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

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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") ...
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1answer
34 views

Building QGIS 2.8.6 on Win 7 32bit?

I'm trying to build QGIS 2.8.6 on Windows 7 32 bit using MSVC Express 10. The build process completes without errors, but with a bunch of warnings. When I run the qgis.exe after installation, it only ...
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0answers
6 views

QGIS Download getting stuck, NSIS error?

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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12 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 ...
2
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0answers
16 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
27 views

How to avoid field duplication when joining two vector layers?

I have 2 point vector layers wich differ in 2 fields while both of them have the same number of fields (10). What I want to do is produce a new point vector layer with 12 fields. When I join the two ...
2
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1answer
41 views

Create default QGIS actions / define my own default actions

I have created a simple action that should be used to several users. Then, I'd like to put my action among their default action list. Put it simply, how can I create a default qgis action in a given ...
1
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1answer
33 views

error when merging geotiffs

I have a problem with a actually simple task: I want to merge 12 Geotiffs in QGIS. With Raster => Miscellaneous => Merge there is always an error saying: xyz.tif does not exist in the file system, ...
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 ...
2
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1answer
4k views

How to convert a finished project in QGIS to PDF

I have finished my project and need to convert it into a PDF file. How can I do it?
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0answers
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 ...
3
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1answer
62 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 ...
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3answers
2k views

How to enable multithreaded processing in qgis 2.2

I have found multiple links that appear to say that this now exists in qgis 2.2, but it appears that it's only using one core to full capacity. This is running on Ubuntu 14.04 The current process is ...
3
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1answer
21 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.
2
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1answer
406 views

Maximum scale dependent visibility changes from 1:0 to -2147483648:1

QGIS 2.0.1 Dufour. When i open the layer properties and the scale dependent visibility is unchecked and when i check it, the maximum (inclusive) shows 1:0. I click Apply, OK, reopen layer properties ...
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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 ...
3
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4answers
7k views

How to export attribute table to Excel from QGIS?

I have seen all the questions for this question, and I try all the answer like copy paste, csv (in fact this I don't know where to find) but none of all is not the right answer. Can anyone help me?
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0answers
38 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 ...
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 ...
3
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0answers
24 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 ...
1
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3answers
104 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 ...
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0answers
19 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
32 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 ...
2
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1answer
22 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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2answers
67 views

QGIS: drag zoom via keyboard shortcut/ mouse wheel?

To zoom to a rectangle in ArcGIS, I always clicked and held the mouse wheel while pushing the control key. This was a very efficiant way for me to navigate through a map. Is there anything similar in ...
2
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2answers
62 views

Update field based on spatial query (QGIS)

I was an intermediate user of MapInfo and have recently converted to QGIS. I would often use MapInfo to add a column in boundary file A saying which zone in boundary file B it is contained in. ...
5
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1answer
106 views

How to cartographically generalise buildings/settlements in QGIS?

I have a set of buildings in a polygon layer which I'm going to use in a 50k map. Since the buildings are tiny I cannot show the actual form of the building, instead I'm taking the centroid of the ...
1
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2answers
86 views

How to get ST_MakeLine ready for QGIS?

CREATE VIEW new_line AS SELECT point1.gid, ST_MakeLine(point1.geom, point2.geom) FROM point1, point2 WHERE point1.gid = point2.gid; It's possible to load the layer but QGIS says 'There is no entry ...
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0answers
24 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 ...
1
vote
2answers
391 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 ...
7
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1answer
193 views

How to connect centroids of lines sharing the same intersection in QGIS?

I'm looking for a big help to accomplish the following task: I have this street network of the center of Turin (IT), composed by lines representing streets, and black points representing ...
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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?
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1answer
256 views

PopUp with Images with QGIS2web

is it possible to create popups with images via QGIS2web? if yes, what would be the workflow? Couldn't it figure out yet. So any help is welcome! Thanks
2
votes
3answers
259 views

QGIS - Geocoding addresses to coordinates

I've got an Excel file which includes known locations with their exact address (street, house number, city, state). This Excel file does not have a geographical column. Also, I have a .shp file inside ...
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 ...
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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
21 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/" ...
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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. ...
2
votes
1answer
82 views

Concatenate or group by values using spatial join in QGIS?

I have a layer (SQLlite) of city lots and would like to accomplish the following: For each city lot, concatenate the list of unique lot id's which are bound within a radius of 30m from the given ...
1
vote
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 ...
8
votes
1answer
135 views

Simplify repetitive tasks in QGIS Graphical Modeler

Are there iterators that can be used in QGIS graphical modeler to simplify the model shown above. If not, is there any better way of simplifying the model? The first column represents my input ...
3
votes
1answer
219 views

Is there a decent algorithm in QGIS Process Modeller to create a grid?

I am using Process Modeller to automate merging several vector layers and then creating a grid to cover the extent of the merged layer. There are functions which already exist which are not listed in ...
12
votes
2answers
4k views

How to concatenate labels in QGIS?

I'm using QGIS 1.8 on windows XP machine and I try to do a concatenation of several fields to label the names of my local roads in the attribute table, but I can not find the correct syntax. The first ...
7
votes
1answer
119 views

Join by attribute / spatialite with SQL / left outer join in QGIS

I have a layer with polygons (let's call it "woods") that is intersected by "n" line-objects ("roads"). Every road has an unique attribute roadid. I need to add ALL the roadid's (not only the first ...
1
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1answer
22 views

QGIS Composer value based on http request param

is it possible to set value in QGIS Print Composer based on HTTP request param? For example i want to add table in composer with something like "value = $requestedvalue", and $requested value should ...
2
votes
1answer
22 views

QGIS Server sending UPDATE… WHERE NULL to postgis in a WFS layer

I am running a Windows Server 2012 server. PostgreSQL 9.3.5, 64-bit POSTGIS 2.1.3 QGIS Server 2.6.1-2 QGIS Desktop 2.8.3 and 2.12 I am using a Microsoft Surface Pro 4 tablet using QGIS Desktop ...
2
votes
2answers
59 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
votes
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 ...
0
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1answer
26 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 ...
2
votes
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 ...