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

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27 views

How to work with Microstation DGN v8i files in QGIS?

I have a set of multiple files in DGN format (Microstation V8i). I would like to work with them in Qgis. Since QGIS only support pre-V8i dgn files, I cannot directly open the files. My first idea was ...
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1answer
45 views

Crossover Anaylsis

I am new to GIS. I have a text file with (lat,long) of flight lines. If I view the coordinates, they are points, but I am interested in drawing the path of those points, basically connecting them and ...
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1answer
28 views

How to organize a kml created from a shapefile in QGIS?

I have a shapefile that I would like to export into a kml to share it with my colleagues. This shapefile contains a few hundred polygons. I have QGis 2.2.0 on Windows 7. I would like to create a kml ...
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0answers
41 views

Display postGis query result on Google maps Api [closed]

I have MULTILINESTRING Geometry in Postgis and as Google Api does not provide any way to plot MULTILINESTRING , i'm converting MUltiLINEstring to LINESTRING through ST_Merge function. But when i'm ...
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0answers
21 views

Entity handle from Visio

I have successfully imported the polygons from a Visio diagram via dxf into QGIS by using the "space" shape in Visio (a normal rectangular shape comes through as polylines, not as a polygon). Very ...
1
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1answer
53 views

QGIS 2. Bad layers won't resolve

This is getting worse... I created a project with about 6 vector layers (which I digitised) with some raster tiles. It is stored locally on my Windows 7 PC, running QGIS 2.0 The project was fine ...
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0answers
21 views

Using QGIS ComboBoxManager: adapting for QGIS plugin

I'm looking for more guidance using the QGIS ComboBoxManager module (http://3nids.github.io/qgiscombomanager/). After finally getting the imports correct, I'm trudging my way through learning how to ...
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0answers
20 views

How can I reproject a layer in pyqgis?

I have a problem. I'm currently trying to get the extent of a vector layer in latitude and longitude coordinates in python. The layer is currently in EPSG:3857, so .fullExtent() is not returning what ...
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0answers
20 views

PyScripter crashes at “import processing”

I set up PyScripter latest version, 2.7) to work with QGIS (2.2, OSGeo4W install) following http://chelahmy.blogspot.ca/2011/02/setting-up-pyscripter-for-quantum-gis.html. It generally works well. I'm ...
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0answers
17 views

Generalisation Help for large amounts of Shape layers (QGIS)

I'm sorry if someone has asked this already I just haven't been able to find the right thread. I'd like to re-explore/update: What are the existing solutions to automate generalisation/simplification ...
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0answers
33 views

Is the SAGA tool Basic terrain analysis included in Processing?

I can't find the saga tool Basic terrain analysis in the Sextante/processing toolbox. Is this not included or is there a chance to install it?
2
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1answer
24 views

How to change class break schemes in QGIS

When using Graduated Symbology in QGIS, by default the bounds seem to be overlapping. For example, class 1 shows 0-100.000; class 2 shows 100.000-200.000; class 3 shows 200.000-300.000 where it ...
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2answers
62 views

Properly clipping shapefiles in QGIS

I'm looking for help getting the correct shapefile. I'm working off of the files provided by the canadian government at ...
4
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1answer
77 views

How to calculate flight line intersections?

I am new to GIS, and I have flight lines and I am interested in determining the crossover or intersection of those lines. Can I use QGIS for that and what would be the procedures for doing it?
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0answers
13 views

map composer grid annotation in DMS format [duplicate]

I have digitized a map using CRS EPSG:4326 in QGIS. In Map Composer I set the grid. I can't get the annotation to display as DMS (degrees-minutes-seconds) rather than DD (decimal degrees) format. What ...
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1answer
33 views

QGIS 2.2 Attribute Editor Layout “Drag and Drop designer” Field does not exist in datasource

I am experimenting with a new feature available since version 2.2 "Relations" where Foreign Key relations from a database can be documented, so that the QGIS UI can (auto) generate its Attribute Edito ...
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2answers
26 views

How to add a pie chart based on all (or some) features in a layer?

