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

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3
votes
1answer
106 views

How to get projected centroids in QGIS?

I am trying to get a centroid for several polygons on a global scale, in a way that it would correctly represent the common centre of all the polygons, taking Earth's curvature into account. The ...
0
votes
0answers
145 views

How to install GRASS in QGIS Dufour?

How do I install GRASS to run in QGIS 2.0.1? GRASS is not listed in the Plugin Manager and attempting to access it via the Processing Toolbox gives me the following error:
0
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0answers
65 views

How do I shorten the refresh rate of qgis_mapserv.fcgi?

Is there a way to shorten the refresh rate of qgis_mapserv.fcgi? After having uploaded a revision of a file these changes do not take effect in qgis-web-client. I guess it's because the computed tiles ...
2
votes
1answer
35 views

Get coodinates from point shapefile

I converted a line shapefile to points as you can see in the attached image. Is there a way to know the coordinates of each point? Any help would be really appreciated! PD Im using QGIS 1.8.0
1
vote
0answers
128 views

Merging contour lines along tile boundaries

I am working with the CANVEC data set. The data in canvec is broken up in to mapsheets. eg. 116B04. I have data covering the entire province of the Yukon. I have merged all the data in to one ...
1
vote
1answer
109 views

How does QGIS Topology Checker check the topology of SHP and OSM files? [closed]

Can anybody make me clear if .shp & .osm (OpenStreetMap Data) are holding topological data/relations or not. if .shp files are not holding then how qgis plugin topology checker checks for the ...
0
votes
1answer
124 views

Is it possible to connect to FEMA's WMS and WFS using QGIS?

I have just found out about the wonderful world of WMS and WFS. I have added the FEMA versions of both to QGIS. WMS and WFS. The WMS seems to connect and adds something to QGIS, yet it is not visible. ...
0
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0answers
289 views

How to share ArcMap shapefiles with QGIS?

I'm trying to send a ArcMap 10 shapefile for a QGIS user and something happens with attribute table during the process. Columns will be rearranged, hidden digits will appear to coordinate columns and ...
4
votes
1answer
198 views

Can I create a reusable text annotation style in QGIS?

I want to create a fairly simple map with a few locations emphasized using annotations. I don't like the default annotation formatting: So, I've reformatted the annotation background color, ...
5
votes
2answers
452 views

Ortho Projection produces artifacts

I`m trying to create a sphere-like view using qgis and the "world from space"-projection http://spatialreference.org/ref/sr-org/6980/ (essentialy an ortho-projection). ArcGIS wraps the shapes ...
1
vote
0answers
91 views

Using 3d Polyline in QGIS to calculate Volume?

This question may be completely off the mark. I have a survey drawing in DWG format, I use AutoCAD 2d but the survey was created in LSS. The Countour lines in the DXF have XYZ coordinates. Firstly ...
1
vote
1answer
242 views

How to automate creation of PNG maps using Python?

I have a project with 50 vector layers and I have done custom styling for them. Now I want to make around 30 png files with different xmin, ymin, xmax, ymax. The output size (png) should be width ...
3
votes
1answer
128 views

What are the set of projections that can be accurately georeferenced using polynomial 2?

Background I'm starting with a map from the internet (Encyclopedia Britannica) and georeferencing it using QGIS 2.0.1, I get really accurate georeference solution using polynomial 2 transformation: ...
0
votes
1answer
60 views

QGIS 2.0 Plug In Repository - How to Set Parameters to qgis=1.8

A number of very useful QGIS plug ins available in 1.8 are not available in 2.0. Is there a way to set the parameter page in "Repository Details" to 1.8 so I can access the 1.8 plug ins and check ...
4
votes
1answer
336 views

Python error with open layers plugin QGIS 2

I've been using QGIS for a while but since using QGIS 2 the OpenLayers plugin doesn't work for me on my home pc. (However, I have installed the same version at my workplace with success.) I have ...
2
votes
1answer
59 views

Find GPS midpoint and SD of GPS coordinate along a certain heading in QGIS

I have a set of GPS coordinates (x, y) along with heading information. The heading for these coordinates is more or less the same and the coordinates are within a few meters of each other. How can I ...
2
votes
1answer
198 views

Which data providers support loading attribute tables without geometry?

