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

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QGIS2Leaf Plugin installation error “cannot import name AlgorithmDecorator”

I have been using the qgis2leaf plugin and succeeded in creating interactive maps, adding legend, photos, etc. But suddenly I noticed that the OSM base layer has disappeared and the polygons are not ...
1
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1answer
40 views

How to create a sequence for a table which was created by selecting data from another table?

I have created a new table by selecting data from an existing table: CREATE TABLE polygon2 AS SELECT gid, geom FROM polygon1; CREATE SEQUENCE polygon2_gid_seq; SELECT SETVAL('polygon2_gid_seq', ...
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0answers
17 views

Qgis2leaf doesn't show layers with scale-dependent visibility

When I add layers to the QGIS2LEAF dialog box it accepts it and opens up the preview in my web browser, but when I starting looking for the layers, in this case points for campgrounds, I dont see any ...
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0answers
17 views

QGIS 'Clip raster by mask layer': Problem loading output [on hold]

I'm using QGIS 2.8, currently developing a python plugin and at some point I have to execute consecutive processing algorithms. When it comes to loading the layer created by GDAL algorithm 'Clip ...
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0answers
13 views

QGIS Wien 2.8. Openlayers plugin doesn't work [duplicate]

I have installed the latest version of QGIS wien 2.8. Windows 8.1 downloaded the stand alone version from official QGIS website. I had to uninstall the latest one I had because Openlayers plugin was ...
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0answers
26 views

Transitioning from ArcGIS to QGIS (or other open source)? [on hold]

I work for a small City (under 10,000) that currently has an Arc Enterprise license. I am considering the possibility of steering away from Arc in the future (3-5 year time frame) - possibly to be ...
1
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1answer
15 views

Getting NULL-values when point sampling USGS (SRTM 1 Arc-Second Global) grid (QGIS 2.8.2)

I use the Point Sampling Tool in QGIS to transfer gridvalues (of DEMs) to point features. This goes well with grids from f.i. MapMart (SRTMHARRIS_DEM), but I get only NULL-values when using grids from ...
2
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0answers
19 views

QGIS : transformation types in geo-referencing

Im a beginner in geomatics. I try some images georeferencing in QGIS. I would like to understand what is happening behind the different transformation types (linear, polynomial, Helmert...). What I ...
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0answers
22 views

ArcGIS and / or QGIS and UAV tech [on hold]

I see it has been almost a year since the last "UAV and GIS" question was asked here. Finding some incredible youtube videos recently showing remarkable results doing UAV and GIS together here and ...
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2answers
76 views

Meaning of GCP in QGIS

Im a geomatics student, During a geo referencing with QGIS, a .Points file is saved. I open it with Notepad++ It is written under this form : mapX,mapY,pixelX,pixelY,enable ...
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0answers
13 views

Error in merging two raster files (precipitation) in QGIS

The newly computed geotiff shows the extent of both raster layers, but only the data of one. If I use identify features tool it gives me only the values of the visible part not of the other part. I ...
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1answer
22 views

trigger postgis and dump qgis 2.8.2

I created a trigger that checks if geometry is valid on insert and update. create or replace function check_geom() returns trigger as $$ begin --insert a polygon IF st_isvalid(new.geom) = 'f' ...
2
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1answer
39 views

How to perform viewshed analysis with Dutch AHN files?

i downloaded the new (dutch hight data) AHN files, and was trying to perform a viewshed analysis at some point near UTRECHT. The plugin (grass plugin) works ok, i tried it before with a dem map. ...
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0answers
19 views

QGIS Spatialite Views problems

I am trying to wrap my head around spatialite views in QGIS. However there are severe limitations that make it very cumbersome: Spatialite views in QGIS do no update, if the corresponding tables in ...
1
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1answer
22 views

How can I create polygons for a 3D map from a DEM in grass/qgis

I have a SRTM 30m DEM of my area. I want to create a physical 3D terrain map from it (from felt, 3D printer, you name it). I have two questions about this process: With grass r.contour I created ...
2
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0answers
12 views

How to export from WINSTAR to ArcGIS [on hold]

I have data in a very old "winstar" type of format. However, currently I only use ArcGIS for Desktop and QGIS. Does anyone have an idea on how I can import this old-fashioned winstar stuff to ArcGIS ...
2
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1answer
29 views

How can I copy non-blank values to a new column from different columns in the same layer in QGIS?

