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

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0
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1answer
29 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
3
votes
0answers
33 views

Extract the outer points of a Point Shape into a Line Shape? [duplicate]

I've installed QGIS 2.8.2 since a few days and have no experience with this application. I try to extract the outer points of a Point Shape into a Line Shape, like a shell for the inner points. All ...
1
vote
2answers
49 views

Topological errors after dissolve - how to avoid/get rid of?

After dissolving a layer in QGIS 2.8, I get a lot of topological errors in the new (dissolved) layer. Any suggestions as to how to get rid of these errors without manually editing each one? ...
3
votes
0answers
35 views

Trouble importing an QGIS ascii DEM file

The output I get from QGIS 7.0.1 for an ASCII DEM file doesn't seem to be a correct format. It differs from the format I get when I download a DEM file from webGIS ( ...
6
votes
2answers
226 views

Is there a way of mirroring layers on QGIS?

I would like to know if there is any way of mirroring layers on QGIS. My current project is a bit hard to explain... I'm excavating the inside of a large pot and, in the end I will have a set of plans ...
4
votes
1answer
50 views

Generate grid shapefile in R

I have the following shapefile of a 10x10 degree latitude/longitude grid that I created in QGIS. I can read it into R using the rgdal package. Grid<-readOGR(".","GridShapeFile") It has the ...
1
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0answers
46 views

QGIS printing shift on WGS 84 Pseudo Mercator base

I've had this problem before but I'm not succeeding in fixing it using what I thought worked before. This has been brought up as an issue previously, but I'm stuck when I apply the previous answers. ...
1
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0answers
41 views

Compile QGIS from source (with Grass)

I recently decided to reinstall QGIS and build against the latest version of GDAL - something I have been putting off for ages because I suspected it would be a nightmare. Lo and behold it has been, ...
2
votes
3answers
102 views

How do I upload a KML file into QGIS with the attribute data intact? It is present in Google Earth but not when imported into QGIS?

http://data.gov.uk/dataset/sites-of-biological-importance-sbi-in-greater-manchester-as-at-2015-04-28 This is the website which contains the data I need. I need to show the site names on my map, but I ...
-1
votes
2answers
51 views

What and Where are the best courses in GIS for a beginner? (Southern UK) [closed]

I use QGIS 2.8 for creating plans in my new job and would like to study how GISs work, pulling data through from databases etc. Any advice would be gratefully received.
2
votes
1answer
53 views

Processing algorithm fails from Python script

I'm trying to write a Python script performing a geoalgorithm. What is surprising me is the following: I first test the algorithm by QGIS (2.8) interface. In my case, the GRASS interpolator ...
1
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0answers
47 views

How can i add custom menu in QGIS Using python

I am tried to add a custom main menu in QGIS Desktop Application. Here I am already added custom sub menu in QGIS but I want to add a custom main menu in QGIS using Python. See the blow image.
2
votes
1answer
33 views

QGIS updated polygon areas

I'm using QGIS 2.6 and regularly update a shapefile layer to indicate felling progress. However, if I edit the nodes of a polygon, save the layer out then look at the Attributes table the area shown ...
5
votes
3answers
155 views

How to find and replace attribute values based on a list

I have a Shapefile and a list in .csv which contains two columns with names: "Old_name" which contains the old names that already exist in the attribute table of the previously mentioned Shapefile; ...
2
votes
1answer
38 views

The QGIS atlas defined with pyqgis and a QPT template exports the same maps

I need to generate an atlas for each feature from a layer for reporting. There will be created a few maps. The centre of each map must be focused on each feature. In this task I use a predefined QPT ...
5
votes
2answers
107 views

How to calculate with time values in QGIS?

