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

learn more… | top users | synonyms (1)

3
votes
1answer
14 views

Identify all continuous networks in a dataset

I have a set of pedestrian streets for a city. I would like to assign all of the streets that can be reached to one another along a continuous network to a unique group. I am wondering if there’s an ...
11
votes
4answers
3k views

Is it possible to export GeoPDF from QGIS?

Is there any plugin for QGIS which would help me in exporting the map document as a GeoPDF ?
0
votes
1answer
21 views

Using QGIS and PostGIS for multi-user capabilities, similar to ArcSDE for ArcGIS

I have previously used ArcSDE technology with Microsoft SQL Server to allow for multi-user database editing. My ESRI licenses have recently ran out and I have been using QGIS for my GIS work. I am ...
0
votes
0answers
12 views

Querying related tables in QGIS

I have a parcel layer and a table of property sales. I have the two tables related (it is a one-to-many relationship) in a QGIS project so that when you click on a parcel you see all the related ...
2
votes
2answers
31 views

QGIS 2.4.0 marker line interval does not work properly when line is bending

I am trying to style a line using marker line option. When I am using styling the line in the style window everything looks nice as you can see on the print screen bellow. I am using three line ...
1
vote
2answers
43 views

How to draw a polygon given a distance and bearing in QGIS

Apologies if this question has been asked before I'm not come across it. I want to draw a polygon given a length and a bearing, basically a square with lenght 1m. I cant seem to manage it with the ...
1
vote
1answer
17 views

QGIS syntax raster calculator

I'm working with QGIS and I want to reclassify a raster in different ranges. Using the following statement does not work even recognized as valid (2950 <= "dem_tallat @ 1"> = 3050) = 3000 ...
0
votes
0answers
12 views

Exported QGIS composer map using Openlayers base map has city labels shrunken

I've created a map in QGIS composer and I'm using the Google physical base map via the openlayers plugin. When working with the map in QGIS canvas & the composer view, I see city names with ...
2
votes
1answer
23 views

matching shape file to csv within QGIS - all strings

I am trying to link a csv to a shape file using the method as described in this tutorial: http://maps.cga.harvard.edu/qgis/wkshop/join_csv.php It seems to work fine but the problem is that the csv ...
1
vote
0answers
17 views

Guidelines for publishing large datasets on QGIS Server

Can anybody provide simple guidance to publishing large datasets on QGIS server? I have a mixture of shapefiles and rasters to display. Biggest shapefile is 230 MB. Biggest raster is 1.4GB. At ...
1
vote
1answer
205 views

How can I change SQL query through a layer of an action (python)?

I have three layers from three diferent database tables. When I click in other layer I want to change (with an action) the query of that three layers. How can I do that? Thank you
5
votes
1answer
4k views

qgis to local postgis connection - fails

It seems pretty clear I cannot connect to a local postgresql installation out of QGIS. This is my first experience with PostGIS. I am using PostgreSQL 9.0 on a win7 machine. I can see the successful ...
2
votes
1answer
35 views

Visualize overlapping line vertices in QGIS

I am trying to inspect the vertices of some linestrings in QGIS 2.4. My goal is to visualize every vertex of a line and easily find those that are duplicated. To clarify this, for an example line ...
3
votes
2answers
54 views

QGIS Installation on Windows

I'm newbie to QGIS and to this forum. I want to develop application using Qt on QGIS to real time updation/mapping of a symbol using GPS co-ordinates. Initially i have installed QGIS on Windows 32 ...
0
votes
0answers
13 views

How to remove abnormalities from the Green vegetation fraction

Study area was clipped by using the shape file from Band 3 and Band 4. First, Band 3 and Band 4 were converted to at-satellite brightness temperature by using the built-in function in semi-automated ...
1
vote
1answer
105 views

PyQGIS loading layer style with PostGIS

I'm loading layer styles from .qml files in a Python plugin. I'm about to switch to loading them from a non-local postgreSQL db. I've been looking at the (from QgsVectorLayer (v2.2)) ...
2
votes
1answer
418 views

QGIS ->ArcGIS Server configuration possible?

