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

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3
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1answer
348 views

How can i merge lines with same name and intersect each other?

I have shp file with 50k lines (roads). Many roads have same name like 'high road' . some of them are the same road (they intersect each other) and some are located in different places of the city. I ...
3
votes
1answer
170 views

Why can't I edit polygons once they have been saved to MySQL?

I have a simple table with an id field and a polygon field in mySql. Using QGIS I can add new polygons and give them an id. Before saving them I can also edit them. But once a polygon has been saved ...
3
votes
0answers
125 views

Why doesn't Polygonizer copy the line ids to my polygonized shapefile?

I am trying to convert a line shapefile into a polygon shapefile using Polygonizer plugin, and when my new polygons are created all the cells in my id field are "Null", although I have clicked "copy ...
3
votes
1answer
2k views

Import GPX file to QGIS and correct apparent CRS problems

I am using Easy Trails software on an iPhone to output a gpx file of a walk. When I import the file (import vector layer) to QGIS, into a project with OSGB information and the correct CRS for OSGB ...
3
votes
1answer
139 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 ...
3
votes
1answer
586 views

Why are the features in my memory layer not displayed?

I am trying to create a memory layer, I followed the directions from the page below but no points appeared on my map. First I tried typing each line into the python console and I also create a plugin ...
3
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0answers
101 views

How to digitize 90 degree angles? [duplicate]

Possible Duplicate: How to create polygons with straight lines and right angles in QGIS? In QGIS 1.8 is there a way to digitize buildings etc. with perfect 90-degree angles, Or, edit a ...
3
votes
1answer
2k views

How to export shp to kml?

I already browsed your FAQs, and could not come up with a good answer, I am trying to export shp files to kml to be placed on Google Earth. On a previous version of QGIS it was as simple as right ...
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0answers
238 views

How to debug Quantum GIS PlugIn Visual Studio DLL?

I develop a Quantum GIS plugin layer using Microsoft Visual studio and placed it in my plugins folder of my customized quantum gis application. I now intend to debug the DLL using Microsoft Studio. ...
3
votes
3answers
8k views

Editing a KML file or converting KML to Editable format with attributes

I'm using QGIS. I'm trying to either edit a .kml file someone else created in Google Earth or convert it to another editable format (like a .shp file). I've read the following threads without really ...
3
votes
1answer
2k views

Is it possible to increase/reduce features proportionally?

Is it possible with QGIS to increase or reduce features (polygons or lines already drawn) proportionally? Preventing me to redraw several times new polygons :) See picture above: Making it possible ...
3
votes
1answer
620 views

QGIS custom CRS for map of manufacturing shop floor

I'm working on a web app that shows a map of a manufacturing plant's shop floor. I've built it in Inkscape and QGIS, but when I try to load it into Tilemill, I get a CRS error. Specifically, it ...
3
votes
2answers
720 views

How to densify a polyline according to a specific length? [duplicate]

Possible Duplicate: Add vertices to lines I am using QGis 1.8.0 I would like to densify a polilyne according to a particular length of segment (ex. 200 m). I know it is possible with other ...
3
votes
1answer
1k views

Using Qgis server with Ubuntu 12.04

I realise there had been many posts on this subject but unfortunately I need to post again. I've been banging my head against this all day. I'm trying to get qgis server working with Ubuntu 12.04 ...
3
votes
2answers
832 views

How to join lines in QGIS for later using “lines to poly”?

After successfully merging lines (using snapping) with merge_selected_features i got nice result - one merged line. Next thing was to make polygon from created merged line. Result is not nice - it ...
3
votes
1answer
2k views

pyqgis: How to get features of selected geometries

I wonder if anybody could provide an example how to get the attributes of selected Features? I tried the folowing Code in the python Console - but I'm stuck at the point where I'd like to get the ...
3
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1answer
792 views

Python 3 support in QGIS?

As python3 is getting standard more and more I wonder wether there is or will be support for python 3 in QGIS?
3
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1answer
1k views

Why can't I download the georeferencing plugin for QGIS 1.7.4?