I have a table in Memory from a cx_Oracle query (a list of rows, and a list of field names and their types) in my python plugin and I want to load it as a geometry-less layer (Attribute table) in ...
2
votes
1answer
578 views

How do I run the nvis tool in QGIS GRASS?

I am trying to follow this workflow: [How to generate a DEM from a countour Shapefile?] and it's running fine, and when I hit view output or view results I end up with a flat raster with shading ...
1
vote
0answers
41 views

problem on loading kriging outputs [duplicate]

My problem is the following: everytime i run ordinary kriging or other interpolation techniques i obtain this error message from QGIS Notice that these are the details for SAGA I would like a ...
3
votes
1answer
325 views

How to create DEM from contours without ArcGIS Spatial Analyst licence?

I'm trying to create a 3d DEM/DTM from a flat contour shapefile which has height data attached to each contour, but I'm not sure how to do this? I've found this post, on creating a dem from contours ...
2
votes
0answers
145 views

Can QGIS display projected coordinate system for map, at same time as lat/long graticule and scalebar in km? [closed]

I am aware of this question, which was posted a year ago, but its accepted answer appears to be a workaround rather than a solution to the issue which is the subject of this Question. I wish to ...
0
votes
1answer
61 views

Export data of points and polygons which are intersected

I have a shp file of roughly 100 Polygon. I also have a corresponding list (including X,Y data) of about 3000 points, in a csv file. Overlayed within QGis the 100 polygons contain about 90% of the ...
0
votes
1answer
113 views

Is it possible to calculate a value based on values of another row?

I have a point shape file in qgis. For one of the attributes, I would like to offset the values, i.e. the value for point 1 goes to point 10, the value for point 2 goes to point 11 and so on. I see ...
0
votes
1answer
159 views

No module named pyspatialite- plugin:Qspatialite, OpenSUSE 13.1

I cannot run the plugin because of module missing. I can't find that module in the OpenSuse repository, and python community repository. I'm using QGIS 2,0 and OpenSuse 13,1 Where can I find ...
1
vote
1answer
193 views

How can I add height data to a polyline in QGIS?

I want to place a polyline at the correct altitude in QGIS. Is that possible and how do I do this? What I have is a polyline (railroad) and I want to add information on the electrics above the ...
7
votes
2answers
528 views

How do I use the Natural Earth SQLite DB with QGIS?

I just downloaded the Natural Earth data in SQLite format from http://www.naturalearthdata.com/downloads/. I had assumed that this would be a SpatiaLite database, but it appears not to be! QGIS is ...
1
vote
0answers
34 views

how to tidy up line intersections

I am very new to QGIS so please bear with me. I am using version 2.0. I am trying to tidy up lines that I have collected using a vertex function on my gps. When I zoom in to the map in QGIS it shows ...
1
vote
2answers
364 views

How to select a multiple field value by expression from the same layer in QGIS?

Using QGIS in the operation 'select by expression' how is the correct expression to select multiple field value? ex. City NAME = ROME and NAPLES (expression is invalid)
1
vote
0answers
70 views

Clustering a number of points with the same coordinate around a central point

Is there a plugin in QGIS to randomly distribute points with the same coordinates around the coordinate? Similar to the "shift point plugin", but instead of producing a circle of points the points are ...
1
vote
1answer
80 views

Question about quantum gis, and importing csv point data

I'm trying to add some point data from a csv file (it's in decimal degree lat lon) and overlay over road data that I already have added. The problem is that I can't get it to line up. I'm sure I'm ...
0
votes
0answers
142 views

QGIS 2.0 Plug Repository Connection Failed

I'm trying to connect to the QGIS Official Plugin Repository but the status within the Plugin Manager window is always"unavailable" for the URL - http://plugins.qgis.org/plugins/plugins.xml. I'm ...
4
votes
0answers
98 views

How can I create a form so the user has to be authenticated to access a project?

I have a login form in QGIS and when it is loaded, python gives me an error for, apparently, not recognizing the findchild part. This is due to the fact that the form isn't loaded before the script is ...
1
vote
2answers
76 views

Missing lxml in QGIS 2

I made a QGIS plugin in QGIS 1.8 doing a lot of XSLT transformation and other XML handling with the library lxml. After upgrading to QGIS 2.0 this plugin does not work anymore: "ImportError: No ...
1
vote
1answer
315 views

3D Polygon Layer Stack with QGIS

I was curious if there is a way, or plugin to visualize a 3D polygon layer stack in QGIS (or another open source package). I have looked at NViz, but it only seems to work for rasters. I have a ...
0
votes
0answers
143 views

QGIS 2.0.1-3 not opening

I've excitedly just downloaded the latest version of QGIS 2.0.1-3 (QGIS Dufour) and now it won't open. I performed the exact same process last night (without problem) on my home laptop (64-bit OS ...
1
vote
1answer
51 views

How to get estimates of areas of overlapping polygons in one shp to another?

