Tagged Questions

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

learn more… | top users | synonyms (1)

0
votes
2answers
185 views

Is it possible to intall the opengeostack and QGIS nightly?

Did someone managed to get the opengeostack running alongside qgis so the plugin suite-qgis-plugin can be used? I am trying it on ubuntu1304, installing opengeostack works ok, but then when installing ...
1
vote
2answers
109 views

Coordinates system in degrees in plugins for QGIS

After adding a vector layer of coordinates of settlements of a part of the world INTO QGIS 1.8, I wish to add a topographic or other nice looking, colored map. Trying plugins like maps from Google ...
1
vote
1answer
74 views

Problem opening Natural earth quick start for QGIS

Trying to open the file "Natural_Earth_quick_start_for_QGIS.qgs" a window opens, listing 20 "bad layers". The window is entitled "Handle bad layers". Consequently I cannot even get started with ...
7
votes
4answers
270 views

How to compare areas in scanned historical land use maps

I am a relative beginner to using GIS, and am running QGIS 2.0.1 in Linux. I have two historical maps which I want to analyze, that show land use patterns in the same area at two different moments in ...
7
votes
0answers
789 views

GRASS v.Overlay/QGIS Intersect Speed intersecting line and polygon

Im currently trying to convert my scripts from ArcGIS to QGIS but one aspect that is extremely slow (imo) is trying to intersect a polygon with a line feature. I feel as though there must be a better ...
4
votes
2answers
2k views

Dissolve polygons in QGIS (GEOS) with tolerance

I have a polygon vector layer representing the area inundated in a flood. The layer has been produced in a such a way that some of the areas are composed of multiple smaller touching polygons (see ...
1
vote
1answer
219 views

Save as Image geotiff from OpenLayers plugin [closed]

Now i'm working with the new version of Qgis 2.0 but I have a problem with the OpenLayers plugin. I take a geotiff screenshot of an area in EPSG:3857 and then I load the image.I'd check out the CRS of ...
0
votes
1answer
270 views

Shapfile created in QGIS does not fit in ecognition project

I have various shapefiles - some created by others, some created by my self. They should all have the same size of the underlying Raster file. The shapefiles have been created on top of a Raster file ...
1
vote
2answers
163 views

how to set width & height of a polygon in QGIS

I can't setting width and height of a polygon How to do that in QGIS? Thank you
2
votes
1answer
203 views

How to find out whether a photo is geotagged or not?

I use a android app called OSMTracker. This app records the GPS track and can take pictures and notes. Using JOSM software, the photos are shown exactly at their coordinates (location) but i cannot ...
2
votes
1answer
1k views

Implementing geometry_columns table in SQL Server for QGIS

We are using QGIS 1.8 and Sqlserver 2008.Following http://hub.qgis.org/issues/8525 solution we have created table geometry_columns. since we already have lots of table how do I fill this table ...
0
votes
1answer
103 views

Custom python scripts do not appear in SEXTANTE QGIS

Custom python scripts do not appear in Scripts menu in SEXTANTE plugin unless they are either empty or are as simple (and useless) as: ##foo=group ##input=raster OS is openSUSE 12.3; QGIS 1.8 and ...
2
votes
0answers
60 views

Error importing NOAA’s National Geophysical Data Center as delimited text layer in QGIS version 1.02

I've been struggling with trying to import the most recent data from NOAA’s National Geophysical Data Center earthquake information into Quantum GIS 1.02 for weeks now for a class assignment. I'm ...
0
votes
1answer
959 views

Can not make qgis.db private copy

I've just installed Qgis 2.0.1 and the above error message appears. Does anyone know how to resolve this problem? I think I need to change the permissions of the relevant folder, but I'm not ...
3
votes
2answers
200 views

Can QGIS display individual WMS tiles as it fetches them?

I have a QGIS project accessing a base WMS layer with imagery. How can I tell QGIS to display the individual tiles as it fetches them so that I won't wait for the whole image to load until I see ...
1
vote
0answers
96 views

Getting an error when I try to import a loaded vector file to the QGIS GRASS Plugin

I am getting an error code when I try to import a contour line vector file GRASS via QGIS. I have been trying to create a DEM from the contour lines following this tutorial: ...
0
votes
0answers
154 views

How can I embed IPython into the QGIS console?

