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

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2
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1answer
93 views

How to have QGIS show the number of points that overlay the raster polygon?

I have a number of single-value raster layers defining a area mask and a point layer pulled from PostGIS. Is there a way to have Quantum GIS show me the number of points that overlay the raster ...
3
votes
1answer
254 views

How to import or incorporate formated Excel tab into QGIS print composer

I would like to know if there's a way to import formated Excel Tab into QGIS print composer. Below is an attachment of formatted Excel tab example I has been asked to display on qgis map composer. ...
1
vote
1answer
259 views

How to “Merge Selected Features” with python?

I have been looking for the answer to this question for some time now, but can't seem to find it! My problem is straight forward: I have one layer It contains lots of features (only polygons), say ...
3
votes
1answer
123 views

Is it possible to use different symbols instead of colours in one shapefile in QGIS?

I want to show 50 bird species on a map and give each species a different symbol (with a different colour) so they can be visually distinguished in the map. Is this possible?
4
votes
1answer
473 views

How to repair and clean contours from high data resolution (lidar)?

I'm unsuccessfully trying to make a bathymetric map with contours extracted from Lidar data at 1 m resolution. The extracted contours have a lot of artifacts like dangles and islands. First I used ...
2
votes
1answer
323 views

Integrate QGIS into Hadoop cloud is it possible?

It might be very basic question. Can I integrate QGIS +Hadoop cloud? Currently I am going through similar question and few research articles & researching on my side. In upcoming ArcGIS 10.2 ...
1
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0answers
53 views

QGIS automatically inserts segments when editing polygon nodes

I have created a shapefile with multiple polygons. When I attempt to move one of the veritices with the node tool new sements automatically appear that cross the polygon and even cross the opposite ...
1
vote
0answers
258 views

How to debug QGIS Server WMS “Download of capabilities failed”?

Currently I am using a QGIS server with a linux Centos system. I am attempting the create a WMS in QGIS and upload it to my website. I have followed the instructions in the "Quantium GIS User Guide: ...
3
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0answers
35 views

Why are there changes in location when printing inserted points?

Añadí una capa de texto delimitado por comas y luego agregue una imagen satelital de google earth. Realizo un diseño de impresión y al imprimir cambia la ubicación de los puntos en varios metros. Cual ...
1
vote
1answer
112 views

Digitized vectors don't match while zooming [duplicate]

I'm trying to digitize in QGIS with Google Maps as the background. Digitizing with constant zoom works fine. But if the zoom is changed, the digitized vectors don't match the Google Maps background ...
5
votes
1answer
94 views

Is there an Attribute Table Feature limit?

I am copying a table with 11,000+ features but only about 700 show up on the QGIS attribute table. Is there a limit? how can I avoid this problem? Thank You in advance!
0
votes
2answers
290 views

Select / Deselect and Identify Features in QGIS

Sorry if this is all a bit 101, but I'm new to QGIS. I basically have a large Arc project that I can access in QGIS for reference, so will only really be using it to identify features. For example to ...
4
votes
1answer
156 views

How to print selected features in QGIS?

I have a detailed map in qgis (vector, .shp) and I would like to split the map in four parts based on attributes to print each part of the map separately. Unfortunately, I didn't figure out how to do ...
3
votes
1answer
199 views

Masking/removing polygons from shapefile

I have a shapefile containing the road traffic noise of a city. The shapefile has 5 columns, where 'noise_in' (noise interval) ranging from 1-5 is included. I want to remove/mask the road noise from ...
1
vote
1answer
102 views

Adding points with defined intervals in QGIS [duplicate]

I'm trying to make a grid with points of defined intervals (e.g. 5 m). How can I achieve this with QGIS?
1
vote
1answer
182 views

What are use cases of Esri's CityEngine?

I would like to know the use cases of Esri's CityEngine, and what distinguish this tool from the other standard GIS like ArcMap and QGIS? and in which fields could be used ?
1
vote
1answer
66 views

How to combine use gradient symbols for layer properties excluding 0?