My data: n1 n2 n3 NEW_COLUMN 11 null null null 33 null null null 55 My desired result: n1 n2 n3 NEW_COLUMN 11 null null 11 null 33 null 33 null null 55 ...
2
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0answers
8 views

Remote sensing Classification and texture analysis compared with QGIS zonal statistics

Some back round: Using Geomatica to analyse suburban spectral signature in Las Vegas. Ran a texture analysis on all band images. Combined texture bands with original image bands to run an unsupervised ...
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0answers
12 views

Toggle layers on print composition

I want to use QGIS to make several views of bold colors for one same map. I've been using the layers in order to keep one on top of another. How could i make a composition on the print composition ...
1
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0answers
9 views

Change detection between two Landsat scenes? [duplicate]

I want to do time series analysis and find change in NDVI. I have rasters where each pixel is represented by some value at a time. Also I have same thing but represented by points. And I would like ...
2
votes
1answer
33 views

How do I make a hexgrid in QGIS with cell identification numbers

I'm getting started with QGIS as part of my interest in military science and wargaming. I'm running into a problem adding identifiers (column and row) to the hexcells that I've created with mmqgis. ...
1
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1answer
25 views

Using proj to convert EPSG:2263 to WGS84

I have input data in EPSG:2263 with X and Y coordinates such as: X,Y 987043,206407 982441,212359 990907,209020 (these locations are within NYC). I need to convert these to WGS84. Using QGIS if I ...
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1answer
39 views

Merge shapefiles heatmap

I have to merge few shapefiles into one and create a heat map out of it in qgis. I'm a first user of the QGIS, I tried to do it there: vector-management tools-merge files into one, but it kept to make ...
2
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0answers
13 views

Add individual fields to delete-log-trigger when deleting PostGis-Objects via QGis

I am using a PostGres Database with PostGis extension (on Windows). QGis serves as a client to access (visualize and edit) certain database-tables. I need to create a delete-log-table that saves all ...
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2answers
22 views

Load USGS DRG into QGIS

I'm trying to load some DRG data from the USGS into QGIS. The source data uses UTM coordinate and I can't seem to get it to overlay with WGS 84 vector data. I (think) I've followed the recommended ...
2
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1answer
36 views

Adding QGIS feature, that shows coordinates and scale, into a custom application

I'm writing a standalone application using PyQGIS and I'd like to add the QGIS feature that shows coordinates and scale as the cursor hovers over the map. I need to know this mainly in case of ...
3
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0answers
31 views

How to develop QGIS Plugin to fully run Spatial Queries With PostGIS?

I'm developing a QGIS plugin that fully run spatial queries with PostGIS. Actually I developed all spatial queries wish need some adjustment. I'm looking for some ressources or documents to know how ...
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3answers
42 views

Rotating labels in QGIS 2.8.2

I have a question concerning label placement in QGIS. I'd like to rotate every label by 180°. Therefore, I set the rotation value to 180 (I've tried different ones as well as different variable types) ...
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0answers
14 views

GML geometries are not rendered

I tried to view a GML file and I have a problem with viewing of polygons from a feature type ps:ProtectedSite with QGIS. This feature contains a MultiSurface with a surfaceMember with a ...
3
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2answers
36 views

How to fix the error between two coordinate systems?

How do you think the shift of line is due to morphological change of river? Or it is due to deviation between two coordinate systems? Please point out !!
2
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1answer
33 views

Layer Order panel seems to be broken in QGIS 2.10, it duplicates layers

I'd like to just confirm that a problem I am having in QGIS 2.10 is not unique to me. I am using the Layer Order panel to control the rendering order of layers in my projects, it's very useful when ...
2
votes
1answer
20 views

Merge and export two layers that utilize blending modes

I have a new question that I'm trying to solve. Spent more time than I can to admit trying to come up with a solution that doesn't require bringing the layers into Photoshop or the GIMP (which would ...
2
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1answer
34 views

Can I use TIFF files for zonal statistics in QGIS or ARCGIS?