I have a vector layer in a QGIS project which has about 60 items with various attributes, including a check for if an item is complete. I am trying to get a pie chart showing the percentage of the ...
2
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2answers
66 views

Why does QGIS 2.2.0 displaying triangles instead of rectangles? [duplicate]

When displaying the demographic datas from INSEE ...
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0answers
17 views

Where Can I Find CGA City Engine Documentations? [duplicate]

I Neeeeeed Someone helps meee please to find any documentations about CGA City Engine
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1answer
44 views

Can I download large areas of OSM data with QGIS OSM plugin?

I have OpenStreetMap data loading failure problem. I want to use the Download OpenStreetMap data tool in QGIS. I want to select the extent from map canvas like shown below: . For me, the osm-data ...
1
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1answer
17 views

Alias's in the Attribute Table's Column Preview/Column Filters

We've spent some time setting up alias's in Layers/Properties.../Fields (Fig. 1) for database fields displayed as the column headers in the Attribute Table (Fig. 2). Switching the layout in the ...
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0answers
25 views

Extract coordinates from polyline in QGIS [duplicate]

I have a shapefile with 64 lines with the metadata: General: Storage type of this layer: ESRI Shapefile Source for this layer: C:/Users/toke.nielsen/Desktop/lines.shp Geometry type of the features in ...
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1answer
24 views

Error with Gdal 1.10 install on Ubuntu 13.10

I've installed GDAL 1.9 then upgrade to 1.10 on Ubuntu 13.10 and then now it's error (gdalwarp can work but gdal_translate is fail) gdal_translate ERROR 1: gdal_translate was compiled against GDAL ...
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1answer
35 views

How to isolate certain raster values using raster calculator?

I have a one band grayscale image. It has values 0-63 within the band. I need to isolate some of those values. Is there a way to do this in the raster calculator? QGIS 2.2//Windows 7
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24 views

Check if Openlayer Layer is empty, caused by nonexistence of internet connection?

I use Openlayer Google street map as a base-map in my QGIS plugin projects. i want to check programatically if the layer is loaded or is empty and decide if i load my offline base-map instead of ...
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2answers
32 views

Techniques for Filtering the Attribute Table in QGIS's Print Composer

For the legend of a trail map I'm working on I'd like to show the trails and their lengths. I have this data in the table. The problem is that not all of the features (lines) have a name or length. ...
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0answers
35 views

How to create a point representing a polyline?

How do I convert a line (usually 2 vertices but can be more) into a single point in QGIS? I did it a couple of years ago using a build-in tool in ArcGIS 8 or 9 I think but have no idea how to do it in ...
2
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1answer
38 views

How to sum up polygon area by category?

I have a vector layer of habitats. Each feature belongs to a category and has its area calculated. I'm trying to find out the total area of each type of habitat. I've looked at QGIS "Statistics by ...
3
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2answers
49 views

What is the closest CRS to “Meridiano de Greenwich”

I have a 1906 scanned map that I am trying to georeference in QGIS for Mac. The map has French and English lat-long, indicating them as either "Meridiano de Greenwich" or "Meridiano de Paris." I would ...
2
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1answer
37 views

How do I add a field to a table using the QGIS graphic modeler?

I was wondering if anyone could help as I'm struggling to get anything out of the QGIS graphic modeler. For info I have no programming skills whatsoever. I need to be able to add a new field to an ...
1
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1answer
40 views

QGIS DEM (Terrain models) Mode Slope creates wrong data [duplicate]

I have a DEM raster file downloaded from the USGS site. The file can be downloaded here. I am trying to create a slope raster in percent with the DEM tool in QGIS. The GDAL command is the following: ...
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0answers
26 views

How to use the raster calculator in the processing modeler of QGIS

I am trying to create a easy way to do raster analysis by building a model for two way raster calculations. I have two raster layers that I want to combine into a single raster. For now I've done this ...
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0answers
44 views

Creating Legends for QGIS 2.0 Feature Blend Mode Outputs

I am working on visualizing ~4100 buffered point features. The shading of the buffers is keyed to a field in the data. Because the buffers overlap, I turned on multiply in the new feature blend mode ...
0
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1answer
21 views

Expression to create and populate column based on filtered fields

I wanted to create a column and populate it with data based on data from other fields. If column_1 contains fields which has similar string (eg. field_1 = "Country: UK", field_2 = "Country: US", ...
2
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3answers
88 views

How to apply a specific Rendering to an Image and export to JPEG?