I have two string fields in a vector layer, "From" and "To", with values in the format of 10:16:30 and 10:18:00 e.g. I would like to calculate the difference in minutes as a decimal value, in this ...
4
votes
1answer
153 views

Updating SRID (Update_GeometrySRID) does not alter polygons (when it should)

I am trying to change the SRID of polygons layer, but I'm having trouble visualizing the result. I the SRID is misreported the shapefile I used to import into PostGIS. The metadata says the ...
1
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0answers
41 views

Turning “normal” Vector Data into a GIS

I have a map in Adobe Illustrator with several vector layers. ( Therefore the vector data have no spatial reference and no attributes. What is the best way to turn these vector data into a GIS and ...
2
votes
1answer
44 views

QGIS re-write loop efficiently, assign number to every row of a column,

I have a column titled CompanyNam and I need to extract the ownership information. For example, if CEZ is the first company then, I assign to it number 1, then Sokolovska is the next number, etc. If ...
2
votes
1answer
27 views

Multiple display of vector layer in a qgis plugin interface

def initGui(self): """Create the menu entries and toolbar icons inside the QGIS GUI.""" icon_path = ':/plugins/cropEt/icon.png' self.add_action( icon_path, ...
1
vote
2answers
63 views

GDAL/QGIS broken Ubuntu 14.04

I think I've managed to bust GDAL after (I think) installing Grass7. I had previously built GDAL (1.10) from source with a bunch of additional drivers. When installing Grass7 GDAL 1.11 was installed. ...
2
votes
1answer
39 views

QGIS set all layers with custom transparency with python?

I'm exploring QGIS python functions to set all raster layers with a custom transparency, i.e 0,0,0,100 . Looking at some previous questions. There is a way to loop all the layers, but the aspect to ...
1
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0answers
27 views

QGIS 2.8.1 running error

I am using QGIS 2.8.1-wein 32bin version. When running QGIS, It does not open. After displaying like below the picture, nothing happen. If you can solve this problem, please give me a solution. (I ...
3
votes
1answer
66 views

Split raster into tiles

I have a raster that needs to be split into tiles (each tile a new raster). I have a Shape file with multiple polygons (these polygons are how I want the raster split). I have Gdal and QGIS. Any ...
2
votes
0answers
32 views

Zonal statistics error: 0-d arrays can't be indexed

How can I fix the error 0-d arrays can't be indexed? This message appears after the tentative to use the algorithm Qgis Zonal Statistics. Detail: the algorithm worked very well several times and then ...
2
votes
1answer
36 views

how can I get the majority (dominant) class of a raster to an area (polygon) using qgis?

I have a vector layer with many basic units of planning (zones), a raster layer with three classes of geology and other raster layer of geomorphology with five classes. How can I update the ...
2
votes
1answer
36 views

QGIS crashing/failing when dissolving multiple shapefiles in a Python loop

I am using QGIS 2.10 (but I've also tried 2.8) to loop through all the shapefiles in a folder (those ending in .shp) and perform a dissolve function on each of them. However, when I run the following ...
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0answers
28 views

How does NULL data effect weighted mean calculations?

I am using QGIS. I've been calculating weighted means based off a database. The database was created by combining two different sets of Data together. The Attribute Table then shows Null values for ...
1
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0answers
20 views

Geometry Calculation in QGIS [duplicate]

I'm trying to calculate the area of some census tracts in qgis I go to vector -> geometry tools -> export/add geometry columns in the resulting dialog, I calculate using project CRS. What comes out ...
1
vote
0answers
42 views

Why does every raster calcuation I try return with NAN values?

I am trying to work with DEM rasters from the USGS using the raster calculator. I have tried to change the units from meters to feet using an expression such as: "ned10m45111h8@1" * 3.28 However ...
1
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0answers
40 views

How to define a custom function that returns value of a field in an unsaved form

Filter expression builder in QGIS 2.8 allows us to define custom functions using python. I'm intrested would it be possible to define a function which returns a value of a field in an unsaved form ...
2
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0answers
28 views

QGIS empty date field shows value in custom form

I'm trying to define custom form. Problem is with date field- form shows value even if it's empty. Is there a way to set it to show only the existing values?
0
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0answers
40 views

Does Processing plugin v2.10.1 not recognise SAGA?

Version 2.9.3 of the Processing plugin works fine, I can run the SAGA tools successfully. Updating the Processing plugin to version 2.10.1 results in SAGA disappearing entirely from the toolbox. The ...
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0answers
28 views

unable to use matplotlib in qgis using python

I have tried to draw graph using matplotlib i used this library in my qgis application but i got the error ImportError: No module named backend_qt4agg i used following code in my qgis python ...
1
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0answers
37 views

SAGA tool 'Relative Heights and Slope Positions' - What do results tell me?