I would like to use Ipython in the console to perform tasks more easily. How can I do that? Thanks a lot!
1
vote
4answers
270 views

How to unpolygonize and remove outermost border?

QGIS has "polygon to line" but this isn't exact reverse engineering of "line to polygon". I want no overlapped border closed lines, just segmented (on each intersected point) lines. Additionally I ...
5
votes
2answers
186 views

Time Manage + Twitter in 2013

I am a geography teacher and would love to map tweets in QGIS for my pupils. I followed all the instructions but it seems Twitter have changed the way they stream their tweets. I can cope with the GIS ...
1
vote
1answer
227 views

Restricting Tin interpolation in QGIS

I am trying to do a bathymetric map for a lake using QGIS. However, I see no option to impose a mask so interpolation does not extending beyond the boundaries of my lake. I have traced around the ...
0
votes
0answers
59 views

Can the software be installed silently?

Can QGIS be silently installed and uninstalled? We are looking to deploy this to several users for evaluation.
2
votes
0answers
361 views

How to specify cost attributes for network analysis in QGIS using the GRASS plugin?

I have a road dataset with information about the length, speed and drivetime for each segment. I use QGIS 1.9 with the GRASS plugin to do different types of network analysis, but how do I set up the ...
1
vote
3answers
439 views

Join excel attributes to shape attribute

I am wondering if there is a way to join the attributes from excel tables to shapes in Qgis. I have abbreviations in the shape and want to add the associated complete names from excel file by ...
1
vote
1answer
84 views

Snap mean coordinate to layer in QGIS and creating MCs for multiple shapefiles

1: I wish to create a mean coordinate for a group of points. However, I would like the new point to be snapped to the nearest point from the set of points used to generate it. How might one go about ...
2
votes
1answer
1k views

PyQgis question: How to change or set active layer?

Developing a qgis plugin, I found that if no layer is selected in the Layers panel I can iterate over all layers and do anything to them, but "activate" them. Could someone give me a hint please? ...
0
votes
1answer
127 views

Why does the “Dissolve” tool in QGIS create an empty layer?

I have a shapefile containing cadastral data. I would like to dissolve the polygons using my field "OwnerName". My goal is to get one polygon per landlord's name. When I use the "Dissolve" tool, QGIS ...
4
votes
1answer
384 views

Can Spatialite SQL statements be issued with a python script in QGIS?

In my previous scripting environments (ms-access and Manifold GIS), it was possible to create and execute SQL queries from withing VBA or VB Script procedures. This is really useful for things such ...
1
vote
1answer
112 views

how can i install Semi-Automatic Classification plugin manually?

I try to install with Fetch Python Plugins. But fetch python plugins show only those which are installed? can i install manually when direct installation failed repeatedly?
4
votes
2answers
891 views

How to merge TopoJSON features?

I currently have a coordinate based map of the US and it's states for topojson (https://github.com/mbostock/topojson). The coordinates are a JSON array (as topojson works), data looks like this: ...
2
votes
0answers
89 views

Convert pixel value histogram to table

I am working in QGIS 2.1 with the National Land Cover Database 2006 land cover layer. It is a raster layer with pixel values corresponding to different land cover types. I have clipped this raster to ...
1
vote
1answer
115 views

Can't get the openlayer plugin to operate [closed]

I can't get the openlayer plugin to run. I've got QGIS V1.8 on Windows 7. I've tried various repo's recommended on different sites; http://plugins.qgis.org/plugins/plugins.xml & ...
3
votes
2answers
186 views

How to determine the location that has the most intersections with other polygons in a certain distance/buffer?

I have a very scattered map with a lot of very differently shaped polygons. Now I want to determine the location where a circle polygon of a certain size intersects the most surface of these scattered ...
2
votes
1answer
68 views

Why does Fetch Python Plugins responded with only the installed ones?