I want to visualize my data by using graduated symbols. Now, there are some objects with value "0", they should not be printed on the map (which I solved by using rule-based symbols). But, anyway, "0" ...
1
vote
0answers
266 views

problems uploading data onto qgis cloud

I am using QGIS 1.8.0 on a windows 7 machine. Trying to upload a project onto QGIS Cloud. I have 2 issues. Firstly when i go to publish a map it directs me to upload the data. As i am using a free ...
5
votes
1answer
315 views

Georeferencing a jpeg in QGIS but the scale is way off

I've gone through the really helpful walk-through(s) of how to georeference a jpeg in order to make it a layer, but after inputting the coordinates (either by typing in actual coordinates or clicking ...
2
votes
0answers
123 views

Covering a Polygon with Minimum number of circles with fixed locations

In QGIS, I have a vector polygon of a fixed size and shape. I also have a set of circles of a fixed radius and fixed location, which cover part of the polygon. What I would like to do is remove as ...
2
votes
0answers
190 views

OziExplorer maps not rendered correctly in QGIS

When I open up some OziExplorer (.ozf2) maps in QGIS they are not rendered correctly in that they appear reversed or in-versed. Text on the map is not legible and looks to be in-versed but this is not ...
4
votes
2answers
2k views

QGIS import polygons in CSV

QGIS 1.8 on Mac: I'm hoping to migrate several dozen local maps from my 30 year old Win3.1 plotting system to QGIS. Polygons are in X,Y (CSV), first point repeated at the end to close it, with ...
3
votes
1answer
233 views

How to upgrade QGIS Capiapo to Lisboa?

I want to upgrade my QGIS version to the newest one, Lisboa, but I'm not sure if I should uninstall Capiapo first. Is there a way to upgrade without uninstalling? Thank you.
0
votes
1answer
49 views

Deleting QGIS CRS

I've created a new CRS on QGIS but I assigned a wrong name mistakenly to CRS's name. Now I have the CRS defined but the name of the CRS is wrong, or not easily identifiable. I was wondering if ...
0
votes
1answer
87 views

Reuse same style settings for chloropleth maps based on different datasets

I am new to QGIS. I have been using MapInfo for a couple of years, but I am considering to switch to QGIS. So far I like it, but there are some things that I haven't found out yet. I want to make ...
1
vote
0answers
75 views

What is the main benefit and drawback of: GeoServer, MapServer, Mapnik? [duplicate]

For the purpose of creating a comparison table, please recommend a couple of feature fields that would apply to each FOSS GIS server. And, perhaps answer the question of which desktop GIS System, ...
1
vote
1answer
124 views

Does each road segment need to be digitized into a separate entry for a road network?

I am trying to understand this code in pgRouting for creating topology: CREATE OR REPLACE VIEW road_ext AS SELECT *, startpoint(the_geom), endpoint(the_geom) FROM road; CREATE TABLE node AS ...
4
votes
2answers
747 views

How to automatically reloaded raster layer if source is changed in QGIS?

How to automatically reloaded raster layer if source is changed? (The path is the same but inside source file are changes) I use: qgis.utils.iface.mapCanvas().refresh() but layer not refresh. # ...
4
votes
2answers
559 views

Official source for QGIS icons or banners?

I am going to use maps and analysis results generated by QGIS in a presentation. Besides citing the official reference i want to show a small QGIS icon or Banner on the first slide. I found some nice ...
0
votes
1answer
388 views

min and max values are not correctly calculated for DEM

I'm working with DEM in QGIS and need to know the min and max values of my data. In the Properties window, under the Metadata tab, the statistics section shows such values. However, I usually find ...
1
vote
0answers
768 views

Google Earth export from QGIS

I'm using Quantum GIS. Is there a way to export a shapefile to Google Earth format (*.kmz) using QGIS? Thanks.
0
votes
0answers
100 views

What are the rules for digitizing roads for creating a road network?

I want to create shortest route tool using pgRouting. But I digitised roads in a random manner. Shall I need to give a separate row for each road segment?
1
vote
2answers
209 views

Multiple labels in QGIS QML

I've a GML file from the Ordinance Survey which includes a Cartographic Text layer which I'd like to load and render in QGIS. The layer has attributes which are intended to be use for the font size, ...
2
votes
0answers
323 views

QGIS SPIT errors loading shapefile into PostGIS

With QGIS 1.8 on Windows 7, I just installed PostgreSQL / PostGIS and tried to load my first data into it, a shapefile using SPIT, but failed: ERROR: Geometry type (Polygon) does not match column ...
1
vote
1answer
662 views

QGIS Plugin Windows

I have written a QGIS plugin (RTools) which acts mostly like a independent plugin (minimal interaction with QGIS core functions). On Linux both QGIS and RTools were build using QT 4.8 on Qt creator. ...
0
votes
1answer
168 views

How can i select many rows from a table?

