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

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5
votes
2answers
6k views

How do you Turn on the GRASS plugin in Quantum GIS?

I downloaded and installed Quantum GIS 1.5.0 with GRASS using the OSGeo4W installer on my Windows XP machine. Unfortunately, when I go to Plugins>Manage Plugins I cannot find the GRASS plugin. When ...
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 ...
4
votes
2answers
88 views

Why does the qgis LTR release date lag behind the current release?

This is just a simple curiosity but I haven't been able to find an answer. Qgis 2.14 will be the LTR, but when it was released it was posted as the current release with 2.8.7 still as the LTR. Will ...
4
votes
3answers
73 views

How to set different page orientation per page in QGIS Print Composer?

I wanted to have portrait for page 1 and landscape for page 2. How could I achieve that in QGIS Print Composer?
4
votes
1answer
67 views

How to display different SVG icon in the same layer in QGIS

I am working with a ponctual layer in QGIS 2.12.3 (Lyon). I have a determine a few points in my layer. Each point represents a different activity (ex : climbing, hiking, etc). In order to have a ...
4
votes
3answers
67 views

Unexpected behaviour using ST_Equals() with QGIS

Let's say there is a table 'polygon_a' and a table 'polygon_b'. Each table contains three polygon features. The polygon features are spatially equal. CREATE TABLE polygon_a ( gid serial NOT NULL, ...
4
votes
2answers
83 views

How to import a Composer Template into QGIS Print Composer?

How can I import a .qpt file into Print Composer (Composer Manager) in QGIS. I've tried saving it in the composer_templates folder but to no avail.
4
votes
0answers
61 views

OS terrain 50: .vrt from zip files

I tried to follow what was suggested in How to use OS Terrain 50 in QGIS, but I got the following problem: in spite of being generally able to generate .vrt files using gdalbuildvrt from unzipped ...
4
votes
2answers
156 views

Clip polygon using buffer

I'm very new to QGIS, so apologies if this is a daft question. I've been trying to resolve my problem for a couple of days and I can't get anywhere. I have searched for similar issues here on SE but ...
4
votes
2answers
98 views

Easier calculation of a surface using QGIS

I'm looking for an easier way to calculate the surface on QGIS: My project CRS is in Lambert93. Currently, when I'm calculating a surface using QGIS, when the surface seems wrong, I always have to: ...
4
votes
1answer
75 views

Geoprocessing tools fail though CRS same, prj-file ok, edit mode off, topology valid, etc

For my layers none of the QGIS geoproccesing tools (difference, intersection, etc. all give empty attribute tables) work, though I've checked for all (?) error sources (as in the title). Then I tried ...
4
votes
1answer
106 views

Use “facet_wrap” in ggplot2 with QGIS?

I'm using QGIS 2.6.1 and R version 3.2.2. I'm struggling to get the syntax on a R Script for creating plots via QGIS processing to work. My understanding is that R syntax in QGIS Processing is ...
4
votes
1answer
284 views

qgis 2.10.1. mac - geotiff singleband pseudocolor [duplicate]

i've installed mac version from kyngchaos including all required packages ... ... and just noticed the following: while windows version behaves like expected when trying to render an ordinary tif via ...
4
votes
2answers
328 views

Calculating unique ID value for a field in QGIS using python

I am trying to calculate a unique ID field for a vector layer in qgis, using python. I found some code to calculate attribute values, and tried to increment the value in the expression, but it doesn't ...
4
votes
2answers
133 views

Is it possible to copy a graduated scale from a polygon to a point layer in QGIS?

I have a polygon layer (represented by cells) and a point layer. I've used the graduated symbology with the polygon layer. Now I'd like to export this graduated scale to the point layer. The field of ...
4
votes
6answers
1k views

How do I make a SHP file from waypoints?

I have a Garmin etrex 20 and I want to convert my waypoints into a shapefile for QGIS. The waypoints need their name and background information with them in the shapefile.
4
votes
1answer
186 views

How to rotate labels by the same angle as the map in the composer?

