB (Orfeo Toolbox) for Qgis Wien (2.8) on Ubuntu 15.04

I want to install OTB in Ubuntu 15.04. The unstable Ubuntugis is installed, but OTB itself is not available as package. I tried sudo apt-get install otb-bin otb-bin-qt python-otb and get: ...
1
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0answers
10 views

Output formats for QGIS Heatmap plugin not appearing in drop-drown in Ubuntu

I've been trying to use the heatmap plugin on QGIS (2.8.2) on Ubuntu but the drop down for the output formats doesn't get populated. Selecting the drop-down allows me to press OK on the plugin popup ...
0
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0answers
10 views

Error in executing the command to integrate the antennas

Can somebody tell me why the program shows me this error: "ERROR:Error(s) while processing 'model' commands, exiting" when I execute the command to integrate 3 antennas into the map. I have integrated ...
2
votes
1answer
33 views

Qgis docking plugin - python

I need to create a dock plugin for QGIS using QT designer and Python. I've created a basic plugin in "plugin builder". Then I've changed the .ui so now I dont have standard QDialog box but a ...
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0answers
15 views

QGIS version 2.7 Roadgraph Plugin

Where can I find and download the Roadgraph Plugin for QGIS 2.7?
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0answers
55 views

Connect to PostGIS database from Q GIS

I am having trouble connecting to a postgresql database hosed on my local host. I have gotten a python script to connect and connected through the command line, but for the life of me cant connect to ...
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0answers
5 views

Unlock a file after using GRASS runalg

I am not allowed to supress a shp file after using: processing.runalg("grass:v.surf.idw","the_file_i_want_to_delete.shp",12,2,"Arithmetic",False,"-125,-65,23,50",0.2,-1,0.001,"output") Any idea? I ...
0
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0answers
27 views

View of relationship in pgAdmin III using QGIS? [closed]

I created the entity–relationship model in pgAdmin III. I imported the database in QGIS. Is there some way in QGIS to view the relationship between the entities? Or I do I need to create all of ...
1
vote
1answer
56 views

Installing tweepy for tweeter 2qgis?

I installed the plugin "tweeter 2qgis", I need the Python library "tweepy". Downloading the plugin, a dialog window appeared, saying "we will download tweepy to your temp folder, but you must ...
1
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1answer
22 views

Creating labels with Umlauts, accents, etc. in QGIS

I have a problem labeling features with special characters like French accents, umlauts, etc. I have the names in the attribute table, but names like Niafunké are displayed Niafunk�. I assume it has ...
2
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0answers
23 views

Linking URLs through actions in .url format for QGIS?

I need to link some DWG files. Normally I'd do that with a simple cmd /c start ""[% "Link_DWG" %]"" where "Link_DWG" is an attribute containing the URL of the file. My problem is that I need to ...
1
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1answer
28 views

fTool in pyqgis: Is it possible?

I am doing a work which I need to sample random points for many layers (classification of land use). Then, I'm trying to do a loop with my several layers and applied a functions of random pointos. I ...
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0answers
31 views

Extending line by adding point at end of it using QGIS?

I'm using QGIS 2.8 to modify a line. I need to add a point on one end of this line, and then move this new point further away, leaving the original end point in the same place. I can manage to create ...
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0answers
21 views

Create table that assigns node id of linked node to line endpoints in QGIS 2.8?

I am using Quantum GIS 2.8.1. I have two vector files - 1 line, 1 node (vertex). All lines are connected to a node on either end. I want to create a table of every line with a start node and end node ...
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0answers
19 views

what is the appropriate method to perform spatial and non spatial analysis of survey data travel behavior? [closed]

I'm doing research on the travel behavior of students to the campus. Questionnaire survey data I have collected about socioeconomic characteristics, namely the location of residence, duration of ...
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0answers
42 views

QGIS interpolation gives same value across the grid, what am I doing wrong?

Following this question, I've tried to use interpolation in QGIS to get a sense of the topography of a map based on about 3500 track points with elevation. The elevation ranges between 213 and 353 ...
1
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1answer
61 views

Logging layers openings?

i would like to log every layers openings in PyQGIS, regardless of the opened project. Is there a way to achieve that ? Where should be the Python code be located in that case ? Thanks for your help ! ...
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0answers
33 views
+50

How to make a local copy of a large WFS dataset?

We are writing a application in which a part of the job is to fetch a relatively large (>10000 features) and often updated dataset from a WFS server, store a local copy, and do geospatial analyses on ...
2
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1answer
42 views

How to compute distances between points and polygon borders?

