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

learn more… | top users | synonyms (1)

5
votes
2answers
439 views

How to filter the MouseWheel event in a QGIS C++ plugin?

I’m developing a C++ plugin for Qgis and I want to filter/override the mouse-wheel event. I created a “maptool” to select a polygon feature on a vector layer, the feature has two attributes : an id ...
1
vote
1answer
536 views

Join attribute table

I am using QGIS 1.7.3 on Mac and when I try to use the tool "join" in the properties toolbox, I have no possibility to add a name for either the file or the field used to join tables. Has anyone ...
5
votes
1answer
537 views

How to calculate Line Density in QGIS?

I have a map of fracture distributions over an area and I would like to calculate the density distribution of fractures that intersect a moving window with a specified radius. Is there a way to ...
7
votes
3answers
5k views

How to speed up working with QGIS or is it slow?

I am a new QGIS user and I am curious about how slowly it is performing; it is possible that I'm asking more of it than I think I am. Here's what I think is the relevant information for assessing ...
1
vote
2answers
421 views

How do I batch export maps for sub regions of a dataset with qgis?

I have a national level dataset consisting of polygons, polylines, points and rasters. I would like to export a map for every sub region (border defined by a polygon shapefile). Is there a simple way ...
2
votes
0answers
74 views

Is there a way to link eVis with time manager in QGIS

I have a point vector layer created from way points of a GPS. I then used the eVis plugin to view geotagged photos for each of these point. I also used the time manager plugin to play through the ...
6
votes
4answers
4k views

How do I convert a polygon into a point?

I want to convert polygons into points. I know how it's done in ArcGis and I think this may sound trivial but it's a serious issue :/. I'll appreciate any hints :)
2
votes
1answer
2k 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, ...
4
votes
1answer
332 views

Can I create a legend of a map that I had get from a WMS?

Can I create a legend of a map that I had get from a WMS? Can I create a legend of a raster map with Qgis version 1.7.4, or only with the 1.8 version?
15
votes
3answers
3k views

Visual Impact Assessment in QGIS or GRASS

Is it possible using QGIS or GRASS to perform a Zone of Visual Impact assessment? E.g. where can a 100m high structure be seen at a viewing height of 1.8m within 30km, taking into account elevation ...
4
votes
3answers
1k views

Where is the Heatmap Plugin

I have read the questions about creating heatmaps but I cannot find the Heatmap Plugin in any of the repositories or using the fetch python plugins, it simply is not there. Could someone please tell ...
4
votes
5answers
5k views

Why can't I add most plugins under Ubuntu 12.04?

I loaded QGIS into 12.04 with much trouble but it works. Although I do not seem to be able to load most plugins. I go to fetch plugins and most are not loaded so I try to load some and they will not ...
2
votes
2answers
1k views

1'' DHM: Hillshade is too rough - how to “generalize”?

I got this hillshade from my DHM (I used the hillshade-module from qgis). For my purpose there is too much relief detail (roughness). How can I get rid of this in QGIS or GRASS? Thanks! Martin
3
votes
1answer
1k views

How to prepare or normalize raw shape (.shp) files for Openlayers use

Hi all it seems like I am having difficulties in normalizing raw map files' resolutions to openlayer's use most probably in parameters mapext and imgext. I hope you can help me with this. Using raw ...
1
vote
2answers
10k views

How to convert coordinates from meters to decimal degrees?

I have a shape file. The coordinates (Lat/Long) are projected as meter (555000, 155000). But, I want to re-project it to decimal degrees(51.523666, -0.07467). How can I do it with ArcMap or Quantum ...
1
vote
1answer
735 views

Why does QGIS Profile from Line tool give me the same value for every point?

I'm trying to make an elevation profile with QGIS's Profile from Line plugin. But when I do, the resulting points all have the same value: -32,767. I'd like to know what I'm doing wrong. My elevation ...
1
vote
1answer
3k views

QGis 1.7.4 on Ubuntu 12.04

Will there be available stable version of Qgis 1.7.4 in Ubuntu 12.04? Version 1.9 is working fine at the moment, but as it is unstable yet, dont want to risk with my work. Thanks.
5
votes
1answer
6k views

Adding Layerfiles (.lyr) to QGIS?

