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

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3
votes
1answer
51 views

Importing large .asc files into QGIS

I've been given two .asc files containing a 1m raster data from a LiDAR survey. I only have access to QGIS.2.14.1 (which I'am using for the 1st time only having previous experience with ArcGIS) and I ...
0
votes
1answer
23 views

Comparing areas of overlapping shapes in QGIS

Given SHP files for a country's Districts in Year1 and Year2, how to output a table whose rows state the percentage composition of each Year2 District in terms of portions of Year1 Districts
0
votes
1answer
16 views

R.patch creating enormous file size

I'm using r.patch (within QGIS, GRASS 7) to patch two Float32 rasters both of which have a respective filesize of under 200MB. When I save the memory layer raster created by the r.patch function, the ...
4
votes
1answer
44 views

Positioning of graticule labels in QGIS 2.14.1

I have a map grid (line, shp) that was created with MMQGIS. The X and Y coordinates of the lines are stored in the the attribute table, which makes labelling the lines an easy process. My problem is ...
2
votes
0answers
47 views

QGIS managing relationships

Coming from an ESRI background I'm used to ESRI geodatabases (.mdb or .gdb). In those databases, I could create feature classes, tables and relationships between them. Every time I loaded a feature ...
1
vote
1answer
66 views

How to digitize 3D geospatial data using FOSS applications

I need to digitize soil horizon data from photos to be later used in a 3-dimensional GIS workflow. For each photo I have DGPS coordinates of the top left and right corner and the depth of the ...
3
votes
1answer
68 views

Application of preset properties QGIS layer to another imported shp

In QGIS I import the same shp files during days (continuously fieldwork). For processing in QGIS I set the properties of layer (imported shp)- Style, Labels, Actions, Display. In these days I have to ...
2
votes
3answers
68 views

Merging tif images into a single GeoTiff with QGIS

For this example, I have 3 tif images that are tiles. They fit together to form a single image. I load the 3 images into QGIS and it merges them directly and I see my completed image. The problem ...
1
vote
0answers
24 views

QGIS “buffer” considering grades

I have to develop an article entitled as "GIS IN ASSESSMENT OF BUS TRANSIT SYSTEM ACCESSIBILITY CONSIDERING GRADES". I'm still at an early stage of development of the research project, but I have ...
2
votes
0answers
22 views

PyQGIS: intersection of one node layer with two polygon layers

I´m new with the use of PyQGIS and I´m working in a problem applied to a water supply systems modelling, where I need to distribute the water demand in about 5000 nodes (network junctions). I´m ...
2
votes
0answers
14 views

Issue loading PostGIS out-db rasters (either in QGIS or MapServer)

I'm playing with a few different options of storing raster data via PostGIS to visualize (eventually in a web app). The out-db or out-of-database storage seems the best option, but I can't seem to ...
1
vote
1answer
21 views

qgis feature classification of filegdb datasource bug?

When I am trying to create a symbol classification from a filegdb datasource in qgis the list of unique attribute values is not being populated when I hit the 'Classify' button. It loads a single ...
3
votes
1answer
29 views

How to keep live update coming from a WMS

I'm using a WMS that contain weather radars that is update every 10 min. I would like to know how to keep the map updating every 10min. I tried: from PyQt4.QtCore import * timer = QTimer() ...
2
votes
0answers
12 views

Why does QGIS try to create spatial tables when loading into MSSQL Server?

When trying to load a layer from the QGIS layers panel or browsers panel, errors pop up that either the 'spatial_ref_sys' table or 'geometry_columns' table exists: If these tables exist already, ...
1
vote
0answers
28 views

Error with SAGA's Topgraphic Correction

I am using QGIS 2.14.2, trying to perform a supervised classification on a rapideye image with the SCP plugin. To improve my classification im trying to work with the SAGA's topographic correction. ...
1
vote
1answer
21 views

Using Title Case on Everything Except Last 2 Characters

I have addresses in my attribute table that I converted to title case from upper case. Example: 123 FAKEVILLE ST NW to 123 Fakeville St Nw How can I make it so that the last 2 characters in all ...
2
votes
0answers
33 views

Unwanted display of 180 meridian in map [duplicate]

