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

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Credential Dialog, disabling default Realm information messages disclosing password

I'm using the QgsCredentialDialog for determining user access to the database. When a user is failing to log in correctly the log in credentials are shown in the dialog (Fig. 1). (success, uname, ...
3
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1answer
414 views

Expand raster extent and set expanded values using nearest neighbor sampling

I have run a hydrodynamic model which has given me a grid of surface elevations throughout a bay. I am trying to process the results in ArcMap (or QGIS if needed). My goal is to take the current grid ...
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1answer
70 views

Clipping several raster layers to the same exact size QGIS

I'm new to QGIS, sorry if this is a newbie question... I need to clip about 40 different raster layers from one vector layer (that has the boundaries of 4 neighboring countries) but I need them all to ...
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1answer
665 views

How do i create a flow line map for my data? [duplicate]

I am trying to illustrate a passenger travel flow map from a road terminal to several destinations on a road layer. I have QGis and ArcGIS, but I don't know much on how to start the work. I already ...
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2answers
463 views

Automating the production of GPS-compatible map tiles from georeferenced raster maps

I have a set of TIFF maps that I want to load onto Garmin GPS 62s units. The maximum size for each tile on the GPS is 3Mb and less than 1 million pixels. I manually produced one tile, following this ...
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1answer
95 views

How to convert this geometry location format to a qgis usable format?

I am a beginner with regard to dealing with gis information, so please bear with me. I would be obliged if someone could help. I have data on asssembly constituencies of Delhi, with these ...
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2answers
529 views

How to increase label size of OpenLayers plugin basemap layers?

For QGIS 2.2.0-Valmiera, how does one increase the label size of OpenStreetMap layer or any other basemap layer? Presently the labels are way too small to read. For example, I find that for the same ...
2
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1answer
127 views

Intersection of polygons QGIS 2.2

I have a polygon layer with many circle polygons in it, which are overlapping each other. I now would like to cut of the overlapping areas at their cutting edge: I use QGIS 2.2 and couldn't ...
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0answers
24 views

Why is node tool deleting unselected points in lines?

I am freehand editing lines to a shapefile on Mac QGIS 2.2.0, and have my snap settings at vertex and segment @ 20 pixels. The lines are roadways and I have merged them all into one feature and merged ...
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0answers
41 views

Error openlayers plugin in qgis [duplicate]

I did the following steps: I put the projection in 3857 and I enabled the project on the fly Open a vector shape layer in the projection 4326 I enabled the openlayers plugin Clicked enabled ...
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1answer
142 views

Question about BNG coordinate systems

I'm historically a user of MapInfo Professional but have recently started using FME and have been talked into now testing out a copy of QGIS. The main problem I've come across is that the coordinate ...
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1answer
72 views

why can't i export geometry data from a shapefile?

I saved the layer using "vector save as" box but even when adding GEOMETRY=AS_XY in the layer box, the csv only showed the id and no gemetry data.
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1answer
171 views

Importing data from Excel into ArcGIS/QGIS

I have downloaded the hourly solar radiation data from NREL which is in CSV format but the problem is that the file does not have an exclusive column called latitude and longitude. There are 100s of ...
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1answer
566 views

Replacement of QVariant and setAttributeMap in PyQGIS

I am updating a plugin for QGIS 1.8 to QGIS 2.x. I have the code below. The setAttributeMap does not exist anymore. I have replaced it with fet.setAttributes and it seems to work. When using ...
2
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1answer
324 views

Why do layers appear in the wrong order in QGIS 2.2?

I have a problem with in which order my vector and raster layers appear in QGIS. I have raster that I want to be the background of my other layers (vector). I place the vector layers on top in the ...
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2answers
598 views

Exporting PDF from QGIS with print composer without destroying fonts

So I'm making this nice map with a lot of labels which are going to end up in a book. Since the labels doesn't end up exactly where I want them I'd like to move them some in Illustrator after ...
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0answers
26 views

Link/unlink buttions in the Attribute Table's Form View

Toggling the edit button, in the Form View/Table View, buttons for adding/deleting a record is available. Two additional buttons are also available (Fig. 1). From the look of the icons they perform ...
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2answers
34 views

how to put a cropped selection of a map into the composer

I have a map canvas and I want to have a portion of that canvas printed. I adjust the canvas window in QGIS to show what I want to print and then add the map to the composer. The results are very ...
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2answers
1k 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
49 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 ...
0
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1answer
296 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
69 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 ...
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2answers
128 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
47 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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1answer
196 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 ...
2
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1answer
281 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
106 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?
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2answers
126 views

How to change class break schemes in QGIS to eliminate overlap

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
223 views

Properly clipping shapefiles in QGIS [closed]

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
104 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
14 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
434 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
67 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 ...
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2answers
106 views

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

When displaying the demographic datas from INSEE ...
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1answer
152 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
163 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
29 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
395 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
131 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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2answers
312 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
52 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 ...
3
votes
1answer
378 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
votes
2answers
60 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 ...
3
votes
1answer
103 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
686 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
173 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
99 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 ...
2
votes
1answer
61 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", ...
3
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3answers
227 views

How to apply a specific Rendering to a Raster 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 ...
1
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1answer
92 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?