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

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270 views

How to extract NDVI values into polygon vector map with QGIS

I have calculated the NDVI values of a satellite image using the raster calculator. Now I need to have these NDVI values extracted into the attribute table of my polygon vector file. Is there a ...
0
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0answers
30 views

How can I remove dipoles from rasterlayer in QGIS 2.2?

I work with geomagnetic survey data. When convertet into a rasterlayer, every object with a high magnetic potential (for exampel an iron-nail on the surface) is shown as very sharp anomalie called ...
0
votes
1answer
103 views

Layer relations via Python

Is it possible to, through Python, to create the relations that it's possible to create in Layers/Properties/Fields/Relations, and if so how? I first thought these were saved in the styles, but that ...
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2answers
146 views

How to save QGIS composer template with image - e.g. company logo?

I can't figure out how to save QGIS Print composer template with image. In our map compositions we always have company logo in one place. It is easy to add image (logo) to composer and place it to ...
1
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2answers
107 views

How to disable “Simplify geometry” via Python?

After I've loaded a layer from a table in my db I'd like to disable the 'Simplify geometry' (found in Layers/Properties/Rendering) programatically using Python. I've tried several versions of ...
2
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2answers
629 views

How to import a 3D DXF file into QGIS with z information as attribute value?

I have a dxf file of 3d contours. after import it does have only layer,x,y attribute and doesn't have Z attribute. how can I provide Z attribute to create a TIN file.
2
votes
3answers
1k views

QGIS 2.2 Crash dumped on Windows 8.1

After I installed QGIS 2.2 via OSGeo4W, as I click the icon of QGIS, then it shows this up, so I can't open QGIS 2.2 Here's some look like troublesome lines in my installation log, 2014/03/23 ...
4
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0answers
435 views

How to create multi-ring buffers automatically in QGIS? [duplicate]

I'm wondering if anyone knows of a tool or plugin for QGIS that allows for multi-ring buffers. I've found a post about doing multiple buffers one by one, but was hoping there was a way to do this all ...
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0answers
68 views

QGIS 1.8 runtime error under Windows 8.1

I tried to open qgis 1.8, and everytime I click its icon on my desktop, shows this, and then it crashed, thus I always couldn't open it. I saw an analogous question in this post, Microsoft visual ...
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1answer
245 views

Why is shapefile layer not visible on WMS layer in QGIS?

In my QGIS project I have added a WMS layer for which the CRS is WGS84 EPSG:4326. Now I want to show my shapefile layer which has the same CRS. QGIS shows the layer separately but does not show with ...
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0answers
313 views

Editing QGIS point layer: retrieve attributes of intersecting line layer

I'm creating a custom editing form using QGIS 2.0 and would like to modify the mouse event when creating a point. I've gotten a start by reading this thread: How to programatically check for a mouse ...
2
votes
2answers
763 views

How to set Eclipse and PyDev for QGIS when ArcGIS is installed?

I have got a lot problems with the configuration of Eclipse with PyDev in order to develop QGIS plugins. The situation is very weird and frustrating. I can import qgis module using Pyscripter without ...
3
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2answers
225 views

How to remove/disable a toolbar via python?

How do I remove or disable a toolbar e.g., Raster, programmatically using Python?
2
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0answers
80 views

Zonal Statistics Freezing QGIS 2.2

Running on Windows; 8gb memory, 500gb HD, i5 cpu; Raster file: 250mb I am having a problem with zonal statistics advancing past 17%. I am trying to run statistics on a crop grown in certain counties. ...
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0answers
150 views

I had an error in Gdalwarp and i don't know the reason

I was trying to warp a raster using a mask and shift it before clipping but when i exectute the command bellow in Qgis/PyQt using QProcess: gdalwarp -s_srs "+proj=merc +a=6378137 +b=6356752 ...
1
vote
1answer
273 views

How do I add a corel scale drawing

I have a plan of a building, drawn to scale in Corel Draw. The whole drawing was 'surveyed' using the principal of taking distances from of each of these 2 points to identify the location of a 3rd ...
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3answers
2k views

QGIS 2.0.1.3 (Dufour) and 2..2.0.1 (Valmiera) 64 Bit versions: uninstall not completely possible, crashes at exit

haven't tried the stackexchange page before, but since I can't find information on this problem: I can't completely uninstall QGIS, I want to do a complete, clean reinstall, but whenever I start the ...
2
votes
1answer
174 views

Update postgres/postgis point data attribute from another enclosed polygon shapefile in QGIS

I have a placename point table in postgis with 'district' column. a districts polygon shapefile with district name in 'Name' column. See the image below. I would like to update the 'district' ...
2
votes
1answer
613 views

Importing otb into Python

I have Python 2.7 (installed together with ArcGIS 10.1). Via OSGeo4W a have installed qGIS and otb application.I was able to connect qGIS and otb and it's working fine. Through OSGeo installer I ...
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2answers
398 views

How to create a symbol with no fill color in qgis?

