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

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Qgis becomes unresponsive when adding layers

Qgis suddenly won't allow addition of vector layers when running on PC (Lyon 2.12.1). I've reinstalled it, no help. I've recently changed to Windows 10 from 7, otherwise nothing much has changed on ...
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1answer
19 views

Style file with QGIS

So I created a very good symbol layout for a current map. I will be creating similar maps just different regions and want to keep the symbols and markers that way they are. The new data will have ...
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1answer
14 views

How to calculate area in sq m - troubleshooting projection issues in a global dataset in QGIS

I am using QGIS version 2.12.3. I have 3 polygon shapefiles: A, B and the intersect of A and B, which we can call C. All I want is to add a field to the attributes table of each shapefile giving ...
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14 views

snapping line nodes to points

I have a dataset of manholes and pipes; I want to snap the lines start and end nodes to the manholes if they are within a specified distance. Been trying to find away to do this using PostGIS or QGIS ...
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2answers
21 views

How can I handle NULL values in a color ramp? [duplicate]

I'm mapping areas in QGIS 2.12 based on average pricing, using area polygons (PostGIS) joined with a CSV data table that doesn't have values for areas that didn't have any sales. I'd like to color ...
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1answer
22 views

Locating and adding state layers to a QGIS map.

If I wanted to add layers for a state (Indiana) in a program like QGIS so I could produce several maps (Infrastructure, Water Resources, Mineral Resources, and HAZMAT concerns), how would I locate and ...
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11 views

Get the same coordinates for points after downloading a .osm file

I downloaded a .kml file that contains bike stations which I know the coordinates (latitude and longitude). So I got a layer that contains points corresponding to the stations. Then I downloaded the ...
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14 views

How to select within a distance using QGIS [duplicate]

With QGIS 2.12.3, I have two projected EPSG:2927 point shapefiles, A and B. I would like to create a selection of A points that are within 100 meters of any B point. This is easy in Arc, using the ...
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15 views

QGIS Atlas pages with different raster base layers?

Is it possible to enable raster layers only for specific Atlas pages, without using multiple map Windows? Unfortunately, there is no way to set transparency of raster layers by an expression ...
2
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1answer
20 views

Excel Tables as Labels or Annotations

I would like to take excel tables and place them in a label or annotation so that I no longer have to copy and paste them into the figure layout as picture objects. I know this isn't possible in ...
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1answer
12 views

Error when using viewshed analyis plugin with merged shapefile

I am using Qgis 2.12Lyon and try to run a viewshed analysis to show the intervisibility between several points in more than one shapefile. I have a digital elevation model (.tif) which is projected ...
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0answers
4 views

QGIS Server - I can't update QGIS layers that don't have a geometry field via WFS

I am using some layers that are data only (no geometry field). These tables are related to other geometric layers, as you can see in the config below : When trying to publish in WFS these "no ...
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1answer
18 views

How to turn a point layer into classified proportional circles in QGIS 2.12?

I'm trying to style a point layer representing cities around the Mediterranean following these two rules : The points should be represented as proportional circles, following a classification in 5 ...
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14 views

Looking for real examples of using GIS in logistics and transport systems (maritime, auto, rail) [on hold]

As mentioned in title I'm looking for real examples of using GIS in logistics and transport systems. To be specific I'm trying to find any articles or books with detailed explanation of achieved goal ...
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0answers
11 views

How to get a multi-attributes vector from an SRTM raster in QGIS?

I split an SRTM raster into 3 different raster files representing the altitude, the slope and the exposure, using QGIS DEM analysis tools. How can I output a single vector file with the 3 attributes ...
2
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1answer
36 views

How to create a fishnet/grid along a polyline or polygon

I am trying to generate a fishnet/grid along a line/polyline or polygon boundary in ArcGis 10.3 or QGIS. While it is totally intuitive and easy to generate a box-standard grid, what I am trying to do ...
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1answer
20 views

QGIS ignoring column when performing “Join Attributes by Location”

I'm using QGIS 2.12.3-Lyon. I have a polygon layer (grid-ish) and I have imported a road network from OpenStreetMap (via Geofabrik) for my study area. I used the field calculator to assign a numeric ...
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0answers
24 views