We have a specific process which generate an interpolated single band 32-bit Float Raster in Erdas Imagine (.IMG) format. This process generates an image every hour. We wish to apply a specific ...
0
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1answer
34 views

Create and immediately update field using Field Calculator

You can create fields and once created, populate them with data using the Field Calculator. But can you do both at the same time using an expression? Or must you do it in 2 steps?
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1answer
44 views

How to deal with empty corners in raster when calculating fragmentation index

I have clipped buffer area around coordinate from one big raster (forest cover). Such created raster was loaded in R where PatchStat function (library SDMTools) gives fragmentation index. After ...
3
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2answers
52 views

How to generate Non-smooth/crude Contour Lines in QGIS?

I have an SRTM DEM and I want contour lines generated for specific elevations. This can easily be done using r.contour.level/step etc. but the contours generated are smooth and cover the cells only ...
1
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1answer
48 views

How to create a dock widget correctly in QGIS plugin?

I am building a QGIS plugin and would like to use a dock widget. I have used QT creator to design the UI, with the object type being a QDockWidget. When the plugin is enabled in QGIS the dockwidget ...
1
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1answer
32 views

Mac OS X 10.6.8 QGIS not using user-installed Python 2.7

My QGIS does not recognize the recently installed python 2.7 on my mac osx 10.6.8. it still uses the python version 2.6 that is automatically installed by apple. Opening qgis I always receive an ...
0
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1answer
46 views

Convert Shapefiles to GeoJSON?

I'm trying to convert Shapefiles from the State of Texas Senate Districts website into a GeoJSON file for use with Google Maps API. I'm using Q GIS to facilitate but I can't get the ...
0
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0answers
16 views

Using iface.showAttributeTable() on QgsVectorLayer retrieved by getObject()

I'm unsure if i'm properly using the processing.getObject() function. I'm creating a python processing script for QGIS 2.0 and 2.2, but can't seem to get an attribute table to open programmatically. ...
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2answers
31 views

Creating Many Uneven Buffers

Qgis 2.2, Windows 7 I am looking to create buffers around city lights (the raster). Currently, I have simple polygon buffers around the point layer (oecdminusa), but this is not accurately capturing ...
2
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1answer
46 views

polygons and lines not drawn correctly (qgis+postgis)

i am really new to this so i could use some help.. i load osm file into postgresql and then i connect to the database with qgis t to plot it and i see this it happens to whatever file i import to ...
0
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0answers
16 views

Qgis. I got a error message about sqlite3_step while I was doing tutorial. Help me please

I just started using Qgis. Eventually, I got successful installation of QGIS but I'd been through hell of installation problems. Though, I got this a message from doing tutorial. I was converting ...
2
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1answer
91 views

Is it possible to export cross sections from qgis to hec ras

is it possible to create cross sections along a river in Qgis and than export the data to Hec Ras? Thanks
1
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1answer
68 views

QGIS/PostGIS layer styles

I've made a plugin asking for login credentials to a DB. Once logged in, the plugin is loading some layers from the DB. In the DB there are both admin and "normal" users. I've saved two styles to the ...
1
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1answer
66 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 ...
1
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1answer
29 views

How can I change the coordinate system of gpx-points?

I'm working with qgis, v. 2.0.1. I have some points from a gps device (Garmin) and they already are in the .gpx format. Now I have two problems: First, I can't open the gps-Points with the "gpx-tools" ...
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0answers
45 views

Issue blocking QGIS feature form dialog with Python

I'm not sure where I'm going wrong with this python logic for a custom form in QGIS 2.0.1. There are a few things required by the validation function: that index of combo boxes aren't 0 (first index ...