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

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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
35 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
40 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
46 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
22 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
16 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
31 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
351 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
71 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
51 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
54 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
42 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
39 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
35 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
40 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
58 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
18 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
63 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
29 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
35 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. ...
5
votes
3answers
69 views

Create a Raster file out of a ASCII grid file?

im using a special system to do geomagnetic surveys. Its software let me output the information as image files, ASCII or in its own proprietary file format. Now i want to get its information in my GIS ...
1
vote
1answer
43 views

How to use the % Modulo operator to select points for labeling?

I have a shape file with point numbers for individual ID's. I would like to select point numbers divisible by a number, and if the remainder is 0 then I would like to label that point. I have tried ...
1
vote
0answers
13 views

How to add an unknown CRS to QGIS? [duplicate]

I wonder if there is an option to add a CRS to QGIS which is not listed in the internal database of the program. I read that PostGIS allows adding a custom CRS.
3
votes
1answer
167 views

How to install open layers plugin on QGIS 2.4? [duplicate]

I am a new user of QGIS, and I just downloaded the version 2.4 on Windows 7/32 bits. And I seem to encounter several problems: I cannot install openlayers plugin In the "Plugins" tab under "Manage ...
2
votes
0answers
53 views

How to merge overlapping and duplicate lines from vector layer to one single line?

I used the "polygone to line" tool from QGis, to get a line-layer from this polygon-layer: unfortunatly this causes overlapping and duplicate lines, after I broke the qgis-export via GRASS into ...
2
votes
0answers
35 views

QGIS “Fill Ring” tool error on SpatiaLite DB?

I´m try Fill Ring tool on a SpatiaLite DB and I get a error on the Primary Key. The Primary Key is integer auto increment. When I insert the ring and try to save editing I receive error message ...
0
votes
1answer
24 views

trying to calculate volume using r.volume GRASS - error message

I am trying to calculate volume using GRASS plugin in Qgis using module r.volume however the attached error message keeps appearing. Any ideas?
0
votes
0answers
24 views

Export qgis vector layer to PostGIS table using python

I've created script, which does bunch of stuff, and in the end, I would like to export it to postGIS table. What is easiest way to do such export using qgis api or sth. I dont want to write SQL ...
3
votes
1answer
29 views

How to define custom projection EPSG:5714 in QGIS

I have a series of raster files with the CRS EPSG:5714. I need to define this CRS in QGIS but I'm fairly new to this and have no idea how to define the proj4 CRS for this. I searched at ...
4
votes
2answers
164 views

How to save .shp to .csv so that the Name is in the first “column” of the .csv?

I am trying to convert a point shapefile to .csv with locations in QGIS. The problem I am having with the conversion is mainly that, in the resulting .csv file I would like to have the Name and then ...
2
votes
1answer
31 views

How to save the edit widget setting in a style or layer definition file?

I am using QGIS 2.4 on Windows 7 installed by the OSGeo4W-installer. I want to save the "edit widget"-settings in a style to use them after loading in a different vector layer. The problem: If I ...
3
votes
2answers
55 views

Calculating flowpaths downstream of a point

I am assessing the flood risk posed by pipeline failure. I need to calculate the likely flow-paths for flood water downstream of critical locations along the pipeline using GIS. I'm familiar with ...
3
votes
2answers
88 views

Labeling only points that ends with the number 5 in QGIS

I have a shape file with points at evenly spaced intervals, the table has the following fields: Name is up to 32 characters of text. it is currently populated with an eight digit number. Point_No ...
1
vote
0answers
55 views

QGIS Graphical Modeler not finding output files

I am going through the GST 102 Module 5 tutorial which uses the graphical modeler. I keep getting this message when trying to use the output of an Extract by attribute algorithm as a clipper for a ...
1
vote
0answers
32 views

GDAL TMS minidriver in QGIS, problem or bug?

Its great that you can now use TMS layers in qgis! Only, my result is broken. At the 3 highest resolution zoom levels it looks perfect, but at lower resolution layers, i get mixtures of tile shift, ...
1
vote
3answers
75 views

polygons to polygon conversion with attribute name [duplicate]

1) I have a polygon shapefile with 1000 multi-part polygons in it. Each Row of the table is a multipart polygon. 2) I need 1000 shapefiles with 1 multi-part polygon in each. 3) Each output shapefile ...
2
votes
0answers
57 views

Can I export the RGB values from an ArcGIS layer symbology?

I've got a point layer in ArcGIS that has 100 specific color codes based on the name of the store. I'm trying to export the RGB values for these colors (along with the name value it's tied to) so I ...
3
votes
1answer
70 views

How to transform XYZ Raster from WGS84 to UTM ED50 Zone 34

i'm trying to convert an XYZ file from WGS84 (lat/long) to UTM ED50 zone 34. Qgis can load the file as a raster, but i cant see a way of changing the coordinate system or exporting the results as an ...
2
votes
1answer
40 views

Previous shapefiles do not show in re-opened projects

I have previously drawn a lovely shapefile in a project - all saved...good job. I open the very same project and, although the background raster maps project fine, my shapefile will not show. Zooming ...
6
votes
3answers
181 views

Cutting out depth information in raster. Calculating volume in Qgis

I am trying to calculate habitat volume for around 30 fish stocks in Qgis. I have habitat areas (shape files) and Bathymetric information (.tif file). I believe I can calculate the entire volume of ...
1
vote
0answers
37 views

From QGIS to PostGIS [duplicate]

I want to download my data from QGIS to an existing table in Postgresql. I tried to use DB Manager, but the field add to existing table doesn't work. Maybe somebody knows what the problem is? Or is ...
2
votes
1answer
55 views

Why doesn't QGIS automatically find the new plugin update during startup?

I have done a plugin for QGIS and I made a repository (xml) for the end users to install it. Then, I made a new version and update also my repository file with the new one but Qgis doesn't ...
2
votes
1answer
44 views

Can i combine DXF, Google Earth Models, Shape Files and Rasters in QGIS?

I'm an architect, trying to bring a number of data sets together for use in a CAD package (AutoCAD). I have some georeferenced images (.jpg, .jgw.), Some model files downloaded from GoogleEarth (.kml ...
2
votes
1answer
64 views

how to load the QGIS openlayers_plugin in standalone python script (not the QGIS embedded python console)

if I try to load the openlayers plugin in a standalone application it always fails with False, although paths are set, and plugin shows available. (tested on Ubuntu 14.04, QGIS 2.4, python-2.7) ...