How to select a WMS layer style in QGIS

WMS standard allows specifying a list of styles for each WMS layer. The users can then use the style name in the URL query parameter "STYLES". If the styles are not specified, "default" is assumed. ...
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0answers
12 views

QGIS Modeler different results by calculate the $area [on hold]

When I use the graphic modeler,add a field and calculate the $area, the sum of all records different to values of the normal field calculator. What causes this discrepancy?
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1answer
13 views

QGIS Plugin 'make' error on Windows

Creating QGIS plugin via PluginBuilder and compiling resources via simple 'make' works straightforward under Linux (SuSe 13.2). Under Windows 'make' (3.81) produces an error: ...
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1answer
21 views

creating a transparent layer background in QGIS

I have created a heatmap in QGIS to cover my point data and I have saved it as geoTiff so that I can import into tilemill, which I managed to do but my background is black .In QGIS however I want ...
2
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1answer
17 views

QGIS - Installation issue Windows 7 64 bit

I am currently trying to install QGIS but it has been on the same point of the installation for almost 30 minutes. I don't know if it is simply taking a long time to create a folder, but it seems as ...
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0answers
16 views

Reclassification of CORINE map using R

I am trying to reclassify the CORINE map for Hungary to 4 classes in R. but after reclassification, when I import the asc file to QGIS it loads it empty. Am I doing something wrong? ...
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2answers
42 views

How to select the most populated neighbourhood of each town in the country using QGIS?

I have data from a national census with population for each neighbourhood, grouped by municipality and town, in the country. I want to select the most populated neighbourhood of each town (there's a ...
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0answers
18 views

Spatial Join Hangs on Two Specific Shapefiles in QGIS 2.8

I have successfully done spatial joins with QGIS many times. However, with two shapefiles QGIS hangs or never seems to complete. (I’ve let the process run for over two hours.) I’ve tried all the ...
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1answer
22 views

Creating DEM from topography map in QGIS [duplicate]

For my geology diploma project I need to create DEM from topography map my professor gave me to use as a base map. The map is georeferenced. My idea was to draw lines over the izolines of the map, ...
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25 views

ST_Intersection between MultiPolygon tables leads to gaps, missing intersections

I am trying to intersect two MultiPolygon tables, which are in the same UTM projection, and calculate the area of their intersections. I am getting some surprising results when I examine the ...
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0answers
14 views

QGIS Download getting stuck, NSIS error? [on hold]

I need to edit a DBF file, and I tried to install QGIS at http://www.qgis.org/en/site/forusers/download.html. However, none of the standalone installers work. I tried installing 32/64bit, ...
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1answer
23 views

Changing point data coordinate system without moving points in QGIS?

I made a mistake regarding coordinate systems and lining up two layers. I have a raster with elevations in EPSG:2949. I created a point data shapefile and entered about 600 hundred points manually ...
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0answers
36 views

Create a layer, edit and save. Where are my features?

I created a layer (e.g. point) in QGIS with QgsVectorLayer from memory: mem_layer = QgsVectorLayer("point?crs=epsg:32630&field=id:string","TempFile","memory") ...
2
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0answers
27 views

Modify CSV file in QGIS before joining it to a shapefile

I've imported a Delimited Text File that I want to join to a shapefile I have. Unfortunately, the join field attributes have a pesky ' character before the actual string. I wanted to delete that ...
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0answers
14 views

Recover failed raster calculator operation QGIS

Users can recover their raster calculator algorithms via the "results" panel in ArcMap (i.e., analogous to viewing one's "history"). Is there a similar function in QGIS? In other words, is there a ...
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0answers
18 views

How to calculate best path between 2 points from a DEM in Qgis?

I'm analyzing the roads and paths of a region by calculating how effective the communication is in the region. First I calculated the shortest paths between the points using the actual road map. Now ...
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0answers
49 views

How to use more cpu while processing in qgis

I'm trying to do some clip process with a quile large layers but the process is too slow. When I see the task administrator, just around 28% of the cpu is being used. I've tried with 32-bit and ...
3
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0answers
32 views

How to create a shapefile having Voronoi diagrams from the shapefile of an existing region?

