Tagged Questions

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

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2
votes
1answer
46 views

How to open a compressed GDB in QGIS?

Looking for help with a problem in QGIS. I'm using QGIS 2.2 and 2.4 for potential analysis of surfaces. Data are based in gdb datasets that were created in ArcGIS and made ​​available to me. Some gdb ...
9
votes
5answers
284 views

GIS analysis to find duplicate geometries

I have a big shapefile that contains all the buildings and houses of the town that I work in (approx. 90,000 features). The data of the buildings/houses are saved by the town's surveying engineers and ...
3
votes
0answers
45 views

How to snap and move circles by the center?

I have a point layer, and a polygon layer with buffers of a given radius around each point. I need to move points, and check that each buffer is not above forbidden land/plots. In autocad, you can ...
2
votes
1answer
22 views

Importing a temperature raster layer to QGIS project

I am trying to add raster layers to depict minimum monthly winter temperatures for two counties in Ireland. I tried importing as tiff., ADF., HDR., and bil. files. I managed to add them in any of ...
1
vote
0answers
23 views

GPS with QGIS--what happened to the capture point?

I have been using QGIS for years but when v. 2 came out and important functionality seems to no longer work. In 1.8 the "capture point" or "capture line" buttons on the GPS panel would work. Ever ...
2
votes
1answer
26 views

How to make my PostGIS vector layer in QGIS visible?

I have loaded a shp file (simple polygon with one entry) into PostgreSQL 9.3 (with extention PostGIS v2.1.3). I now want to load this layer into QGIS (v2.2.0 Valmeira) via the "load Postgis layer) ...
0
votes
0answers
78 views

QGIS WFS Error - Could not commit changes to layer

I have a PostGIS database being served by Geoserver. I can load the layers I want into QGIS no worries; however whenever I try to edit the layer I get this error message: Could not commit changes to ...
2
votes
2answers
59 views

How to open the “File Browse” dialog in Windows from a PyQGIS plugin code?

I am in the process of developing a plugin for QGIS using Python. Note that this is my first plugin, so the query could be quite basic... I have used this Digital Geography link to create the basic ...
0
votes
0answers
27 views

Identify features button disabled

I am new to QGIS. I have installed 2.4.0 and opened up a .qgs file without problems. But the "identify features" icon is disabled/blacked out and not functioning. Please find screenshot below. Why do ...
2
votes
1answer
64 views

How to cut and paste polygons in QGIS so they don't overlap?

I use QGIS, and I need to cut and paste polygons so they don't overlap. Here's what I mean: I have shapefiles for cities that I'm pasting into a new polygon shapefile. I also have shapefiles for ...
1
vote
1answer
58 views

Update QGIS on Mac OS X

I would like to update QGIS from 2.2 to 2.4 on Mac OS X (10.8) but I cannot find how to do so. Do I have to uninstall and re-install all from KyngChaos? If so, I would therefore lose the extensions ...
1
vote
0answers
38 views

midpoint of segments in QGIS determination

Gene thanks for your note on the problem yesterday ... This is a follow up to a question I posed before (How to find the middle point of a line in QGIS - Where to place input file name). Errors coming ...
2
votes
0answers
34 views

Correct syntax for retrieving features from GML format in OpenLayers

Yesterday I made with qgis the shapefiles of my town and now I wanted to add them in a web application I'm making with OpenLayers. The problem is that, while it loads them perfectly with the wms ...
3
votes
2answers
124 views

Ripley's K function in QGIS Chugiak 2.4

I'm a noob user and I need to apply the Ripley's K-function on a point pattern in QGIS 2.4 Chugiak, but I don't know how to do. I think I need to use some plugin or extension (maybe GRASS, R or ...
9
votes
1answer
207 views

Can PostGIS and QGIS provide dependable multi-user editing?

After considering a few options, I'm trying to give my 15-20 QGIS 2.2 users the ability to concurrently view/edit one or two basic point PostGIS layers, largest one has just 16,000 records. I've ...
2
votes
0answers
38 views

QGIS There isn't entry in geometry_columns!