I used the georeferencing plugin with QGIS 1.6 and now that I've upgraded to 1.7.4 I'd like to do it again. But when I search for the georeferencer plugin, it's not available! Am I doing something ...
3
votes
2answers
1k views

Normalize raster values to 0-255

I need to normalize the values attained from a band ratio to 0-255. I'm using QGIS. How do I do this? Any ideas?
3
votes
3answers
296 views

How to visualize the vertices of a graph in QGIS?

I tried to visualize the graph generated by osm2po and rendered that graph in qgis. Now what I am trying to do is plot the vertices in the graph. So that I can visually see where the nodes/vertices ...
3
votes
1answer
210 views

Create new polygon layer based on areas of varying numbers of stacked polygons

I have several species range maps (as polygons) that overlap/stack. From this, I am trying to identify areas of highest biodiversity. Ideally, I'd like to create a new polygon layer, where 1 part is ...
3
votes
1answer
3k views

How do I clip/mask a satellite photo to a polygon?

Given a shapefile composed of contiguous polygons, I'd like to clip (or mask) regions of satellite photo to the polygon outlines, and export each resulting raster in medium resolution for further ...
3
votes
1answer
211 views

Is it possible to change the year range of time manager in QGIS?

I have a shapefile with a start and end time field, properly formatted. However my dates range from 1864-1995. When I try to use the shape file with the QGIS time manager plugin I keep getting this ...
3
votes
1answer
4k views

How to filter features in a layer?

I am trying to display certain features in a shapefile-based layer using QGIS. I have found the subset function in the properties panel, which does exactly what i want, but is too tedious given that I ...
3
votes
1answer
851 views

Splitting lines at a specified distance

Does exist some plugin with it is possible to Splitting lines at a specified distance in Qgis?
3
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0answers
3k views

How to load and view .gri and .grd files in QGIS [closed]

An online GIS Repository called DIVA-GIS (http://www.diva-gis.org/gdata) offers data in three formats - ERSI files, "DIVA gridfiles", and DBF files The DIVA gridfiles have extensions .gri and .grd ...
3
votes
1answer
2k views

How to open or import .sdc files in QGIS?

I have some .SDC files i want to look at but i dont have arcview installed. is it possible? i couldnt even find a software that does sdc to shp conversion. any idea? i am using qgis 1.7.4 on both ...
3
votes
1answer
3k views

How to correctly specify coordinate system?

Using QGIS v. 1.9 (1.7 does not seem to be available for Ubuntu Linux 12.04), do the following: Create new project, specify coordinate system by clicking on button in bottom right hand corner, ...
3
votes
1answer
1k views

How to get the layer list back?

Sorry for the probably stupid question, but I closed a side panel I had, where I had a list of layers and which I used to switch on and off layers, and I cannot find how to get it back. I have tried ...
3
votes
3answers
2k views

How to generate heatmaps with QGIS1.9 plugin automatically?

I created a few heatmaps with the new plugin in QGIS 1.9, but now I would like to generate a lot of them automatically. How should I do? I created a few of them by hand, but I should first import the ...
2
votes
2answers
105 views

How to use `layer.getFeatures()` in a standalone script?

I am following the QGIS Cookbook and this post where it concerns reading attributes from layers. I would like to exploit this method and implement it into a standalone script. Essentially, I want to ...
2
votes
2answers
80 views

What is the “best” way to automate the GIS slope and aspect algorithm?

I am currently obtaining slope and aspect of roofs using ArcGIS as follows: Mosaic several Lidar .asc files to new raster Extract by mask using Mastermap building outlines to get hold of just the ...
2
votes
1answer
96 views

Polygon centroid coordinates update error

After a week of unsuccessful fighting I'm forced to ask for your help. I have created a table 't_excavations' with fields 'id_excavation', 'geom' (MULTIPOLYGONE), 'longitude', 'latitude' CREATE ...
2
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0answers
74 views

QGIS 2.8 Raster Layers Moved [duplicate]

I recently downloaded QGIS 2.8 and opened an existing project in it to check how it handled it and make any changes required. This project includes several raster heatmap layers. My problem is that ...
2
votes
2answers
95 views

How to convert a vector map to raster in Qgis?