Does someone know if it is possible to make the labels rotate the same angle as the map in the composer? I'm trying using the expression attribute( $map, rotation) in the data defining placement, but ...
4
votes
1answer
443 views

getting a plugin path using Python in QGIS

How to get a plugin path using Python? I tried QgsApplication.pluginPath() I got u'/Applications/QGIS.app/Contents/MacOS/../PlugIns/qgis' But I actually store the plugin in ...
4
votes
1answer
577 views

QGIS Standalone C++ Application with Qt: “The program has unexpectedly finished”

I'm trying to develop an Standalone Application with Qt and QGIS API. There are several code examples that should work, but they don't. The Problem is that everytime I use "QgsApplication" the ...
4
votes
3answers
172 views

QGIS Composer thematic map : one (png, pdf, etc.) map per feature type

I've got a shapefile that contains thousands of features that can be group by categories. These features are sometime located in the same place so they overlap. An example of the content of my ...
4
votes
1answer
304 views

Making QGIS buttons and my Plugin button mutually exclusive

I've added a toolbar to the QGIS main window and I've added some checkable buttons to the toolbar. How can I make my checkable buttons untoggle QGIS default toolbars' checkable buttons? That is, ...
4
votes
2answers
1k views

Setting layer visibility in QGIS Python API

Im having a problem toggling the visibility of map layers in pyqgis (2.4). I have a simple interface, just the map canvas, no legend, and basically a radio button that toggles between two raster ...
4
votes
1answer
311 views

How to get User and Password of a PostGIS layer from PyQGIS

I wonder if it is possible to get the user and password for a PostGIS database if they are stored in the PostGis connection information. I get the connection information at the moment from the ...
4
votes
1answer
149 views

In which way is height information stored in a DEM?

I'm struggling with different DEM data, because I don't know how to convert the height information in meters. When I load ASTER and SRTM tifs in QGIS, it shows me the spectrum of the grayband (0 to ...
4
votes
1answer
517 views

How to do loops on raster cells with python console in QGIS?

I'm new here and beginner with python. I'm looking for a solution to my problem for some hours but now you are my last chance... I'm using the python (2.7.5) console in QGIS (2.4.0). Is there a ...
4
votes
1answer
1k views

Is there a way to run a python script on opening a QGIS project?

I have a .csv file containing financial data which is generated on a regular basis outside QGIS. Then I want to create a PyQGIS script that will add the .csv file as a layer in my project. (The idea ...
4
votes
2answers
2k views

Proportional Symbol Formatting

I need to create a proportional symbol map for a GIS class. I am wondering, how can I manually change the symbology to make the dots grow in size depending on their magnitude represented, and also how ...
4
votes
2answers
271 views

How to tell QGIS where to start marker line interval?

I want to tell QGIS where to start with a marker, like: use 3 markers, start at positions 0, 2, 4, and apply an interval of 12 to each marker. However, after searching for hours, I haven't found a ...
4
votes
1answer
1k views

How to remove all selection from all registered layers using QGIS plugin?

I want to remove all selection from registered layer in QGIS using Python. I tried to clear the map canvas using: self.iface.mapCanvas().clear() self.iface.mapCanvas().refresh() but the ...
4
votes
2answers
3k views

how to use rectangles ovals digitizing in qgis

i added the new vector layer in QGIS and I want to draw a cicle of 500M or 1000M from center. I also added the pluginn Rectangles ovals digitizing in QGIS. But the options of this pluginn is not ...
4
votes
2answers
712 views

Need Projection Help to Buffer Lines in QGIS

I need to create buffers (1km, 3km, and 5km) around the rivers of this shapefile from NOAA, something I remember being relatively simple in my GIS class. However no matter what I do the buffers I ...
4
votes
1answer
433 views

Historical U.S.G.S. Georeferencing

I have downloaded a historical USGS map that is suppose to be a geoPDF. My understanding is that QGIS cannot directly read geoPDF's. I have not had any luck in converting it to a geoTIF in order to ...
4
votes
2answers
4k views

QGIS, Table Manager cannot rename column title

My current attribute table has a column whose title exceeds the ten letters maximum. I installed Table Manager, hoping I could rename the certain field to further use it (in order to add some ...
4
votes
2answers
1k views

How to average values in a point layer with respect to polygon layer in QGIS?