When I use the WGS 84 CRS the Chukotka peninsula east of the 180 meridian is shown on the left of the map. If I project (on-the-fly) the map using a Lambert Azimuth projection, the Chukotka peninsula ...
1
vote
0answers
22 views

Raster Precision QGIS

I am using r.patch extension in QGIS to join a number of LiDAR tiles, some of which overlap hence i am carrying out this task before utilising in a hydraulic model. R.Patch works fine, however the ...
1
vote
0answers
27 views

Help with Python shapefile Union Program

First I am a Python noob... I have searched the database for this answer, found a few that might be the answer, just way over my head (I am signed up for a intro python class this month, to help ...
2
votes
0answers
28 views

MODIS Imagery Orthorectification (Open Source)

I am looking for an open source free software/tool for orthorectification/Geometric terrain correction of MODIS imagery. I have looked at ESA (European Space Agency) SNAP but this sensor type is not ...
2
votes
1answer
43 views

QGIS: How to modify the appearence of selected attributes [duplicate]

I am using QGIS version 2.14.1 (Essen). When I open the attributes table of a layer, I select some data which is then highlighted in yellow on the map. I was wondering if it is possible to change the ...
2
votes
0answers
43 views

Update Join Attributes by Location

I have a shapefile with points, and a shapefile with polygons. I want to sum the attribute value of all points that are contained in a polygon, and I'd like to do this for each polygon in my dataset. ...
1
vote
0answers
36 views

How to incorporate QGIS custom widgets into plugin? [duplicate]

Developing a plugin with Qt Designer for QGIS 2.14.1-Essen on Windows 7 and having trouble inserting the QgsCollapsibleGroupBox widget. I receive the following error: ImportError: No module named ...
1
vote
1answer
28 views

QuickMapServices It is not for ubuntu?

I'm new using QGis. I read somewhere that QMS was better and more stable than the OpenLayers complement to use Google Maps. My problem is that it does not appear when I search with the plugins ...
-1
votes
0answers
29 views

Calculating total area overlapping raster DEM color interval whose boundaries are confined by another vector? [duplicate]

Example: I tried running raster calculator on intersections then zonal statistics checking "count" and "sum" but I get a huge table of 8000+ rows and two columns, however each cell usually have a ...
3
votes
1answer
37 views

Convert fields of points into separate polygons based on their outlines

I have several fields of points that look like so: They are actually thousands of points that appear as polygons because they're so close to one another. They're research points 720 feet from one ...
5
votes
0answers
30 views

QGIS Renders Buffer Polygons from ArcGIS Feature Class Differently

I have a polygon feature class stored in an ArcGIS geodatabase. All of the shapes are buffers of a point layer created using the editor menu's 'Buffer' command. In ArcMap 10.3.1 the data looks like ...
4
votes
2answers
56 views

Issue with QGIS 2.10.1 Clip and Intersect Tools

Having an issue in QGIS 2.10 -- clip and intersect don't seem to be working correctly. I am trying to show zipcode by a legislative district in Florida. When I clip the zipcode shapefile by the ...
2
votes
1answer
70 views

Styling a heat map based on point attribute, not density

I have a point dataset generated from getting the centroid points from a fishnet/polygon grid. I combined these points using a spatial join to give them an attribute of 'pressure' which is an integer ...
2
votes
0answers
29 views

QGIS Broken Link to files on a server

My colleagues and I are using different versions of QGIS (2.8.2, 2.86 & 2.14) on windows 8.1 and Windows 10. When we open existing projects we get a "Handle Bad Layers" box coming up. We have ...
2
votes
2answers
43 views

QGIS Segmentation fault when manipulating QgsGeometry

So I am running QGIS 2.8.1 on Ubuntu 14.04. This following problem is happening in my script, but also occurs directly in the QGIS python console: lay = iface.activeLayer() lay.featureCount() 1L ...
3
votes
1answer
44 views

Match polygons of two independently created shapefiles to create dataframe

I have two independently created shapefiles A) shapefile 1 lists the german postal codes and can be downloaded from ...
1
vote
0answers
27 views

Geoserver provide wms without authentication

I'm trying to understand how can add a layer from my geoserver without have to basic authenticate. The problem is when in QGis i try to add a wms layer and i put as URL as ...
2
votes
1answer
56 views

How do I get all the labels to show when they have exactly the same grid reference using QGIS?