At college we use ArcGIS Desktop 10, but that does not function on my Mac so I have QGIS there instead. I want to do my exercises with QGIS, but we use .lyr files with ArcGIS Desktop, and they are ...
3
votes
1answer
960 views

How to create a Hillshade model with multicolor “alà IMHOF”?

I would like to make a Hillshade-Model with multicolor "alà IMHOF". That means, I dont want a "usual" gray hillshade, I would like to use grey-blue and grey-violett from different sun directions. ...
3
votes
1answer
242 views

How to join interrupted river lines?

I have a vector map that I converted from a raster, representing the rivers in the map. However, because the colours in the map were very diffuse, the resulting vector map has many interrupted lines. ...
5
votes
3answers
2k views

How to create a user map from CSV?

I dont even know if QGIS is the right program for what I need.. What I need: I need a program with maps(Denmark to be specific), that I could feed with a database of users through a CSV file.. e.g. ...
9
votes
2answers
5k views

How to add Direction and Distance to attribute table?

anyone who can help. i just want to add direction (Bearing: i.e N 25 35 E) and Distance (Length: 125 meters) as my new field in polyline/line data. is there a plug-in to generate these fields? i tried ...
1
vote
1answer
1k views

How to delete a column of a shape file in QGIS? [duplicate]

Possible Duplicate: How to delete fields in QGIS? How to delete a column of a shape file in QGIS?The "Delete Column" tool is not highlighted even in editable mode.
1
vote
0answers
45 views

How to load GeoJSON files directly onto QGIS? [duplicate]

Possible Duplicate: Plugin or script to get QGIS to display geoJSON in a layer Is there a way to do this? Or is there a way i can put it onto PostGIS and then load it onto QGIS? I actually ...
1
vote
0answers
376 views

how to create shape file table from text file in QGis python

I have a text file with all field information how can create new polygon shape file table with the text file.. text file having following content.. NAME LAYER GM_TYPE KML_FOLDER ID PERIMETER ...
6
votes
2answers
535 views

Random value calculation in QGIS

Is there a way to do a random value calculation within a range in QGIS? I have been able to do this within ArcMap Field Calculator with the following code: Dim max, min max=20 min=5 ...
1
vote
0answers
78 views

Is there a plugin that collects and allows you to just “turn on” open layers?

I'm thinking on a similar approach as gapminder.org, only that this plugin would contain GIS-data, not only statistics. I'm specifically interested in if there is a plugin like this for QGIS. If ...
2
votes
2answers
436 views

How do I create a negative to positive value raster with neutral 0?

I have a raster layer with a band with values from -137 to 9229. I want to create a color scheme showing how far from 0 the positive numbers are in one color, and how far from zero the negative ...
3
votes
2answers
262 views

How to visualize this country data in Qgis?

I have a csv table, with data in this format: "name","country". Country code is in the same format as the world map SHP file attribute table (both are in the ISO standard). I learned how to join the ...
3
votes
2answers
579 views

How can I reproduce Getis-Ord GI* hot-spot analysis tool in QGIS?

I'm trying to find a hot-spot analysis plug-in for QGIS that would perform similarly to the Getis-Ord (Gi*) hot-spot analysis tool used in Arc, but have not been successful. Does anyone have a ...
3
votes
1answer
823 views

In QGIS map composer, how do I get the Item Properties dialog back?

Yes, well if there is button there, one is bound to click it.... I closed both the Item Properties dialogs in Map Composer. And I can't get them to give me any joy no more... QGIS Trunk
2
votes
2answers
509 views

Configure QGIS to show only the toolbars wanted.

I friend of mine who are using QGIS in their organization for non GIS-experienced people asked me a question the other day that I didn't knew the answer to. He would like to configure QGIS to only ...
1
vote
1answer
264 views

How to handle geometry change in Vector Layer?

Hy, I'm building a plugin in python that manage some lists of wkt from different intern sources (web services, bd, etc..). I can display every source without any problem. For displaying them, I use ...
1
vote
2answers
125 views

How to display a single in a group of nodes with same attributes?

