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

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2
votes
1answer
132 views

Save a table in ascending order in QGIS [duplicate]

Is there a quick way to sort an attribute table in QGIS in ascending order permanently and save it? My third column is an integrer, of course if I clik on the header the table will be sorted in ...
1
vote
0answers
17 views

Creating Shape by Density Criteria using QGIS?

I have a map with points plotted. Is there a way that I can make a circle of a certain radius (let's assume 10 miles) if the density of points in any given 10 mile radius is over a certain number?
1
vote
0answers
90 views

Why does the “local maxima” module in SAGA GIS put so many “maxima” points on lakes and plains?

SAGA GIS puts too many maxima points on plains and lakes. Why does it happen? Is there a way to avoid this? It's not really a big problem (the value is correct) except for the size of the SHP files in ...
0
votes
0answers
110 views

How to create a Shapefile of a subset of input features in PyQGIS?

I'm having some trouble applying my Python skills to develop some scripts in PyQGIS. For me it's far simpler to write it in ArcPy, but then again I wouldn't get that much satisfaction after finishing ...
1
vote
1answer
40 views

Is it possible to display irregular values in the scale bar in QGIS 2.8?

Is it possible to display irregular - increasing values in scale bar in print composer? For example: 5, 20, 100, 250.
1
vote
0answers
72 views

Merge vector layers problem with german names (ä, ü, ö…)

When I'm trying to merge (saga merge layers tool) some shape files I get an error log 'ascii' codec can't decode byte 0xfc in position 91: ordinal not in range(128) See log for more details ...
0
votes
1answer
129 views

How to eliminate polygon overlap areas in QGIS?

Is there a way to remove polygon overlaps within the same layer using QGIS, preferably removing the overlap area of the biggest polygon (having the greatest surface)? All of my polygons are in the ...
1
vote
1answer
250 views

QGIS Python Scripting permission denied

I've just started a Python Scripting tutorial on QGIS. The problem arrives right at the end, when I have to use this script: output_file = open('c:/Users/Ujaval/Desktop/airports.txt', 'w') for f in ...
1
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0answers
105 views

Masking Labeles in the Compositor in QGIS 2.8.1

I am looking for a way to remove/mask out Labels that are under a composer Element (Overview Map), which I moved in front of my main map. Is there no way to do this? Maybe using the ItemID? I tried ...
1
vote
1answer
187 views

Function to merge geojson and csv data in R

I have been using merge() to merge my geojson file with csv data in R. My codes are as follows: map@data <- merge(map@data, csvdata, by.x="ID", by.y="ID") However, after exporting the geojson ...
1
vote
3answers
144 views

Create a reference number (id) based on x coordinate in QGIS

I would like to add a reference number to a point table. I would like this value to increase as I move from west to east across my data. So the values read 1 to n from west to east. I have an ...
1
vote
1answer
283 views

Receiving NULL values from Point Sampling Tool in QGIS

I am using QGIS 2.8.2. My project includes a raster layer of flow depth representing the output from a flood simulation (.DAT file). It also includes a vector layer of points representing the ...
1
vote
1answer
339 views

where to download gdal_polygonize.py?

I am trying to help out a friend of mine. She learnt GIS in school in the past using ArcGIS but has recently installed QGIS package on her Mac OSX. When she tries to render raster into shape file, ...
0
votes
1answer
40 views

Spatialite table column is function in itself

GOAL: I'm trying to filter all the 1's in a spatial boolean operation in Qspatialite, the spatialite plugin for QGIS. ATTEMPTED SOLUTION: My solution is to perform the boolean query first, export the ...
1
vote
1answer
444 views

Excel XLSX data with coordinates displayed as points

I am preparing a course for QGIS newbies, which includes handling Excel spreadsheet data in QGIS. It's so easy: Just drag an XLS, XSLX or CSV from Windows Explorer to QGIS! For data with no ...
0
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0answers
41 views

Grass functions (for example, r.li) on QGIS Processing Toolbox

I need to know if it is possible to add other functions, such as r.li to Processing Toolbox. Thanks.
2
votes
2answers
123 views

Is it possible to georeference raster stored in Postgis?

I'm looking to store a huge raster aerial image (400 Gb) into Postgis, but before storing it i like to know how i could georeference or rectify raster stored in postgis ? is there any Qgis plugins ...
1
vote
2answers
37 views

How to coincide two geometries which has difference in positioning?

I have two vector layers one representing countries and other representing states. I have states which is slightly dis positioned so that it is not exactly not coinciding with the country.Algorithm ...
2
votes
1answer
113 views

QGIS freezing/stalling?

I've been using QGIS for more than a year now (currently using 2.8.2 on MacOS 10.10.3, but also in Windows XP via VirtualBox for troubleshooting) and the application has been freezing and stalling ...
0
votes
1answer
105 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 ...
0
votes
0answers
374 views

Processing LAS dataset in QGIS 2.8.2 [duplicate]

I need to extract DEM from LIDAR dataset in QGIS 2.8.2. I have installed LAS tools in QGIS. I cannot configure my LAStools because I do not get Processing-->Options and Configuration and instead I get ...
0
votes
5answers
406 views

How to create 10m DEM from 30m DEM?

I am not regularly working in raster analysis. I have a 30M DEM and I would like to create a 10 DEM out of that. Is it possible to do this using QGIS? and How? EDIT: (I understand that a sub ...
0
votes
1answer
150 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
votes
1answer
64 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 ...
2
votes
2answers
327 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 ...
2
votes
3answers
128 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.
1
vote
2answers
610 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 4....
1
vote
0answers
35 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 ...
4
votes
4answers
1k 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
votes
1answer
194 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 ...
2
votes
2answers
213 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 tools/...
0
votes
1answer
64 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
votes
1answer
414 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: '...
18
votes
0answers
198 views

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

I've been trying to use the heatmap plugin on QGIS (2.8.2) on Ubuntu(14.04) but the drop down for the output formats doesn't get populated. Selecting the drop-down allows me to press OK on the ...
3
votes
1answer
185 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 ...
1
vote
0answers
219 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 ...
1
vote
1answer
294 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
vote
1answer
266 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
votes
0answers
52 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 ...
3
votes
1answer
89 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 ...
2
votes
2answers
88 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 ...
0
votes
0answers
215 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 ...
2
votes
1answer
98 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 !
3
votes
3answers
430 views

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 ...
1
vote
1answer
1k 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 ...
0
votes
0answers
44 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
172 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
165 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 ...
3
votes
2answers
165 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 AlphaList=["A","B","C","...
1
vote
1answer
361 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 ...