I use QGIS 1.8. Whenever I demand to install plugins through Fetch Python Plugins it displays only those the already installed. I couldn't find for example; point sampling, group stats and photo2shape ...
0
votes
2answers
215 views

Intersection between points and polygons in QGis

I have the following problem. I have a shapefile of points and a shapefile of polygons. I want to know WHAT points (not how many) fall inside EACH of the polygons of my multipolygon shp. I thought ...
0
votes
2answers
427 views

Deleting points that fall outside a polygon

I have a polygon that is my region of interest. I also have a database of observation points that I have imported into QGIS as a points layer. I'd like to exclude all the observation points that ...
1
vote
1answer
292 views

What's the correct transformation for Lambert Conformal Conic for Mexico?

I have a shp archive without the .prj file. I don´t know the proyection of this shp, but I think it is in lambert conformal conic. Can anybody helpme to proyect this shp? i´ve tried to proyect it in ...
1
vote
1answer
231 views

How to install two versions of Qgis on Ubuntu 12.04?

I would like to run multiple versions of QGIS on Ubuntu 12.04. Can I do that, and how if so?
4
votes
2answers
302 views

Best practice in writing automated tests for QGIS plugins

I'm looking for some best practice advice on writing automatic tests for QGIS plugins written in Python. I have written tests for Python scripts in the past using PyUnit (the unittest module), but ...
0
votes
1answer
130 views

qgis — style edges of layer shapefiles to have thicker borders

I have two layers I'm working with here, both of North Carolina. One is "townships" the other is "counties". I want the counties shapes to have thick edges with no fill-in color. I couldn't find ...
2
votes
2answers
309 views

Can QGIS use a non-spatial Oracle Database?

I'm building my first plugin in qgis, that needs to read some coordinates from an oracle database (not oracle spatial database) and create a shapefile with this points. I'm searching but only find to ...
2
votes
2answers
220 views

How to save colour (color) ramps in QGIS

This strikes me that it should be simple, but efforts in QGIS and research here and elsewhere are not providing a solution. I have a (vector) map which I have to mark out in colours according to the ...
0
votes
2answers
296 views

How to find and replace all null values in multiple columns?

To find and replace all null values in a specific column I am using: case when "myColumn" is NULL then '99999999' else "myColumn" end But how can I use the QGIS calculator to find and replace all ...
4
votes
0answers
258 views

How do I install Orfeo toolbox and Qgis 1.9?

I'm having a lot of trouble getting Orfeo toolbox and Qgis 2.0 working. I followed the qgis wiki instructios, added the ppa, installed qgis 1.9 (it's beautiful, great work!). But when i tried to ...
2
votes
1answer
193 views

QGIS Georeferencer, unexpected transformation, and GCP placement

Im trying to get the sample map which i believe to be EPSG:3112 into QGIS and geo referenced. In my screenshot, on the right is the raster in georeferencer with the points i have added. On the left is ...
1
vote
1answer
126 views

Can SQLite and SpatialLite files be linked

Coming from a ms-access background, it is common to split up larger applications into several database files. An ms-access database can then access data that is in another database via a linked ...
0
votes
2answers
95 views

How can I delete dangling paths after merging features

In my previous question I've asked how to can I merge different polygons while converting to GeoJSON and TopoJSON. After a day of researching I've realized that, rather trying to do it command line, ...
1
vote
2answers
171 views

Integrate grid and polygon of municipalities keeping the biggest municipality per cell with QGIS (or another)

I have a 9x9 grid and a polygon of municipalities of an extensive area of Brazil. My goal is to have a field indicating the biggest municipality per grid cell. I've been trying with intercept without ...
1
vote
0answers
147 views

Personal Geodatabase not recognized as valid datasource in the last QGIS Windows Weekly build (64 bits)

I was using Personal Geodatabases in QGIS without any problem but it's stopped to work since I installed the last 64 bits weekly build for Windows (1.9.0-35-Setup-x86_64). I'm now receiving an ...
4
votes
2answers
570 views

Reduce the resolution of a shapefile in R (or QGIS if necessary)

I'm using shapefiles of history U.S. state boundaries from NHGIS to make maps in R. These shapefiles are much higher resolution than I need when making maps at the scale of the country: over 2 million ...
0
votes
1answer
115 views

Calculate attribute height of point data

I have an x (easting), y (northing) and z (height) values associated with my point shapefile. I would like to calculate the z values from the DTM I have - how do I do this in QGIS? I am fairly new ...