I am currently trying to get in morphometry, using the SRTM 30m DEM. I was recommended to test the SAGA mudule 'Relative Heights and Slope Positions' ...
1
vote
1answer
84 views

Ranking Elevation using QGIS?

Can QGIS automatically find the lowest land-point in a country and when you would like to, find the second lowest, third lowest land-point and so on? And on that same coin, a software that could find ...
1
vote
1answer
55 views

How to link a pdf file to a specific feature with QGIS? [duplicate]

I'm trying to link a pdf to a parcel (see image: http://imgur.com/RbauB3v) where you click on one parcel and a specific pdf comes up and if you click on another then a different pdf comes up. I've ...
1
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0answers
21 views

What does “Information [18]: Select at least one signature” in the semi automatic classification plugin mean?

I am using the semi automatic classification plug in to classify vegetation and water in a satellite image. I create training shp and signature list. When i hit "classification preview" it gives me ...
0
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0answers
19 views

Allocation of data by Voronois to admin units according to area in QGIS? [duplicate]

In QGIS, I need to assign values from Voronoi cells into admin 2 units (e.g., counties) with a weighted average according to the amount of territory of each county covered by the cell. So, for ...
0
votes
2answers
45 views

Spatial join geotagged images to preexisting point shapefile?

I have a layer of geotagged images (points with jpg thumbnail attachment), and another layer of different points (shapefile with various attributes). I would like to perform a spatial operation in ...
0
votes
1answer
22 views

Error during building an application c++ using api qgis 2.8

I have an apllication that need an object the object type is QgsSymbolV2 but i cannot do that : QgsSymbolV2 * lSymbol = new QgsSymbolV2(); because in the class qgssymbolv2 there is no constructor ...
2
votes
0answers
24 views

QGIS: distance matrix different outputs

In one of my plugins I would like to use the distance geoprocessing algorithm. When running this algorithm from the menu Vector->Analysis Tools->Distance Matrix I get a different output than running ...
0
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0answers
32 views

Problem with calculating slope in QGIS

Ive downloaded DEM form earthexplorer. But after calculating slope I only have blac img. with same value in min. and max. When calculating aspect or relief, DEM works correctly. Have you met with ...
1
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0answers
38 views

Data Upload Error for QGIS Cloud

I'm just taking a stab at QGIS Cloud to investigate it for a potential client, and I am pleased with the functionality of the web-viewer based on the sample maps. Although I cannot upload my own data. ...
1
vote
1answer
57 views

Efficiently Calculating Farthest Point from Origin

I'm trying to find a clever/efficient way to calculate the the farthest point from an origin, given a list of lat,lng points. For example, if trying to find the closest point from an origin I could ...
2
votes
2answers
65 views

How to create a zoomed in portion of a map in print composer?

I posted a question yesterday about troubles I was having with labeling (which are still plaguing me), but it hit me today that it would probably be easier for me to just create zoomed in sections of ...
3
votes
1answer
49 views

Point Coordinates Conversion with unknown system

I've been using QGis for few weeks now. Although this site always came very helpful, I can't find solution to my recent problem: I have few points, and know their coordinates in "WGS-84" and "ISN-93" ...
1
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0answers
17 views

Replacing white or black by alpha channel in raster in QGIS 2.8

I'd like to replace black or white in black and white raster in QGIS 2.8. I perceived that in some other raster where "nan" value automatically occurred and only white or black is being displayed.
3
votes
1answer
40 views

OpenLayers Plugin - Opencyclemap does not display correctly

It happened on version 2.6 and I was told it was my version that was the trouble, so I reverted to 2.2. The odd thing is, that it will usually work fine the first time I open the map, but it seems ...
1
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0answers
12 views

where are old function of qgssymbol

in the new version of qgis 2.8, in the c++ API and in the class QgsSymbolV2, a lot of function has been deleted, by exemple setfillcolor, setcustomtexture, setnamedpoint, setpointsize i would like to ...