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

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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
7 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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0answers
5 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
11 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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0answers
17 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
17 views

QGIS: 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
18 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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13 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 ...
2
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0answers
12 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
40 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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25 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 ...
3
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1answer
23 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
106 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
33 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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23 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
23 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
26 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 ...
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0answers
24 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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0answers
22 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/" ...
1
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1answer
26 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 ...
1
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0answers
24 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
20 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
60 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
26 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
6 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
28 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 ...
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0answers
27 views

GIS and RS reports auto-generation [on hold]

I need an open source tool package /Plugin for auto generation an interactive GIS and RS reports using a predefined templates. What can you recommend?
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0answers
20 views

Loading GML schema file on QGIS

I am Very New to GML format. first of all, I have came to the assumption that a schema file will display gml in a particular style as defined by the schema, similar to the way i load a .qml on a ...
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0answers
20 views

QGIS and GRASS 7 integration [duplicate]

I want to integrate QGIS 2.12.3 or 2.13 with GRASS 7, but I still haven't been able to do so. Can someone please tell me how can I do this with a stable QGIS version.
1
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1answer
19 views

Keep “no data” tiles as “no data” w/ proximity (raster distance) operation

Working in QGIS 2.8.1 Wien. I have a raster file with three classes: "No data" for tiles outside of the country of interest's bounds "0" for tiles that correspond to roads "1" for all other tiles. ...
2
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2answers
28 views

Keep “no data” tiles with r.reclass rules

Working in QGIS 2.8.1-Wien. I want to reclassify a raster with the r.reclass GRASS 7 tool, but want to keep the "no data" tiles as "no data". I understand that I need to create a text "rules" file ...
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0answers
16 views

Can OpenOffice database files be imported into iTree in lieu of mdb files [on hold]

can odb files work in place of mdb files for data input into iTree?
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0answers
23 views

Singlepart to multipart not producing results [on hold]

I have a line - a street downloaded from OSM. It is in separate parts geometrically, but is contained in one record in the attribute table. That means it is only one row. I would like to split this ...
1
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0answers
20 views

In QGIS add new attribute table features from updated csv [duplicate]

In QGIS I created a point layer from a csv using "add delimited text layer" (the comma icon). I set style and viewing scales the way I want for the layer. Since then the csv has been expanded with ...
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0answers
13 views

QGIS: Points in Polyon with two different CRS [duplicate]

I'm relatively new to QGIS. I've got a layer that shows the boundaries of the wards in the UK. In addition to this, I've got a csv file, which has long/lat plus an answer (binary). The problem is, ...
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0answers
19 views

My OSM country roads network is not routable [duplicate]

I need a routable shapefile in order to execute pgrouting algorithms. I download a national zip from http://download.geofabrik.de/europe/greece-latest.shp.zip and import the roads shapefile in my ...
2
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2answers
38 views

replace records in layer with records form another layer by id and column name QGIS

I have a two polyline layers - one with 2800 rows, the other with 150 rows. Each row has a unique id column. I need to replace the records in one column of the the 2800-row layer with the records ...
3
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1answer
61 views

Is it possible to change the legend so the symbol is on the right side?

Is it possible to change the legend arrangement so the symbol will be in right side and the label description will be in the left side? The QGIS default is label description in the right side and the ...
1
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1answer
28 views

Can I consider QGIS OpenLayer basemaps as WMSs?

I am writing a manuscript about QGIS, and I categorized the data types into 3 classes according to popularity (raster, vector, web-data). Then I separated web-data to WMS and WFS. Under the heading ...
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0answers
53 views

Can anyone suggest me interesting projects using gis software- advanced? [on hold]

I know this is not a question specific to the software. But I was wondering if anyone can help me find a project that can help learn qgis and gis as a whole as learning from tutorials is quite boring. ...
1
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0answers
26 views

Join Attributes By Location inside QGIS modeler still fails to compute sums

Recently, a question was asked about the spatial join tool, and its failure to calculate the desired data. I ran into the same problem, but none of the solutions that were offered there solved it. ...
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0answers
38 views

How to modify the QGIS software? [on hold]

How can change the word Save when you hover on the saving button in the QGIS software to Saved ?
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1answer
39 views

Add lat/lng to Shape File [duplicate]

I'm new to GIS. I have a shape file (shp) that I need to add lat/lng coordinates too. I used QGIS to open the file and selected Processing->ToolBox->QGIS geoalgorithms->Vector geometry ...
4
votes
1answer
64 views

basin creation GRASS vs. flow direction

I have a strange behaviour in QGIS with GRASS tools. I am trying to create basins in the alp region and use he SRTM3 data. As I can see on the flow direction raster the SRTM3 data seems to act nice: ...
3
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1answer
63 views

How can I create an average/center line in from multiples lines?

I have some polylines. The origin of every line is the same and I would like to obtain the geometric centre of all the lines represented by a new polyline which must be the centroid of the lines. How ...
3
votes
1answer
37 views

How to derive a hydrologically correct DEM from point shapefile using QGIS?

I used grass gis v.surf.rst function to interpolate a surface using vector points. But it is very difficult to find a optimum parameters to be used. I am still unable to develop a accurate terrain
3
votes
1answer
21 views

MMQGIS plugin causes QGIS crash while geocoding

When trying to geocode data with MMQGIS pulgin (Google Maps) the QGIS crashes (not responding). I even tried to divide data into smaller sets but it does not help.
3
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3answers
56 views

How to create a line with all attribute information of the original GPX points?

I am trying to make a shapefile line contain all the data that the GPX file has. So i load the gpx file into Qgis, (prompts me for tracks, waypoints, trackpoints, routes, etc) When i choose ...
5
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1answer
88 views

How to build a query/expression to select specific points within a buffer? (in QGIS)

I have a point layer in QGIS. Each point represents a tree and each tree has information about its height as an attribute. I would like to build a query/expression to select all those trees that have ...
1
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1answer
23 views

export more than one but not all attributes with qgis2web

Using the qgis2web plugin: Is it possible to select more than one but not all attributes to be shown as popup? I can select all attributes or only one attribute to be shown. but not for example two ...