I have point data and polygon in vector format. For each point, I want the distance from the point to the border of the polygon. However, if the point is inside the polygon, I want negative distance ...
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0answers
31 views

Georeference a computed tomography image without changing its proportions in QGIS

I have several images obtained from a Micro computed tomography (mCT). The scanned elements are human teeth. In a particular mCT slice, I have introduced a cartesian plot with its X and Y axis. The ...
2
votes
1answer
41 views

How to get mean geographic direction of a polygon in QGIS?

I have a raster height model and would like to calculate the horizontal geographic direction (north, east, etc. - orientation) of each cell, then calculate then the mean value of all these cells in ...
3
votes
4answers
74 views

Calculate minimum area where x% of raster value total is concentrated within polygons

I have a raster layer (chlorophyll concentration) and a layer of non-overlapping polygons (regions of the ocean). For each polygon, I'd like to calculate the area where the majority of chlorophyll is ...
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2answers
34 views

Raster Caculator Qgis 2.6 v/s Gdal_calc.py by Terminal

I need calculated monthly mean of Snowcover data by MODIS product, and then modify this script gdal_calc.py in this section # create alphabetic list for storing input layers ...
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0answers
14 views

gHydraulic plugin for QGIS 2.8 make EPANET Model Type Error

I've set up my water network layers to create an EPANET model using the gHydraulics plugin for QGIS 2.8: pipes, junctions, and a reservoir. The pipes have unique IDs, with their corresponding ...
1
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0answers
21 views

QGIS Processing Modeler: Join attributes by location

If I use "Join attributes by location" from the menu it works fine but if I'm using it within the Processing modeler it's not working. I want to sum up previously selected records having a field area ...
0
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2answers
64 views

Create a script to add delimited text layer in QGIS

I'm trying to use QgsVectorLayer() function to add delimited text layer in QGIS. So I have a txt file (T_1999_1_2.txt) in path: "D:\PATRICIA\DOCUMENTOS\ESTACOES METEOROLOGICAS\DADOS METEOROLOGICOS\T" ...
-1
votes
1answer
13 views

QgsComposerMap does not fit extent

Please help me to fit the map extent into de qgscomposermap size. printable_layers = QgsMapLayerRegistry.instance().mapLayers().values() printable_layers_ids = [] ...
-2
votes
0answers
15 views

R6034 - Runtime error while installing QGIS 2.8.2 [duplicate]

Please help me install version 2.8.2. I have the previous 2 versions also installed in my system and am working on it.
0
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1answer
27 views

QGIS how to delete virtual fields?

I can't find the option to delete a virtual field on a layer, not even in the table manager plugin. Where is that option?
2
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1answer
38 views

Qt/C++ Hello World application with QGIS not compiled: qgsconfig.h not found

I am a Qt/C++ developer. I have to create a GUI application (Qt/C++) with GIS maps. I'm trying to do that using QGIS. I'm working in Linux Ubuntu with Qt Creator 2.4.1 (based on Qt 4.8.0). I did the ...
1
vote
0answers
37 views

Creating a single layer of polygons from a point layer

I have a csv file of lats and lons for points that represent the vertices of parcels of land. I want to create a polygon for each set of specific points within the csv and then create one unified ...
0
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0answers
21 views

Merging data into borders using QGIS? [closed]

I have collected data into a spatial grid from an entire city what I have to do now is to cut this grid in a smaller borders, how can I do this?
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0answers
28 views

Can I style basemaps provided by OpenLayers in QGIS?

I absolutely love openlayers plugin, and it's been great help. It'd be greater if I can style the base maps such as disabling labels, changing opacity etc, which are all possible when working with ...
1
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0answers
18 views

Enable LWGEOM for OGR tools (QGIS 2.8)

I am doing some scripted operations on a Spatialite DB using OGRINFO, OGR2OGR etc. in the QGIS 2.8 OSGEO4W shell. Unfortunately, LWGEOM functions such as ST_Split() are unavailable and ...
0
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1answer
29 views

Converting multiple vector layers to georeferenced rasters using QGIS?

I have Openstreetmap background loaded in QGIS - currently from Spatialite, but no problem to get shapefiles. I need to convert the loaded map to one big raster or could also by more smaller ones, ...
0
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0answers
20 views

Mean values of data with the same coordinates within a single layer

I'm a new user of QGIS so this is probably and hopefully an easy problem to solve ;) I added a point layer by importing data from excel and want to get mean values of all data with the same ...
0
votes
1answer
30 views

QGIS / Python: Fill new field with values based on other fields and lookup table

I am trying to use Python for QGIS to add values to new fields in an attribute table based on existing fields and values in a lookup table. Attribute table I wish to modify (with example rows): farm ...