I map species records using QGIS 2.14.2. Many of the records have been submitted with exactly the same grid reference for different species. This can up to twenty records (labels). But QGIS will only ...
0
votes
1answer
49 views

Exporting Raster from SAGA and importing it to QGIS - error CRS was unidentified

I make raster files from LiDAR las files in SAGA - CRS of .las is Slovenian national Grid. Then i export it as GeoTiff (Import/Export - GDAL/OGR - Export GeoTiff). When i import it into Qgis (Project ...
8
votes
1answer
168 views

Setting a default value in a QGIS field

I would like to add in a layer's field a default value. I mean, every time a new feature is created, that field would be automatically filled with the default value. In my case the default value ...
4
votes
1answer
58 views

Errror using the Simplipy QGIS plugin: 'QgsRasterLayer' object has no attribute 'selectedFeatureCount'

I am adding a raster in QGIS 2.14.1 and get this new error: AttributeError: 'QgsRasterLayer' object has no attribute 'selectedFeatureCount' I am not programming, just using a QGIS menu. I am using ...
1
vote
1answer
35 views

refresh programmatically created composer

I am trying to create a composer using pyqgis. Everything works as expected. The only difference compared to the manual creation of a composer is, that I am not able to update the layers (by pressing ...
0
votes
0answers
33 views

SRID and lat long values

I am using the following query to generate the lat long values SELECT NAME, ST_X(ST_Centroid(ST_Transform(geom, 4326))) as longitude, ST_Y(ST_Centroid(ST_Transform(geom, 4326)))as latitude from ...
1
vote
0answers
18 views

Linestring segment completition?

I just extracted some river paths from some old maps I acquired a few weeks ago, they seem accurate enough and will be very interesting to put against my theoretical mapping calculated by using the ...
6
votes
1answer
128 views

Memory Leak when deleting a layer

I am working on a project based on QGIS API c++ 2.8.2 and qt4.8. I have two methods in a class, the first create a layer and add a point Here is the code for the creating: LibCartoError ...
6
votes
2answers
112 views

Is there a way to assign row number for sorted table by column in QGIS?

Field calculator has a great function under "Records" called "$rownum" which returns (assigns) the number of the current row. Is there a way to make it work together with sorting? Lets say I want to ...
1
vote
1answer
13 views

How to open .jp2 with GRASS 7.0.3

Does anyone know if I can use Grass to open a .jp2 image file? I am aiming to do some image classification on the image and when I try to import the image into the program a stream of errors comes up ...
1
vote
1answer
51 views

Complex QGIS Relations

I need QGIS to display combo boxes when editing for certain fields in a table, very similar to the functionality provided by the Relations properties in the project settings. It seems this is ...
2
votes
0answers
37 views

QGIS, connect to postgresql using windows login credentials

How to connect QGIS to PostgreSQL/PostGIS using the Windows user login credentials (Windows / Active Directory / LDAP). Is it possible? Can anyone tell me how?
1
vote
0answers
40 views

OS X Yosemite: copy / paste into shell GRASS 6.4.4. within QGIS 2.14.0

I want to know How to copy/paste into GRASS 6.4.4. shell within QGIS 2.14.0. I'm working with OS X Yosemite and the right mouse button doesn't work neither shortcut (cmd+c/cmd+v)
3
votes
0answers
78 views

Inset map in print composer shifts when saved as pdf [duplicate]

I'm working on a map in the print composer window of QGIS, with an inset map showing a larger extent and highlighting the area of my main map as an overview. Everything looks good in the print ...
2
votes
2answers
45 views

Copy DEM attributes to a vector point?

I have a point that I drew on a tiff DEM file in QGIS. The point doesn't have any information in the attribute table except an ID of 1. How can I make it copy the raster information based on the ...
3
votes
1answer
35 views

Encryption of spatial data, GIS access and cloud synchronization

I'd like to encrypt a folder of many spatial datasets (rasters and shapes) because my office computer is shared with others. I've never used this kind of security but I think I should preserve my data ...
2
votes
4answers
78 views

merge overlapping polygons with spatialite

The green points, buffered by one of the point attributes, should result in the three areas outlined in red (a table with three rows): I'd like to do it in spatialite. How can I do that? If it's ...