Is it possible to connect a QGIS Desktop 1.8.0 to an ArcGIS Server 10.0 ? and of course publish services on it?. The configuration would be like this Quantum GIS-> ArcGIS Server 10.0 on Amazon EC2+ ...
0
votes
1answer
18 views

osm2pgsql doesn't run in a QGis plugin

I have a problem with osm2pgsql when it runs in a qgis plugin. The function i use looks like this: osm2pgsql = "osm2pgsql -s -d {databaseName} -U {databaseUser} -H {databaseHost} -E ...
0
votes
0answers
17 views

Exporting QGIS Raster/Vector layers into one PDF? [duplicate]

I have seen a similiar post to this a while back (Is it possible to export GeoPDF from QGIS?), and thought I would try asking it again to see if there has been any improvement or new knowledge on ...
0
votes
1answer
97 views

Default workspace in QGIS 2.0

I have been using QGIS for quite some time. It always happens that I change the position of toolbars and panels to make the workflow more efficient. But then when I close QGIS and I have to start a ...
3
votes
1answer
49 views

How do I merge DEM rasters correctly?

I've been struggling with this problem for awhile. Here is a curvature raster to illustrate the problem. I'm using 10m DEM rasters from the NRCS Data Gateway for a large portion of California. The ...
0
votes
0answers
110 views

QGIS 2.0 Plug Repository Connection Failed

I'm trying to connect to the QGIS Official Plugin Repository but the status within the Plugin Manager window is always"unavailable" for the URL - http://plugins.qgis.org/plugins/plugins.xml. I'm ...
2
votes
0answers
25 views

How to build custom CRS to export QGIS to Google Fusion Table

I want to export my layer from QGIS as a CSV to import it into google fusion tables. The problem is the qgis export for the geography column is in the wrong format for what google wants. QGIS ...
1
vote
1answer
170 views

Dissolve large dataset in ArcGIS and QGIS

I have more than 80k point data. I have created few buffer from 1 to 5 km of them. Now I want to get the covered area by 1 km to 5 km buffered range. For this I have tried to dissolve those individual ...
3
votes
2answers
36 views

Locate points that are within a certain distance of other points in QGIS

I need a way of locating all points in my dataset that are within a certain distance of any other point. For example, in the following data set in which EASTING AND NORTHING are British National Grid ...
1
vote
0answers
8 views

QGIS: OSM Landscape layer not printed

I am new in GIS and I am trying to print a new map. If I use Google Street and web layer, it got printed without problem in the composer, but OSM Landscape does not appear on the printed document (it ...
1
vote
1answer
93 views

Why can I only see a default list of KML attributes in attribute table?

I converted a shapefile to kml using ogr2ogr. Glancing at the output, it looks correct -- it has a <Schema ...> and each <ExtendedData> references the schema (I uploaded a snippet here). ...
13
votes
3answers
185 views
+250

Zigzag Line Symbol in QGIS

I'm looking for a zigzag line symbol in QGIS. Is there perhaps an easy way to do this that I'm missing? I have tried creating a marker line using a simple triangle marker (^) and adjusting the size of ...
2
votes
2answers
593 views

QGIS crashes when using dxf to shp converter

this is my first question on Stackexchange. I use a GPS to capture data in .dxf, manipulate it in a CAD program that I know how to use, then the dxf2shp converter (I think Python is mentioned) to let ...
0
votes
1answer
21 views

How to run and debug PyQGIS scripts in PyCharm Community Edition 3.4.1

I am working with creating plugins for QGIS 2.4.0 (Chugiak). I am curious to know how I can write the codes, and debug them in the environment I am comfortable in, i.e. PyCharm Community Edition ...
1
vote
1answer
13 views

Print with different settings of layer view?

Using QGIS is it possible to print on the same paper two windows with different settings of layer? I mean: window1: layer1 ON - layer2 OFF window2: layer1 OFF - layer2 ON
2
votes
1answer
29 views

View with sequence in QGIS 2.4

In postgres, I created a view with a sequence nextval() to have an unique id (called vid). I tried to vizualise this view in QGIS but it failed. It seems that nexval() causes some issue according to a ...
3
votes
1answer
47 views

Distincly color world map by language in QGIS 2.4

For a map of Wikipedia language prefixes, I need to color a map by a country's value in the 'language' column. I. e. all countries with the same language worldwide should share a color, which they ...
1
vote
2answers
683 views

QGis 2.0.1 mapserver extension missing

I tried to export my Qgis projects to mapserver, using RT mapserver extension, because there is not any other extension in my version of QGis.(QGis 2.0.1 Dufour on ubuntu 12.04 LTS). After installing ...
0
votes
2answers
54 views

How to draw a perfect circle with a set radius in meters on map?