Sorry for my ineptitude, but I have two vector shape files of Africa. One has polygons of countries, and one has polygons of tribes a long time ago. What I want to do is to find the intersection of ...
0
votes
0answers
156 views

Unable to render layers in MapCanvas using PyQGIS/PyQt4

I am trying to get some layers into a MapCanvas and style them. I am following the PyQgis Cookbook info here but my code is just not working. I've been spinning my wheels on this for over a week now ...
2
votes
1answer
77 views

How to select vector features with partial (>33%) overlap with another vector feature?

I have a grid and a range map, and would like to select those grid squares which overlap at least 33% with the range map. The range map is a single vector feature. (I'm new to QGIS but have some Arc ...
4
votes
0answers
131 views

Convert Graphics to Vector in QGIS

I am wondering if there is a way to convert a graphic produced from symbology in QGIS to a vector layer (ie: shapefile). I have a point layer with bearing direction in the attribute table. Following ...
0
votes
1answer
322 views

Unable to load PostGIS vector layer into QGIS using python cookbook recipe

I'm having trouble loading a PostGIS layer using Dufour (from osgeo4w), using the guide at http://www.qgis.org/en/docs/pyqgis_developer_cookbook/loadlayer.html. I just get the 'invalid layer' message. ...
2
votes
1answer
94 views

Is there no editmode for CSV files? [duplicate]

I load a delimited text layer and it get's visuialized. Unfortunatly I don't know why I can't switch to edit mode. I already worked with similar .CSV files in edit mode before, under the same setup :( ...
1
vote
2answers
45 views

Linking data to road colour scheme

I'm getting started with a qgis map showing the quality of roads in my town. I have various data which create an index of 1-5. How do I link this index data to road data in a map, showing the bad ...
1
vote
0answers
84 views

How can I change the NoData value in QGIS 2.x using the python console

I'm trying to add a NoData value to a single band raster image in QGIS 2.0 using the python console but can't find the right bit of code to do it. Here's what I see on the console: >>> ...
2
votes
1answer
389 views

How to label vector features programmatically?

I am using python for QGIS 2.0.1 and I have a vector layer of points representing the positions of state labels. I want to display the 'state abbreviation' attribute on the corresponding point for ...
2
votes
1answer
179 views

How to use SAGA ShapesToGrid via Processing in a Python plugin?

I run these lines in my code: vectorlayer_vector = ftools_utils.getVectorLayerByName(inputLayer) Elevation = self.lineAttrib.currentText() cellSize = int(self.linePix.value()) outPath = ...
0
votes
2answers
93 views

Problem loading view from postgres

My problem is loading view table from Postgres. Here is my view table: SELECT h1.gid, h1.st_buffer FROM vmo_buffer_2m h1 LEFT JOIN vodomjeri h2 ON st_intersects(h1.st_buffer, h2.geom) WHERE ...
3
votes
1answer
244 views

How to define a line's width graduated by its attributes?

I have a line shapefile with lots of lines that have different attribute values. I want to present these lines in different widths according to their attribute values without classes but a graduated ...
1
vote
0answers
130 views

Accessing existing instance of qgis from stand-alone python script

For my own data analysis pipeline, I am running a split screen setup with iPython notebooks on one side, generating variables from source data, pushing them to a csv file which qgis then reads/joins ...
4
votes
1answer
125 views

Data defined label alignment option greyed out on new Quantum GIS Dufour

I am trying to customise the positioning of labels in relation to points in a vector file layer in the new QGIS 2.0. In QGIS 1.8 I was able to enter two customised X/Y columns in the attribute ...
0
votes
1answer
73 views

Interpolation without a point layer in QGIS

I have a vector layer with incidence data (i.e. frequencies) and I made a graded color map from this using the above frequencies. Now I am looking forward to creating an interpolated (kriging) map ...