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

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27 views

Derive Z-coordinate

I use an GNSS receiver with RTK-support. In my field computer I use arcpad 10, when I make a shape-file with points I would like the attributes to be x,y,z coordinates or some other way to get x,y,z ...
1
vote
1answer
49 views

Rectangle polygon is displayed as triangle

i am wondering why a rectangle polygon that i have created on an official german surveying website (downloaded as compressed shape in a zip-file) is displayed as a triangle when loaded in qgis. mighty ...
0
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1answer
111 views

Blank Shapefile output?

When executing the following command string in the active browser, Qgis projects the triangle polygon and associated attribute table correctly. Upon reopening the shapefile in a new browser, the ...
1
vote
1answer
200 views

OpenLayers Plugin with on-thy-fly-transformation causes wrong coordinates

I am using the OpenLayers Plugin with the maps from Google Satellite. In Qgis I have chosen on-the-fly-transformation into WGS 84. But the WGS 84 coordinates in Qgis are now 0.15 degrees further E ...
0
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1answer
120 views

Programmatically set layer properties Python Init function

Is it possible to set the layer properties Python Init function field programmatically? I've been looking through the qgis 2.2 api but can't seem to find anything on it. Hint, suggestions and ...
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0answers
54 views

GPS positional, and quality data collection using QGIS

I was wondering if it was possible to record the position along with some of the quality control data in a table when using the GPS information functions to collect some mapping data. I would like to ...
0
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0answers
125 views

QGIS 2.2 - Oracle Spatial Layer - Offline editing - Not synchronizing

I am sarting with QGIS 2.2.0 (windows, 64b). For my project I imported some layers Oracle Spatial layers (Layer>add Oracle Spatial Layer). Then I convert the project offline as I can't always be ...
0
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1answer
91 views

generate massive shapefiles

I have a shapefile with 1475 records, and I want to generate a shapefile for each record. What can I do to generate them avoiding selecting and exporting each record to do that?
1
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1answer
93 views

How to close spaces within a polygon in QGIS 2.2?

I have a shapefile displaying the borders of several city units. One of its polygons, however, had free space consisting of four vertices in it. I created another polygon inside the free space and ...
2
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3answers
123 views

Mis-aligned shapefiles

I'm a beginner at QGIS and I'm having trouble aligning my shapefiles. I have two datasets: one originally in WGS84 (lat/long) and another in Corrego Alegre/UTM zone 24S. I need to convert the second ...
5
votes
1answer
2k views

Problems installing QGIS 2.2 on Ubuntu 14.04

After major upgrade to 14.04 I tried to purge and reinstall QGIS. Unfortunately I get and error (full listing below) and cannot finish clean installation. Information in the log points errors to ...
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0answers
80 views

Highlight paths between two points

I'm new to qgis and very sorry if this is a simple question to ask. IS there a way to highlight the available paths (roads) between two selected points in a road map(in qgis) ? I want to find the ...
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1answer
135 views

Copy .prj file into QGIS projection folder

I want a custom projection used in ArcGIS be available in QGIS. I have the .prj file copied out of a ArcGIS folder (containing different projections). Now, I want this file to be added into QGIS. Is ...
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0answers
54 views

QGIS Python API: SAGA difference algorithm does not split parts

I am using the QGIS Python API in an external script (platform: ubuntu). Everything works as expected. But when I am using the SAGA difference algorithm within the script, there is an issue. The ...
2
votes
1answer
161 views

Import error when utilizing QGIS's Python Init function

Based on the answer to Referencing Qt UIs external to plugin with python. I'm trying to utilize the "Layer Properties / Fields / Python Init function" to execute a file (test_file.py) that is located ...
1
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0answers
64 views

QGIS API changes from 2.0 to 2.2

I have the same program running on two different machine, one with Qgis 2.0 and the other Qgis 2.2. The machine running 2.2 doesn't seem to render the map canvas. I thought it was how I has creating ...
0
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1answer
78 views

How to delete an edge in QGIS

I have used the Lines to polygons tool to turn a city boundary linestring feature into a polygon. However, the tool has connected some nodes more than one time, resulting in multiple edges . I would ...
2
votes
1answer
201 views

How to style the end of a line?