I am new to GIS and have the following problem: I have 2 layers: a point layer with a column that contains numbers (pollution index from specific measurement point) and a polygon layer with different ...
4
votes
1answer
402 views

Can county level info be brought into a map?

I have a csv file of Clovis projectile points that were recorded only with the county in which they were found, no coordinates at all, no shapefiles. Is there a way to bring these into a state map ...
4
votes
1answer
598 views

How to measure the distance of multiple points to a line

I have two shapfile in QGIS to which I am trying to find the distances between. I have a shoreline which is a vector line and then I have hundreds of data points in the ocean. What I am trying to find ...
4
votes
1answer
338 views

How to connect waypoint pairs and calculate length?

I want to make a path out of points and calculate the distances of each single line. I have a point layer with waypoints of a research vessel. The way points have in the attribute table a date and a ...
4
votes
2answers
614 views

Can't select layer to upload to GPS

I'm trying to upload a vector layer to my Garmin GPS unit. I've saved it as GPX (WGS 84); opened the GPS Tools dialogue in QGIS 1.8; selected the "Upload to GPS" tab; and clicked on the "Data layer" ...
4
votes
1answer
2k views

Can the units of the measure tool in QGIS be changed?

All, I'm trying to do some error-checking with some rasters I'm creating, and want to measure line distances on the map in feet, rather than meters - which is what the measure line tool seems to be ...
4
votes
3answers
3k views

How to install QGIS 1.8 plugin Georeferencer?

My question is about qgis 1.8 georeferencer plugin. I installed the new version qgis 1.8 but I don't have the georeferencer plugins, how do I install it? I used the georeferencing plugin with QGIS 1.6 ...
4
votes
4answers
2k views

What are the advantages either way between GML and Shapefiles?

After a good start many months ago of getting into GIS through QGIS, I had to drop what I was doing and did not touch it for quite some time. I am now able to get back into it and have a need to load ...
4
votes
1answer
948 views

Join attributes by location

I am trying to join multiple records that occupy the same location (polygon centroid) and have tried using the join by location plug-in but have found this does not work for me in this case as I have ...
4
votes
1answer
159 views

Points warped when exporting to shape

I have recently purchased a Trimble GeoXH (used) and have done a few surveys. I have done differential correction in Trimble Pathfinder Office and all points seem fine. When exporting to shape and ...
4
votes
3answers
2k views

Summing attributes intersected by under a radius

Apologies - new user. I am working with QGIS on Mac OS X and with shapefiles downloaded from the US Census Bureau that show population data by state and by county. How do I: select certain points ...
4
votes
3answers
5k views

Editing polylines in QGIS (extend, trim, fillet etc)

I was wondering, if its possible to edit lines and polylines in qgis, in similiar way as autocad commands "extend", "trim" and "fillet"? About how the commands for in Autocad, very shortly: The ...
4
votes
1answer
2k views

Unit of $length in QGis Field Calculator

I'm calculating field of various features in my shapefile using QGis. I'm getting some sample length as 0.134914579766986. I want to know in what unit (eg: meters, km etc) is the above value ?
4
votes
1answer
1k views

Why don't my polygons from MSSQL2008 display in QGIS?

I have imported a polygon shape file in MSSQL2008 using Shape2SQL loader without any issue. When I import the loaded polygon file in QGIS, I can't see it ! When I import other point or line features ...
4
votes
1answer
2k views

Is there a silent installation command without the desktop shortcuts? [closed]

I installed QGIS with Microsoft SCCM 2012 and I want to make a silent install without desktop shortcuts. I managed to do a silent install with / S but I found no s command to delete desktop ...
4
votes
4answers
1k views

TIN interpolation crash in Qgis

I have problems using the function TIN(linear) interpolation in Qgis. The program crashes when larger areas is interpolated. Map properties: vector map, Geometry typ = Point, features in this ...
4
votes
1answer
741 views

Why are the polygons in my GML not rendered?

I tried to view GML files from download services ( http://services.cuzk.cz/gml/inspire/cp/epsg-5514/ ) and I have a problem with viewing of polygons from layer "CP:CadastralParcel". This Layer ...