Following this istructions on how to draw a circle I can make buffer layer on each point I need. I am not able to draw perfects circle because the buffer will be elliptic? The CSR is EPSG:4326 - WGS ...
2
votes
0answers
26 views

How to calculate surface out of GPS points in QGIS

I have uploaded several squares (which consist out of 4 GPS points, not connected). I need the total surface of the squares. Is there a simple way of doing this? Do I create polygons and than ...
4
votes
2answers
73 views

Wrong $area from field calculator (QGIS)

The area of the polygons in a layer, calculated by the field calculator with "$area" is wrong (much too big) for some polygons. If I draw the concerned polygon again, the area is calculated correctly. ...
4
votes
1answer
55 views

How to split a line in fractions of its length

I've seen a lot of questions involving splitting a line with the help of a point layer. I want to split a line in fractions of its length. For example, I have a line 400 meters long, I want to split ...
1
vote
1answer
14 views

Change QGIS Processing (Sextante) default arguments for r.out.gdal

Lately I've been using r.grow through the QGIS Processing Toolbox on several rasters which represent the whole world with 500m grid spacing. It takes many minutes to save the output. The reason seems ...
-1
votes
0answers
33 views

How to load Google Satellite images in QGIS using python [on hold]

I have to write a python program to remove all the existing vector layers in QGIS. I then have to write a python program to load the Google satellite images. Please help me by answering this ...
0
votes
1answer
24 views

How to manage the CRS of Open-Layers plugin in QGIS?

I am working with OpenLayers plugin in QGIS 1.8 but I am not sure on how should I manage thc CRS. The defaul CRS for Googles/Bing layers is WGS84/Pseudo Mercator (EPGS:3857) but I am not sure on the ...
2
votes
2answers
69 views

Can't transform lines to polygons

I have a similar question to: How to join lines in QGIS for later using "lines to poly"? I have a line shapefile that I wish to transform into a polygon shapefile. After making some ...
1
vote
0answers
41 views

Geometric functions in field calculator in QGIS

I had a look in the manual of QGIS and I also browsed the Internet to find some useful information about the geometric functions of the field calculator. I've found this post but I'm still confused. ...
1
vote
0answers
12 views

QGIS PointConnector Plugin - x out of x lines not drawn

Unfortunately every try to generate lines between points (.shp) with ids (1-6) and a csv-file with from - to values failed. Maybe you can give me a hint whats wrong with my workflow? 1) I generated a ...
0
votes
1answer
93 views

How can I copy columns from layer 1 to layer 2?

I have two layers, the first layer is pipe: that has some fields (column) title like : length, id, material. Also I have another layer that is empty (without any fields). How can I copy fields ...
4
votes
0answers
37 views

Why are my calls to SAGA routines in QGIS not working cross platform?

The ability to write and run cross platform scripts for QGIS using python is OUTSTANDING! However, when I try to run the SAGA:MERGESHAPESLAYERS algorithm from a python script it works fine in windows ...
1
vote
2answers
98 views

Importing DWF files into QGIS

I regularly receive files from a service authority in DWF format, which shows the location of their assets in there area. I note that there is no option to have the data in an alternate format as it ...
1
vote
1answer
33 views

How to save multiple layers from QGIS to a Spatialite db?

I thought I had asked this before but I can't find any trace of it. Each time I save a layer from QGIS as a spatialite it insists on creating a new db ( if you select a existing db you are asked ...
2
votes
1answer
33 views

SVG Issues in QGIS API

I'm using QGIS-2.4.0 to developing an application. I created my own custom MapCanvasItem for showing SVG. It is great to load a SVG from symbol library that QGIS provides(such as d:\QGIS ...
0
votes
0answers
25 views

Open a *.qgs project file in API, why maps do not show?

I'm using QGIS-2.4.0 API. I saved a test.qgs file in QGIS Desktop, in this project, there is one layer that is visible in it. Then I open the test.qgs project file in QGIS API to developing an App, ...