In the picture you can see, the red lines i added manually. These are the ends of the lines. To distinguish that there is the beginning of a new river segment, i would like to have something like ...
7
votes
2answers
626 views

How to extract vectors from map using QGIS?

I am trying to extract building footprints from a raster map (as shown in the example below). Please note that the maps are out of copyright, have been scanned and georectified by a library and have ...
0
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0answers
67 views

Snag loading Gdal 1.11 for Qgis 2.2, on a Mac

Can't load Q2.2 on a Mac without Gdal 1.11. but when I try to load 1.11 'Complete' version, it fails and gives me an error message to contact the developer. Anyone else had this kind of trouble? ...
2
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0answers
85 views

QGIS is not working with Postgres Plus Advanced Server

We have a problem to integrate GIS software with our GIS database which is populated on Postgres Plus Advanced Server 9.2 from EnterpriseDB. We are using QGIS to maintain and analyze our GIS ...
0
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0answers
28 views

'QgsGraph' object does not support indexing

Traceback (most recent call last): File "/home/kasun/.qgis2/python/plugins/floogin/floogin.py", line 246, in findRoutes path=self.astar.astarSearch(graph, start, end) File ...
0
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0answers
29 views

Change in behaviour of layer extents

I have a class that inherits a vector memory layer, it all works fine a previous version of QGIS, but on 2.2 it no longer works. It either does not know that the layer is WGS84 or getting the extents ...
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0answers
64 views

How to provide one label for multiple polygons?

QGIS 2.2 provides a great deal of control through the labeling override expressions, but I don't understand what variables I can use to generate a single label for multiple polygons with the same ...
1
vote
1answer
33 views

Is there a way to use a variable in a rule-based style?

I have several symbol layers: current: "from" <= 1832 AND "to" > 1832 former: "from" <= 1832 AND "to" <= 1832 future: "from" > 1832 What I'd like to do is be able to change 1832 to ...
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0answers
74 views

Draw polygon shape via Qbutton

Ideally; a Ui Qbutton is needed that will activate map canvas editing to add a polygon via the classic mouse click rubber band method. Upon a concluding right click with the active tool, editing ...
4
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2answers
1k views

Postgis 2.1 error after update

After a usual update progress - "apt-get upgrade" - I can not connect with qGIS to my PostGIS DB anymore. Error in the qGIS logfile: Your database has no working PostGIS support. Erroneous query: ...
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0answers
98 views

Issues creating slope raster layer from a point layer

I'm trying to create a slope raster layer using QGIS 2.0 on Windows XP. I started with a points layer with the Z elevation attribute. I then used the interpolation plugin to create a DEM. But, ...
0
votes
1answer
102 views

Labels disappear zooming IN in Qgis 2.2 Composer?

I have a simple map with a polygon Layer of 2 Polygons. Labeling is turned on, so is the option of "Show all labels for this layer, even if they collide". In the print composer the labels keep ...
1
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1answer
140 views

QGIS Print Composer with ESPG:32615 [closed]

I have imported a PostGIS layer as the only object into my project and set the project and layer CRS to EPSG:32615 (UTM Zone 15N). My layer appears just fine in the work area. When I try to create a ...
0
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0answers
112 views

km measurement in qgis with EPSG 4326

I'm struggling with a small issue. I'm working with the master version of QGIS and I have some layers loaded in my project. All the layer are in 4326 projection and the on the fly option in NOT ...
0
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1answer
58 views

Piechart of a text column from attribute table in qgis

I have this problem: I would like to create a pie chart from a column of a attribute table, and I would like to see this pie chart above the map. The column contains names not numbers (I think fields ...
3
votes
1answer
96 views

Referencing Qt UIs external to plugin with python

I'm developing a plugin that sets up a working environment for a user: loading layers (from db), applying styles and several custom designed (Qt) UI files etc. Primary user interaction is in the ...
0
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1answer
96 views

How to georeference a map - which is in projected coordinate system - using geographic lat long? [duplicate]

We have some hard copy maps which were projected in Gauss Kruger coordinate system (in the legend it has been mentioned). But, the coordinates were given in Geographic lat long (Beijing 1954). In ...
1
vote
2answers
486 views

Replacing raster values in one raster with another raster in QGIS … how to?

