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

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2
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0answers
11 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 !!
1
vote
1answer
33 views

How to merge two lines of polygons?

In QGIS 2.6.1, I have merged two polygon shapefiles. After the merge I am facing a problem at boundaries. So I thought of changing Polygon -> lines, manually deleting one of the lines at the ...
1
vote
0answers
23 views

How to create ROI in Semi-Automatic Classification plugin QGIS

while trying to classify landsat images, I get the following problem: I click on the pixel I want to define a ROI, but the ROI polygon that the plugin creates appears in a different part of the image ...
1
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0answers
5 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
2answers
412 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 ...
1
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1answer
9 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 ...
3
votes
1answer
170 views

How to map flood areas from a set of points containing surface and height of water?

I am working on the damages made by the typhoon Haiyan. I use QGIS 2.0 with extensions and toolbox, and MapInfo. I have vectors, rasters of the place. I want to map the flood area along the ...
1
vote
1answer
8 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 ...
1
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0answers
42 views

Projection for alignments [on hold]

I would want to put on a qgis map some historical sites to check if they are aligned. If an alignement exists, the points should stay on a great circle (is this correct?). I want to visually verify ...
1
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0answers
8 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 ...
0
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0answers
20 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 ...
1
vote
2answers
17 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 ...
4
votes
1answer
382 views

How does QGIS calculate heatmap values?

I made a heatmap from points (with values) in QGIS, and now try to understand what the values in color scale are. Radius 300 map units (meters) Pixel size 10 map units (meters) Point values are ...
0
votes
0answers
7 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 ...
0
votes
0answers
16 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
54 views

Where to download QGIS 2.10?

Is QGIS 2.10 Pisa for Ubuntu/Windows already available?
1
vote
1answer
57 views

Automatically changing the angle of a symbol in QGIS?

I am working with an iron age cemetery in QGIS. I marked every grave in a point layer with several columns; amongst others, burial rite (inhumation, cremation etc.). I inserted a second column for the ...
1
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0answers
32 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
votes
2answers
36 views

Easy Custom Labeling tool: How do I remove label arrows?

I am labeling a lot of features and the Easy Custom Labeling tool is helping me to move every label to the desired position. I also like that the tool adds arrows for labels that I moved but sometimes ...
0
votes
0answers
18 views

How to call the Qt UI of a script?

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
0answers
19 views

QGIS - shp to dxf conversion problem while opened 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
vote
1answer
18 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 ...
0
votes
0answers
16 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"> ...
1
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2answers
18 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
vote
0answers
10 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
votes
1answer
23 views

Error: Algorithm not found (QGIS)

I wrote the following code using QGIS'API. import os from qgis.core import * import qgis.utils prefix_path = os.environ['QGIS_PREFIX_PATH'] QgsApplication.setPrefixPath(prefix_path, True) ...
1
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0answers
18 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
vote
1answer
26 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.
3
votes
2answers
211 views

How to delete column/field in PyQGIS?

How to remove or delete column fields in a shape file using python?
2
votes
0answers
12 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 ...
0
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0answers
13 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 ...
1
vote
0answers
11 views

PyQGIS Standalone Crashes python.exe when zooming out too far / Process finished with exit code -1073741819 (0xC0000005)

I have the following PyQGIS Standalone App which is working fine so far. One little problem is that if I zoom out to the MaxExtent(by scrolling the mousewheel) the app crashes python.exe so that the ...
6
votes
6answers
5k views

Open Source equivalent to Collector for ArcGIS to use with QGIS/PostGIS?