I am creating a thematic map (vector data) with different classes. How to convert this vector map to a raster map, keeping the classification?
2
votes
1answer
83 views

Combine Shapefile with address information

I downloaded a UTM32 shapefile (.cpg, .dbf, .prj, .shp, .shx file, where other available georeferences are GK3 and TM32) that shows the exclusive division of Germany in its municipalities. Above, I ...
2
votes
1answer
71 views

Layer properties dialog in my QGIS plugin

I am developing a plugin which should display some information like geometry of the layer, feature count etc. Now those are currently displayed in QMessageBox.information. I want it to be displayed ...
2
votes
2answers
78 views

How to disolve lines from same layer?

How can I dissolve lines from the same layer so there are no borders in the junction? For example, a crossroad shouldn't have any border (not as seen in the picture). Can you help?
2
votes
1answer
52 views

How does the QGIS construct class intervals?

I'm using graduated style of a point layer to assign a colour ramp to symbols (squares). I assigned manual values to class intervals specifying classes to be: 0.60 - 0.80 0.80 - 1.00 That is, in ...
2
votes
1answer
41 views

Coloring multilinestringzm M values in QGIS

I have output from a geophysical technique that produces X,Y,Z and scalar value for millions of points, which have been stitched together appropriately (by networkx if it matters) into ...
2
votes
1answer
60 views

Merge multiple bus stops with same name

my question is similar to this one, but it's not answered sufficiently: How to merge points (bus stops) in QGIS manually or programmatically? I have OSM-transit data with bus stops. Some stops have ...
2
votes
1answer
144 views

QGIS Python script for creating project file

Is there a way to create QGIS project file(.qgs) using only Python script outside QGIS Python console.I am trying to publish a map using QGIS Web Client using python. For this, I am trying to do below ...
2
votes
2answers
118 views

QGIS equivalent for ArcMap join for purpose of distances from points to polygon?

It is relatively easy to calculate distances from points to a polygon in ArcMap by doing a join and selecting the option for creating a field containing the minimum distance information. i.e. it ...
2
votes
2answers
277 views

How to customize the QGIS default GUI using Python?

Is it possible to hide/remove/customize the default UI of QGIS from a Python plugin? I want to add my own menus and toolbars and remove some included by default in QGIS. If it's possible, which ...
2
votes
1answer
76 views

How to compute orthodromic distance in QGIS?

I have opened a geotiff file with QGIS. The CRS of this file is EPSG:3857 (web mercator). When I use the distance tool in the menu, the computed distance is towards web mercator coordinates and not ...
2
votes
1answer
237 views

Why can't I open .asc files in QGIS?

Further to my earlier question, I have .nc and .asc files of crop area and production for maize, rice and wheat. It says here, about QGIS importing .asc files: QGIS has native support for this ...
2
votes
1answer
101 views

QGIS print composer, DMS grid when SRC is not in decimal degrees

I have a QGIS project where the layers are in projected SRC, and when I go to the print composer to draw the grid, the units are in millons of meters, and I want them in decimal degrees. Is it ...
2
votes
1answer
114 views

Add OpenLayers layer from QGIS's Python console?

On QGIS 2.4.0-Chugiak the Openlayers plugin is found under Web menu rather than the Plugins menu. How can you use the Python console to add a Openlayers Google Maps layer? The following code give us ...
2
votes
1answer
75 views

QGIS select reversed geometries

I have a road network and a geometry for each road direction. One Geometry from A->B and another Geometry from B->A. This geometries are covering each other. Is there a tool available in QGIS to ...
2
votes
1answer
242 views

create polygons and fishnets of specific size and orientation and buffers

I want to study 6 areas in the field and in order to do so I want to divide each one of them into smaller areas/parts. What I would like to do is find an average square or rectangle area surface ...