In PostgreSQL v9.3 with PostGIS v2.1 extensions I created a view from two tables (sites & visits). The site table contained a point geometry column (the_geom), which was included in the created ...
2
votes
0answers
55 views

QGIS atlas generation to make company expansion slideshow/video

I need to create ~98 maps each showing the locations of customers as a company expands over a time series. These will be made into a slideshow/video showcase so all maps need to have the exact same ...
1
vote
0answers
50 views

Is there a python function in QGIS to detect if the output file is saved to the hard disk?

I'm currently using QGIS 2.4 and writing some custom scripts on it. A proper script not only accomplishes its function, but also accepts user defined parameters and checks for possibilities of errors. ...
2
votes
1answer
48 views

QGIS crashing when using 'save as' to save a new projection

Every time I try to save a layer with a new projection using 'save as' my QGIS crashes. The new files are there but they seem false. Please see two screenshots attached, one before and one after I ...
2
votes
1answer
35 views

QGIS atlas-generation: Is it possible to preserve the map section?

My aim is to generate several maps with the atlas function in QGIS 2.4 (win7 64) showing the same map section and scale. However, each generated atlas map shows a slightly different map section (not ...
2
votes
2answers
108 views

Standard deviation classification in QGIS

Is it possible to implement Standard deviation classification in QGIS symbology of a layer like in ArcGIS: http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=Standard_deviation I need to ...
1
vote
0answers
24 views

Joined field not recognized as number in QGIS 2.4 [duplicate]

I have a weird problem. I've loaded in QGIS a point shapefile and a CSV table. Then I performed a join between the 2 layers and all works fine. But then the joined columns (made of integers or real ...
3
votes
1answer
164 views

OpenLayers plugin OverflowError: cannot convert float infinity to integer

OpenLayer plugin in QGIS 2.4 is not working properly when not loaded in first place. If I add an OSM map with the plugin immediately when opening QGIS, all goes well. But when I call the plugin ...
2
votes
0answers
37 views

How to find the middle point of a line in QGIS - Where to place input file name

I am trying to follow the python code below (How to find the middle point of a line in QGIS) to create midpoints of line segments in QGIS 1.8. I am receiving errors executing the code. Unfortunately, ...
2
votes
1answer
50 views

Adding new Field and writing values for all features

I need to create new Field in Attribute table of vector layer, and afterwards to calculate values and store them in that Field for all features I have in that layer. I have solution which works, but ...
2
votes
0answers
38 views

Batch export to shapefile by attribute field in QGIS

I have a project in QGIS where I am creating a map of plants over a large area. I want to take the "Genus" field (of which there are 100 hundred values) and essentially create 100 shapefiles based on ...
1
vote
0answers
34 views

QGIS OD matrix assignment on network

Using QGIS, I would realize an assignment of an OD matrix on a network, like this one on Transcad. I have: - network - points of Origin and Destiny - flows of traffic for each OD I found a solution ...
1
vote
0answers
47 views

QGIS Add WMS layer with python

I'm developing a stand alone python script using QGIS 2.2.0 libraries. I want to add a WMS base layer to my map, and I follow the instructions reported by the documentation: urlWithParams = ...
5
votes
1answer
47 views

Is it possible to have a 1:n join which takes the min, max, or average value?

I need to join the attributes of a shapefile with the one contained in a .dbf (or .txt) file. I currently use the "join" in the properties menu, but I have a problem. In the shapefile I have one ...
1
vote
0answers
23 views

QGIS server pie chart false rendering

I am currently working with QGIS 2.4 on Windows 8.1 pro and with QGIS-server on Debian 7. I want to publish a map with diagram but the render is not good. At right is the desktop map and at left the ...
0
votes
0answers
17 views

Using setCrsTransformEnabled in qgis 2.4

In the python console of qgis I try to load layers from shapefiles which have different CRS using the setCrsTransformEnabled() method. To test the procedure I changed the CRS of the shape file using ...
1
vote
0answers
40 views

How to periodically refresh QGIS display with updated shapefiles?

I'm creating updated shapefiles for a fixed set of layers in a project every 15 mins. If the user has that project open in QGIS on a Windows 7 PC, I can't overwrite those shapefiles, so I rename the ...
0
votes
1answer
33 views

Ubuntu QGIS 2.4.0 SSL connection to remote PostGIS fails b/c can't specify certificates

I can connect with SSL in PGAdmin to my remote server, but it requires specifying the filepaths for certificate files due to my having different certs for different servers. However, when connecting ...
6
votes
2answers
358 views

Using ArcGIS and QGIS together in multi-user editing environment?