From my reading of the Esri web pages the Collector for ArcGIS is tightly tied to that platform. I would be delighted to learn that I am wrong about this. I have a strong interest in generic mobile ...
3
votes
1answer
17 views

QGIS create a line graph with attributes value on a section through the map

I wonder if I can make cross sections of GIS data (other than height). An example: I have a shapefile of a city with building plots and attribute values of the plot size. I want to choose a random ...
1
vote
2answers
28 views

How to use r.mapcalculator to change values within a raster cost map to negative

I have created a cost map in r.cost module in GRASS (through QGIS). This is actually a distance map from a protected area and distance from protected area has been calculated in both directions. How I ...
2
votes
2answers
186 views

QGIS installation from OSGeoW4: entry point not found in qgis_core.dll

I have installed QGIS through OSGeo4W installation. My operation system is windows 7 64x. I try to start the program QGIS Desktop from start menu this error: Do I need to do something? Installation ...
1
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0answers
17 views

QGIS dissolve by attribute and retain primary polygon attributes

I have a parcel shapefile. Many of the parcels have been combined over time, but the shapefile still represents the original parcel boundaries. The attribute table has a field for the original parcel ...
2
votes
1answer
63 views

Strange circles have appeared on QGIS map?

Why are circles appearing on my map? It started after using QGIS dev build 2.9 and now appears even on 2.8.1. Also I've noticed that the usual list of CRS does not appear while using the dev build. ...
1
vote
0answers
87 views

Processing LAS dataset in QGIS 2.8.2

I need to extract DEM from LIDAR dataset in QGIS 2.8.2. I have installed LAS tools in QGIS. I cannot configure my LAStools because I do not get Processing-->Options and Configuration and instead I get ...
2
votes
1answer
28 views

How to count points within the current Print composer atlas feature in QGIS 2.8?

In the print composer when generating an atlas, does anyone know how to show he feature count per each atlas coverage feature? For example, I have generated an atlas where each map is a different ...
2
votes
0answers
45 views

Remove multiple fields from multiple shapefiles using a python script [duplicate]

I'm using the python console of QGIS 2.8.1-Wien. I have a shapefile with many fields in the table that I want to remove them. I tried to use this geoalgoritm as: ...
1
vote
1answer
63 views

How to load an (updating) point layer from Access?

I have a database table linked to the QGIS project which contains X,Y & Z coordinate information, which I can display in the Map View window of the project, after having used the “Points Layer ...
0
votes
0answers
11 views

Loading geoserver WMS raster layer in QGIS python console

I am using the following snippet to load a raster layer deployed under wms service using geoserver, in qgis python console. I am getting False output. Any idea? registry = ...
1
vote
1answer
33 views

Why is SAGA from the Processing Plugin not recognised?

Similar to this post: SAGA algorithms don't work in QGIS 2.8 except the fact that SAGA does not appear at all in the Processing Toolbox: As a check, I used the Python Console with the following ...
6
votes
2answers
220 views

How to sample a 3D raster along a 3D path (or 4D raster along 4D path)?

I have a 3d raster dataset of atmospheric variables (lat x lon x altitude). I would like to sample this raster dataset along a 3d path. Any idea how I can achieve this, preferable with qgis or ...
1
vote
1answer
13 views

gsb projection file for qgis under MAC OSX

I'm trying to create a new projection inside wgis. The projection includes a gsb file. With the Windows OS is easy to implemnet that: you just need to place the gsb file inside the ...
4
votes
3answers
1k views

Edit Toolbar Became Disabled While Editing in QGIS

My edit toolbar became disabled while I was editing a layer in QGIS. I have closed the window and opened it again to edit, but it is still disabled.
2
votes
1answer
186 views

qgis missing menu bar ver 1.8.0-lisboa on ubuntu linux [on hold]

QGIS emits the following warnings when starting, and fails to display the main menu bar. $ qgis --nocustomization Warning: loading of qgis translation failed [/usr/share/qgis/i18n//qgis_en_US] ...
1
vote
1answer
60 views

How to show a QGis map in Qt/C++ custom widget with QgsMapCanvas?

I'm trying to add a QGis map in Qt/C++ widget using QgsMapCanvas, but I have some problems... I'm working with the following environment: - Ubuntu 12.04 - QGis 2.8.1 - Qt Creator 2.4.1 (based on Qt ...
2
votes
0answers
25 views

Can you load WFS uncached in QGIS

I think this might be a bug, but we've just installed QGIS 2.10 and the WFS seems to be working strangely. When you load a WFS which is not cached the system loads all the visible features as ...