I am completing a remote sensing paper and am doing most of the work in PCI Geomatica, where I have 2 separate files. One from running a texture analysis algorithm containing 6 band layers from a ...
2
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2answers
49 views

How to place coordinates points on a vector layer?

I have got GPS coordinates collected from a number of farms in my country (Malawi). But when I plot these GPS coordinates on a vector layer (my country map) using QGIS, the points are falling outside ...
2
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0answers
16 views

Compare similar lines and update layers

Here there are two layers with the representation of the streets and the idea is: We want to update the most recent layer (with the red line) with some of the data storaged in the other one (the light ...
1
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0answers
20 views

What is the correct way to run a python script in QGIS Open Project macro?

This code (answer from @gcarrillo about other question - Is there any way to freeze the layer names in the TOC?) runs fine on python console and inside a plugin. But now, I tried put it within the ...
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0answers
29 views

Minidump on exit in QGIS (2.8.2- Wien) 64-bit version when using GDAL in plugin

I am working on a plugin for QGIS that is working fine on 32-bit versions but I am having some problems while using it on the 64-bit standalone installation package. I have tried on several machines ...
2
votes
2answers
151 views

Where to download QGIS 2.10?

Is QGIS 2.10 Pisa for Ubuntu/Windows already available?
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0answers
21 views

How to call the Qt UI of a script? [on hold]

I'm pretty new in the python world, and I'm working with the python console inside QGIS (Master version on a Debian machine). I have written some scripts, all of them are in the same directory (e.g. ...
2
votes
1answer
57 views

some shp to dxf converted lines don't show in Autocad

I have a group of vector files that I intend to convert to "DXF" format. But after the conversion, only contour lines(white lines in the red polygon) are not displayed in Autocad. I read some related ...
1
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1answer
32 views

Print composer - legend - graduated

I have a map with graduated symbology, with 328 unique values. I would like add a legend to my map (as in the picture), illustrating that light blue indicates low values and dark blue high values. I ...
1
vote
1answer
26 views

QGIS: drag zoom via keyboard shortcut/ mouse wheel?

to zoom to a rectangle in ARCGIS i always clicked and held the mouse wheel while pushing the control key. This was a very efficiant way for me to navigate through a map. Is there anything similar in ...
1
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0answers
33 views

QGIS - Simplification process creates a new polygon - how to avoid it?

I am trying to simplify a layer made of polygons. I have used different methods but the new simplified layer has a polygon which intersect with itself, thus creating a "new" polygon. Please see ...
2
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0answers
23 views

QGIS QgsLayerTreeGroup signal “currentLayerChanged”?

In a pyqgis context, I use the "currentLayerChanged(QgsMapLayer *)" signal of the QgisInterface class to do something when the current layer is changed, but I need now to do the same when I select a ...
1
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0answers
12 views

How to Change Precision of Export / Add Geometry Columns field

I would like to display the coordinates of a number of points on a map. I can use Vector > Export / Add Geometry Columns which adds coordinates to 6 dp. However as I am using a UTM-type projection ...
2
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2answers
29 views

QGIS Editing: move - both - nodes after Cut has been performed

I just ran into unexpected behavior while editing a polygon shapefile in QGIS 2.8.2. Scenario: A polygon: Then I cut that polygon into two seperate poygons: Then I use the Node Tool to move a ...
1
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1answer
31 views

How to completely uninstall and remove QGIS 2.8.1

I want to uninstall and completely remove QGIS installation from my computer(windows vista). I have uninstalled it and when i try to reinstall it says it is already installed on the system.
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0answers
19 views

QGIS import OpenAIP

I have files from OpenAIP (http://www.openaip.net). How can I import them ? Format available are : .aip .cup .dat .aip is xml file. For point : <OPENAIP VERSION="960678" DATAFORMAT="1.1"> ...
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2answers
21 views

Embed Sound in Leaflet Popup with QGIS

I was wanting to embed some animal sounds in a leaflet map my son and I are creating. Have images embedded, but would like sounds in the popup if possible. Like embedding images, can this be done ...
0
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0answers
15 views

How to create new field using the values of one attribute column multiplied by a constant number in Qgis or ArcGIS [duplicate]

I have point data that has a small length attribute - I want to times this length attribute by a constant number (I need to trial a few different constants) to find the diameter of a protection zone ...