Where can I find a simple circle to draw it around a point feature. I can change symbol fill color as well as symbol border color. But I didn't find a way to set fill color to no color.
3
votes
1answer
420 views

How to create a x-y scatterplot from attributes in QGIS 2.0?

There are a few old packages that allow the creation of x-y scatter plots from attributes in vector data (Scattergram for 1.7) http://plugins.qgis.org/plugins/scattergrammidentify/ (SPQR for very ...
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3answers
1k views

Can't compile python plugin in QGIS (Windows)

I'm just installed QGIS 2.2 and created a new plugin from Plugin Builder. When I try to compile the plugin using: C:\Program Files\QGIS Valmiera\bin>pyuic4 -o C:\Program Files\QGIS Valmiera\bin\ ...
0
votes
1answer
204 views

How to prevent QGis (MMQGIS plugin) from interpreting numbers as strings [duplicate]

I'm using the MMQGis plugin to "Join Attributes From CSV" into a shape file and am having trouble getting QGis to interpret some numbers as numbers (rather than strings which is what its doing). This ...
2
votes
2answers
142 views

Is it possible to run a spatial query in QGIS 2.0 across multiple layers using a user-specified radius from a point?

I would like to be able to click on a point on a map to select all vector features (from multiple layers) within a specified radius of the point. Can anyone point me in the direction of how to do this ...
3
votes
3answers
890 views

Convert 800 .hdf4 files to Tiff using GRASS/QGIS/SAGA/GDAL/R

I've have MODIS ndvi data (MODIS_Grid_16 days NDVI) from the iberian peninsula, from February of 2000 to August of 2012 (really big data). How do I batch convert about 800 .hdf MODIS files to .tif ? ...
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0answers
51 views

Delayed moving average

I want to develop a plot of delayed moving average. The code for this in MATLAB is: nr_pontos = 36; coefs_filtro = ones(1, nr_pontos)/nr_pontos; data_dma = filter(coefs_filtro, 1, data); ...
0
votes
1answer
25 views

Given two Shapefiles, how to tell which one's CRS is set correctly?

I have a polygon shapefile projected in greekgrid (GGRS87_Greek_Grid) then I open an other shapefile which is in ETRS_1989_LAEA In ARCGIS 9.3 the two shapefiles are displayed correctly. But if I do ...
1
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1answer
78 views

Why are some layers saved with custom CRS while others use the appropriate EPSG code?

I have a number of .shp's that I have converted from EPSG 4148 to CPNO27. Some have come out perfectly and others revert to EPSG 1000007. I have checked and the only difference between the two is the ...
1
vote
2answers
156 views

How to avoid snapping errors in QGis?

I am using QGis version 2.2.0 and I set the snapping option to the vertex, with a tolerance of 1.5 meter. When I draw a new polygon next to an old one, it seems like the vertices are automatically ...
1
vote
1answer
240 views

What do “count”, “mean”, and “sum” in QgsZonalStatistics mean?

I am working with Qgis and making some analytics of lightdata. I've used these commands: rasterfile = qgis.utils.iface.mapCanvas().currentLayer().source() vectorlayer = ...
2
votes
1answer
96 views

how do i get a GDAL(using gdalwarp) clipped layer projected in pseudo mercator ESPG:3857 to not be shifted?

how do i get a GDAL rasterized layer projected in pseudo mercator ESPG:3857 to not be shifted ? i have a vector layer projected in ESPG:3857,after rasterizing using this command: gdal_rasterize ...
1
vote
1answer
177 views

Running model in QGIS gives ERROR: Missing mandatory parameter?