I want to create an action that select many rows from PostGIS table to show many lines in QGIS. How can i select many rows from table with python to add these rows in a layer? Thank you
9
votes
1answer
626 views

Is it possible to show our custom message in QGIS Status bar using python?

Is there any way to show our custom message in Qgis Status bar using python? Just like in arcgis "IApplication.statusbar.message(0) = "Please wait..." like that is there any option to show ...
2
votes
1answer
214 views

How to use WHERE CLAUSE to filter the features by its attribute in PyQgis?

How to Get features by their attributes (similar to Iqueryfilter in arcobjects) in Qgis using python? Instead of getting all features and filter it manually, is there any option to use whereclause to ...
3
votes
1answer
157 views

How to determine the longest side of a polygon in QGIS?

Is there a possibility to determine the longest side of a polygon with QGIS? As I need to do that for hundreds of polygons I would prefer an automized method (like a plugin). So far my idea was: ...
2
votes
1answer
173 views

How to get a message when the map is moved in QGIS?

I want to get a message when every time I move the map. I had: def info(self): QMessageBox.information( self, self.tr( "Info" ), self.tr("info") ) I suppose that used to be something like ...
1
vote
1answer
130 views

Polygon Nodes do not have separate coordinates [duplicate]

I'm attempting to measure the distance of a series of points from a smaller number of polygons. As a first step, I've changed the polygons into points along their border, via the Vector> Geometry ...
1
vote
2answers
125 views

How to make digitization more detailed afterwards with QGIS?

I digitized already two areas, bordering each other on one side. Than I realized, more detail was needed! What do you suggest as a fast way to do so? Adding each time new dots/verteces takes so ...
0
votes
2answers
472 views

I can't export in QGIS a Shape file to PostGis

When I try export a pipe network shape to postgis i get this error: Problema inserindo feições do arquivo: C:/PP/gvSIG_Projects/Shapes/Abastecimento/QGIS_VATROCOADUTOR.shp Ocorreu um erro no banco ...
3
votes
1answer
1k views

How to import QGIS Raster into PostGIS

I have created a IDW heatmap using QGIS 1.8.0 and need to import the raster into PostGIS 2.0.1. QGIS saves the raster layer as a .asc file. How do you import the raster into PostGIS as a Raster? What ...
7
votes
4answers
1k views

How to get features based on their attributes using Python?

How to Get features by their attributes (similar to Iqueryfilter in arcobjects) in Qgis using python? Instead of getting all features and filter it manually, is there any option to use whereclause to ...
2
votes
0answers
139 views

qgis missing menu bar ver 1.8.0-lisboa on ubuntu linux

QGIS emits the following warnings when starting, and fails to display the main menu bar. $ qgis --nocustomization Warning: loading of qgis translation failed [/usr/share/qgis/i18n//qgis_en_US] ...
2
votes
0answers
130 views

Why do most Area Calculation result in 0?

I would like to autocalculate area (acres) for a shape file that is in UTM zone 16 CRS. I have tried the "Vector|Geometry Tools|Add/export geometry columns" and also the field calculator. The first ...
2
votes
1answer
616 views

How to fix erros loading result layers from SAGA functions in Sextante?

Using QGIS 1.8.0 and SAGA When trying to use the IDW function from Sextante SAGA 2.1.0 64bit, I get the following error: Could not load layer: C:/test.tif. This error seems mysterious to me, any ...
1
vote
0answers
126 views

Creating polygons for a choropleth map using PostGIS

I have a grid of points, each with a value to it as shown in the image below. The data was retrieved from PostGIS and rendered in Quantum GIS. The final result should be a polygons of a choropleth map ...
1
vote
0answers
126 views

How to programmatically change an SVG symbol in the Vector Layer?

I'm trying to change the symbol used in a layer via Python. I've been able to tunnel through a vector layer to the symbol layer, but I don't know how to change the symbol it's using. I'd like to ...