We have a GIS staff of 7, and another group of about 14 who "use GIS" from time to time. We really, really want multi-user editing. Mostly of a large point file, and we're almost never in the same ...
0
votes
1answer
75 views

dealing with geometry that should be geography (bad coordinates)

I'm working on a project with a few publicly available datasets. One of them is from the USGS, it's their prediction of peak ground acceleration in 50 years. Here's a link, and here's what it looks ...
2
votes
2answers
56 views

Unable to merge CSV and CSVT with shapefile using QGIS due to “text” fields?

I know the question is all over this site, unfortunately I cannot find a solution. I have this CSV file and this CSVT file that I want to merge with this shapefile. I've tried to format the .csv using ...
1
vote
0answers
23 views

QGIS, drawing entity with a magnetized knot

I wanted to know if it was possible to draw with a magnetized knot, like Archi or Autocad ... !?
3
votes
0answers
55 views

How to create a python plugin in QGIS 2.4.0?

While I am learning to create a python plugin in QGIS 2.4.0, I have followed the proceedure expalined in ...
0
votes
1answer
49 views

qgis2leaf plugin & data defined properties style

I exported a map with data defined properties style from qgis2leaf, but it doesn't appear like the following map. Only dots appears on the openlayers map. Is it possible to visualize this kind of syle ...
1
vote
0answers
43 views

Clipping and reprojecting in one process for modelbuilder // “Save raster layer as” … in modelbuilder

I want to build a model in the QGIS Modelbuilder. First it should do a clip. Afterwards it should be reprojected (from Geographic WGS84 Coordinates to Gauss-Krüger). I only see one way to do this: ...
1
vote
0answers
40 views

using r.volume model GRASS plugin in QGIS

I am calculating volume of bathymetric data in the form of a clipped raster in GRASS with a Custom Lambert projection centered around 70degrees North, using the module r.volume in GRASS. Side note: ...
2
votes
1answer
36 views

Adding attributes to an existing shapefile [duplicate]

I have a shapefile made of buildings, each one of them characterized by some attributes. I need to add some attributes contained in a .dbf file. The two files have in common the attribute "ID", so the ...
1
vote
0answers
26 views

Should i use cell registered or grid registered bathymetric data in QGIS?

I am planning on calculating habitat volume over great ocean distances and have the choice to use either Grid or cell registered data, downloadable from this link. ...
1
vote
0answers
41 views

QGIS Freehand editing plug-in: blocked attribute table

I can't save object after drawing by Freehand editing plug-in. I suppose it will be connected with creating some (special) column in the table. Could anyone suggest a solution?
2
votes
1answer
61 views

How to properly open an ASTER data?

Yesterday i downloaded an Aster L1B image from USGS's website. If i load it in QGIS, it doesn't get displayed properly(location wise). Even after i've enabled "On the fly" option, it's not reading the ...
1
vote
0answers
19 views

PyQGIS: Properly trigger actionPan() tool when feature is added

I wrote a plugin which creates a custom map tool that adds features. I would like to cleanly connect to the pan tool after a feature is added. I've done it in the following way and it works, but I get ...
3
votes
2answers
64 views

Using SVG from Wikipedia to fill polygon?

I'm trying to use the flag of each region in Italy to fill each region's polygon. I have downloaded the shapefile of Administrative areas for Italy from diva-gis and am now attempting to fill each of ...
3
votes
0answers
30 views

Raising raster to a power gives no data values

When performing the following operation in QGIS Raster calculator: 10 ^ (("20091201_20100101_chl_modis_malvinas_ns@1" * 0.0000581)-2) I get no dada values for every cell where I should get < 1, ...
1
vote
0answers
27 views

Tables from SQL Server to QGIS Layers

I'm a beginner SQL and GIS user and this my first time using stackexchange, so apologies if I'm asking the question properly. I'm trying to open some MSSQL tables in QGIS. I established a connection ...
3
votes
1answer
38 views

How to refresh the view in QGIS Print Composer using Python?

I am trying to automate the printing of maps based on different attribute classifications using Python in QGIS. Everything is okay except for when I open the printed image, the labels are blurry. ...