I am trying to make a batch model to convert band 2 and band 1 MODIS 8 day composites into NDVI. The input files are in tif format, but I want the output to be saved in Idrisi .rst format. I am ...
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0answers
200 views

Workflow with raster in Qgis 2.2

I'm trying to build a workflow with the Qgis 2.2 processing toolbox. I want to clip a raster layer with a vector layer using the GDAL tool "clip with a layer mask". But it doesn't work. The error ...
1
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3answers
83 views

How can I change more than one attibute at the same time?

I'm working in QGIS 2.0.1 Dufour. I started by cretaing a shape file form an AutoCad file. The problem is that in the AutoCad, my layers had symbols like: "~; ç; ^". As the QGIS does not support this ...
0
votes
1answer
213 views

Coordinate mix up

I am working on a basic map, pulling coordinates from google earth, converting them to decimal degrees in excel, and then importing them into qgis. I am using qgis 1.8. When converting from degrees, ...
0
votes
1answer
136 views

Qgis Spatial Join: problem with a column!

I run the function "Join attributes by location" in Qgis 2.2 between a point vector layer and a polygon vector layer. When I open the resulting table of contents of point layer there is a column of ...
0
votes
1answer
37 views

How to do a search in a line to a specific point

I'm using QGIS 2.0.1 Dufour. I'm working with a shape file made by a single line that represents a road with 30km. In that line I want to attach pdf files containing information about some points in ...
2
votes
1answer
91 views

Length of a line within a surface

I need to find out the lengt of each line within a surface. I have approx. 20'000 diferent lines and around 10'000 different surfaces. what kind of SQL-sentences do I need to use? I've tried things ...
1
vote
2answers
121 views

Suggest an algorithm to measure how a node is connected to road network

I try to measure how well a node is connected to the rest of the network. If a city has a distant suburb connected with one sole road, it's connectedness is, say 1. If it's connected by 2 roads, it's ...
1
vote
1answer
278 views

problem reading netcdf

I am using qgis 2.2 (I have also tried this in qgis 2.0 and arcgis 10 with the same result) (I have some basic understanding of netcdf, but I am probably missing a lot of details...) I have manged to ...
0
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0answers
223 views

Mac QGIS 2.2 error executing Python code

Newbie Using QGIS version 2.2 with Python 2.7.5 on OSx 10.9.2 Getting the following error. Any idea on how to resolve? I'm not sure if it has ramifications on the display of the Google data. An ...
2
votes
1answer
1k views

import qgis.core problem with QgsFeature and QgsGeometry

I've tried several previous answers to similar questions - no luck. I run Win7. I installed QGIS 2.2.0 using the OSGeo4W 32-bit installer. Problem 1) from qgis.core import * failed. Solution 1) ...
0
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0answers
67 views

Why does it take so long to run zonal statistics?

QGIS 2.0 Windows 7 I have pulled agricultural data from NASS CDL in tiff format. I want to track where a certain crop has grown over the years. My intention was to use a county shapefile overlaid ...
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2answers
105 views

How to use eVis to launch AutoCAD with a relative path?

I found this post, which leads me towards what I need: How to link to external files with relative path in QGIS actions? Now, I'm trying to use the eVis plugin to open .DWG and .DXF by launching ...
2
votes
1answer
186 views

Add objects from one layer to another at QGIS

How can I add some objects from one layer to another one. I mean, I have one layer with specific data(e.gg polyline) at the same time I have another layer with different objects .how can I copy/move ...
0
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1answer
89 views

work with emf files at QGIS?

how to convert EMF files to shapefile at QGIS? Actually I have EMF file that has been generated from Autocad-Civil3d. Thanks Hamid
2
votes
1answer
640 views

How can I copy columns from layer 1 to layer 2?

I have two layers, the first layer is pipe: that has some fields (column) title like : length, id, material. Also I have another layer that is empty (without any fields). How can I copy fields ...
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1answer
475 views

project points to a vector layer and get z elevation at QGIS

one point file and one dtm vector file. how can I project points to the vector file and get z elevation of them. Thanks Hamid
11
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2answers
3k views

Is there a good qml or sld file available for QGIS + Openstreetmap data?

I'm looking for a qml file (or equivalent e.g. sld) to allow me to use QGIS to take Openstreetmap data and produce paper maps. I'm re-asking this question (it was asked once or twice over a couple of ...
1
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1answer
130 views

Are unicode symbols supported in QGIS labels?

I want to use unicode symbols in a QGIS label - is this supported? I.e. I have this expression for labelling a line: case when xat(-1) - xat(0) > 0 then 'GF ->' else '<- GF' end and ...