In QGIS, if I have some nodes with a name attribute is there a way to display only one node that would be in the middle of this group of nodes having the same name? For example, let's say i have 3 ...
3
votes
1answer
354 views

GPS problem in QGIS

I have a very strange problem that I cannot understand. I am trying to put together a demo-laptop with QGIS and gps. On other computers I have it working as expected, but on this particular box ...
2
votes
1answer
734 views

How to use SQLite db with QGIS plugin?

Hi I would like to use SQLite for storing some information in my plugin for QGIS. I have a problem: if I put the db let say test.db among the resources as file, after compilied the resorce.qrc file, ...
2
votes
1answer
571 views

How do I automatically fill a table column?

I would like to solve basic problem. I need to automatically fill the table. How is in Qgis possible to fill it like : if column SPECIES contain string DOG -> write to column CODE integer 1? Thanks ...
1
vote
1answer
443 views

ImportError: cannot import name QgsVectorFieldSymbolLayer

I am using QGIS 1.7.4., downloaded April 2012, but receive an import error loading the class QgsVectorFieldSymbolLayer. As i understand this class has been added in the Python bindings on 2011-11-15. ...
5
votes
2answers
923 views

How to generate reports from a Shapefile?

i hope i can describe my problem. I´m into planning a guidiance system for hiking. And like it is, there will be signs with poi and the distance etc. on it. I´m collecting the data in a shape with a ...
1
vote
1answer
222 views

Why are layers not lining up with others with the same CRS? [closed]

I am creating a project on the UK and have downloaded various shapefiles. When I add a vector layer they are coming up as if they are not lining up. Some layers are nicely on top of each other with ...
1
vote
0answers
141 views

Polygon symmetry detection

I was wondering if there was any way to create main axis (axis of symmetry) lines for polygons. I have polygons that represents buildings. I will want to find main axes (axis of symmetry) for those ...
4
votes
2answers
595 views

QGIS affine - form of equation

I am at the mercy of a govt authority who have provided utility information in a cad format with a 0,0 origin and a nonsense grid. About a dozen files, the grid and origin are entirely arbitrary. To ...
2
votes
1answer
106 views

Keeping a vector layer always on top

I want to know how to keep a layer always on top of other layers! After adding a vector layer ( QgisInterface->addVectorLayer ), I want that layer to always be displayed on top of layers added later. ...
4
votes
1answer
2k views

How to get point attribute from polygon layer?

I have two layer, one (A) has point features and the other (B) has polygons. I need to produce a new table with some (the ID) or all the fields from the A table and some (the area code) or all from ...
5
votes
2answers
389 views

Display of zoomable image thumbnails instead of symbols on maps

sincere congratulations on your ingenous QGIS and the many extremely useful extensions. In my research on African archaeology I work a lot with geotagged pictures (drawings; photos; plates etc.) which ...
3
votes
3answers
766 views

How to create svg line style in QGIS?

I need to draw an telephone or energy lines as is done on the polish-core map. Thelephone line was drown by the polyline. I tried the SVG symbols, when I have a lot of single-lines, for each I 'put' ...
3
votes
1answer
613 views

Hyperlinking in QGIS - Add Data to current window

I am looking to add to my current action in QGIS so that a hyperlinked file will open in the current QGIS window, rather than in a new window. Here is what my action looks like: "C:/Program Files ...
1
vote
0answers
94 views

How to maintain schema when copying feature from layer 1 to layer 2, where both layers have same schema?

If I load two unique layers, wherein each layer contains unique data, but both layers share the exact same schema, why is it when I copy a feature from layer 1, and paste it into layer 2, the ...
3
votes
2answers
450 views

Why does the attribute Table not maintain input data?

for a longer time I have a problem with the attribute table. I create the polygons on the map, I fill up the table with attributes. Then, if I click "save", all the data from the table are being ...
3
votes
4answers
2k views

How to ceate a point layer from a table in PostGIS?

I have a table in PostgreSQL(postgis). This table has latitude and longitude values in it. Now I want to plot these point in qgis. The only thing I could get done was connecting to the database from ...