I have a raster (DEM) and want to replace a few cell's values with the values from another raster in QGIS. I would have done this with the "over" tool in the raster calculator in ArcGIS. Specifics: ...
0
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2answers
155 views

Geo- referencing Projected coordinated raster with GCS - ArcGIS

I have raster displaying Lat/ Long grid, but map information shows that, it s been mapped in Gauss Krugger projetion/ Beijing 1954. So, technically we need to geo reference the map in Gauss Krugger/ ...
0
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1answer
95 views

QGis and Geomedia via Oracle

When I use both QGis and Geomedia to digitize in the same layer I get some issues in my Oracle table. It looks like Geomedia save my point, lines and polygons as ARRAY, while QGis save it like POINT ...
2
votes
1answer
54 views

Selection of points not showing on top (QGIS 2.2)

is there a way to bring the display of the selected objects on top? I have a large numer of points with a lot of them on top of eachother. When I make a selection through an expression and zoom to the ...
2
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0answers
94 views

Where can I find a comprehensive overview of QGIS geoalgorithms?

i am looking for an overview of processing toolbox / qgis geoalgorithms tools unfortunately the link http://www.qgis.org/de/docs/user_manual/processing/toolbox.html seems to be dead. SEXTANTE ... ...
0
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1answer
56 views

Errors uploading plugin to QGIS python plugin repository

I'm trying to upload my first plugin to: http://plugins.qgis.org/plugins/add/ I keep getting the following error: There were errors reading plugin package (please check also your plugin's ...
0
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0answers
254 views

Split Lines with Points Layer Tool

I asked a question a while ago to figure out how to split a line layer with a points layer using QGIS, but cannot, however, get the accepted answer to work due to limitations of my knowledge and the ...
0
votes
2answers
75 views

Can't get dataProvider object outside of QGIS python Interpreter

Within PyCharm import qgis.core as qgis vector_lyr = qgis.QgsVectorLayer("Point", "distance nodes", "memory") pr = vector_lyr.dataProvider() print pr prints None Within Python Interpreter in QGIS ...
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2answers
149 views

How to compute percent of a field

I have a layer with a column conaining population values. I want to write an expression to compute in a new field the percentage of population each polygon has in relation to the total population. I ...
0
votes
1answer
164 views

Coordinate grid not showing in Composer

I went through every answer that I found here, but am either missing something in them or the question has not been asked. I have a very simple map consisting of four layers, namely contour lines, ...
4
votes
2answers
179 views

Storing SRID:4326 data as Geometry or Geography?

I used OGR2OGR to import SRID 4326 point data into MSSQL Server. Didn't realize that it defaults to creating a geometry column instead of detecting the data as 4326 and creating a geography column. ...
1
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2answers
92 views

How to get a set of all buildings of an OpenStreetMap section in form of single points / Multiple polygons as one point

The objective is to get a set of all buildings of an Open Street Map section in form of single points in a shapfile. I downloaded the section from osm. Imported the section into QGIS (and later ...
1
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0answers
96 views

Open PostGIS layer with QGIS 2.2

I just upgraded QGIS from 1.8 to 2.2 and I am getting some troubles to open a PostGIS Layer. The connection with the server works fine, I can see all my tables, select the one I want to open and even ...
1
vote
2answers
240 views

How to align/georeference distorted vector layers in QGIS?

I've got a shapefile which has been digitized from a strongly distorted historical map, and would like to align it as nicely as possible to another precise shapefile layer. The transformation must ...
0
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1answer
109 views

How to create a grid after merging shapefiles?

Follow up question to QGIS Model Builder Script - Possible to merge layers in a folder? I think I'm missing something very obvious here but can't seem to find it. After merging shapfiles in a folder, ...
1
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1answer
54 views

Why is “Add feature” of the GPS Information tool inactive for some of my PostGIS layers?

Sorry If I rise it again on this forum but I couldn't find any info on limitations/requirements of "GPS Information" tool for QGIS (2.2.0) against data layers. For some layers I'm able to collect ...