I have a shape file of a region and I want to generate random sub regions of that shape file using Voronoi class of scipy.spatial package of python. But I am a newbie to GIS. I found out about Voronoi ...
4
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1answer
30 views

How to import a Composer Template into QGIS Print Composer?

How can I import a .qpt file into Print Composer (Composer Manager) in QGIS. I've tried saving it in the composer_templates folder but to no avail.
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3answers
116 views

How to create one shape file with categories?

In my QGIS 2.12.3 I want to create shape files of different lakes. I know how to do it one by one and this way, each lake gets a different color. But it should also be possible to create one ...
2
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1answer
37 views

Find all the values of a specific field of a layer based on location then select just those values to see where else they appear in the layer

I have a layer of property ownership in a county and need to see all the property owners in a parish [parish value already defined to feature in the layer] then see what other property those owners in ...
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2answers
39 views

QGIS 2.12.3-Lyon is unable open georefernced raster .png .tab files and says .tab is not a valid or recognized data source

I`m trying to Add Vector Layer-> Open Mapinfo File It's ok with map because it opened perfectly in Mapinfo application. What is the problem and how to fix it? I need georeferenced raster in qgis.
2
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1answer
30 views

Where can I find the version of scipy python package used in QGIS Lyon 2.12?

I am using QGIS Pisa 2.10. I want to use the Voronio class of scipy.spatial in QGIS python console. QGIS Pisa has 0.11 version of scipy package. This package doesn't have Voronoi class. I even tried ...
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0answers
34 views

Eliminate sliver polygons, not the enclaves

I would like to use the 'Eliminate sliver polygons' in QGIS, but only if they have the same attributes. To be more specific, I have an administrative shapefile that was created with the SEXTANTE tool ...
0
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0answers
29 views

OpenStreetMap doesn't show in map canvas in QGIS? [on hold]

I tried to download data via OpenStreetMap but it didn't appear in map canvas. Also, nothing shown in layers panel. Can someone help me?
2
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1answer
27 views

Extracting zeros from numpy array and creating a new raster

The following code reads in several .tif files from an input folder, converts them to numpy arrays and adds them together. All input files are binary: inputFolder = "/home/usr/Desktop/BufferFolder/" ...
2
votes
1answer
30 views

Rendering layer properties consistently in Print Composer in QGIS

I have created a layer of lat-long coordinates in the map I am working with that. On the map, I can appropriately size the "simple marker" representing each point for a given zoom. However, when I ...
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0answers
25 views

QGIS to tilemill export

does anyone know if there is a way to save a QGIS project in a manner that allows it or if there is a way to save a qgis project as mbtiles for use with mapbox
2
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0answers
26 views

How to match the colors of different RGB mosaic rasters?

I am beginner in QGIS. I want to classify many RGB rasters (see picture) but their colors don´t match. As you can see, the green polygon shows the same land cover class (meadow) but in each tile the ...
2
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2answers
62 views

Separate different zones from one attribute in QGIS?

I am new with QGIS and I use QGIS 2.12.3 Lyon. I downloaded from an official web side the protected water areas. Those areas are separated in different zones (for example zone I, zone II and zone ...
2
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1answer
28 views

Importing Several Raster Layers, Doing Manipulations and Exporting The Newly Saved Rasters

I have the following code: src_ds = gdal.Open("/home/usr/Desktop/RasterFolder/Name.tif") if src_ds is None: print 'Unable to open %s' % src_filename sys.exit(1) myarray = ...
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0answers
7 views

How to translate units to pixels for symbology rendering in Mapnik?

I would like to translate .QML-file to Mapnik .XML to render layer via Mapnik using the same style that is created for QGIS. The problem is that sizes and offsets on QGIS are defined in millimeters or ...
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1answer
30 views

Contour extraction from raster does not finish in Qgis. How to find out if a raster is damaged

Execution of "extraction" - "contours" in Qgis is impossible. The process never finishes, I stopped it after 35 min. The contour extraction works for all other raster files. I have tried with ...