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

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0
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1answer
148 views

QGIS bar chart with labels

I am trying to get a simple bar chart on my QGIS 2.6 map. I have done that with diagrams. It seems to me it is not possible to add simple values to each bar (say there are three bars at a point). I ...
5
votes
1answer
446 views

Why are all tiles white when using the OpenLayers plugin?

I installed the OpenLayers-Plugin and set the CRS to EPSG:3857. When I go to Web / OpenLayers plugin I get the menu with the various maps, but whatever map I choose, all the tiles are white. The ...
1
vote
1answer
50 views

How can a QGIS user plugin reflect the events of UI?

I am developing a plugin for QGIS 2.8 which uses the data of the active layer. It has a dockable window. When the user changes the active layer, the contents of the plugin window's widgets must ...
2
votes
2answers
148 views

Conditional Value Map widget in QGIS

I am looking for a way to implement conditional value mapping in QGIS. This means that the values available in attribute number 2 depend on the value provided in attribute 1. Example: If the user ...
1
vote
1answer
72 views

Merging small area units [duplicate]

I am working with population data organised in parish units for the whole of Denmark. Many parishes are very small (ie <500 inhabitants compared to a median of around 1500) so I plan to merge these ...
1
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0answers
126 views

QGIS/GeoJSON: Dissolve featurecollection consisting of polygons and multipolygons into a large multipolygon

I've read this question. I would like to know how to do this in QGIS. I have a Geojson file with a featurecollection, starting with: ...
2
votes
1answer
297 views

How to change no data value from -32768 to -3.40282e+38 in raster in QGIS?

I am trying to change the null values of a raster from -32768 to -3.40282e+38 in QGIS. I tried using warp tool setting the no data values to my desired number but it did not change it. Then I used ...
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2answers
196 views

Is there any library can perform polygons buffering/ inflating/ merge/ overlap at server side?

I have a set of polygon data express in lat long. I would like to perform some tasks (polygon buffering, inflating etc etc ..) in server side and output the result to client side (client is a web ...
0
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1answer
78 views

QGIS GPS not editing offline database

I have a set of layers from PostGIS that I have converted to offline. I am attempting to edit them via GPS. If the layer is point data, then I can add in that data without issue. However when I go to ...
1
vote
1answer
183 views

How to sum up values within grid polygon in QGIS?

I have a grid full of hexagons that I am trying to bin points. However, instead of using the Vector > Analysis Tools > Points in Polygon which counts the number of point inside each hexagon, I'm ...
0
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2answers
49 views

Should I be able to open personal DB converted to MSSQL as a MSSQL Layer?

I'm feeling like this should work, but I'm banging my head against the keyboard, the documentaion and the google as I can't find any examples to follow for MSSQL. I have 3rd party data only in an ...
1
vote
1answer
241 views

PyQgis, styling vector layers in different canvas

I'm developing a QGIS plugin and I need some help with styling layers in different canvas objects. In my dialog window I've got two QgsMapCanvas objects canvas1 and canvas2. Layers from registry are ...
1
vote
1answer
166 views

PostGIS: Is it possible to identify overlapping polygons in the same layer using their geomteries?

I have a single table containing the geometries of ~3 million polygons and I am looking to calculate the number of polygons that overlap with another. I know that you are able to do this in QGIS ...
1
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0answers
125 views

Generating regularly spaced sample points in qgis based on ratio of area

this is my first post on Stack Exchange. The question I have involves generating sample locations in irregular shaped polygons in qgis. In my situation, there are often many polygons in one shapefile ...
0
votes
1answer
26 views

QGIS Grid Union Issues

I am trying to create a choropleth map of ice concentration over Lake Erie. I have data for all the lakes (I can clip it all at the end), which are in a point shape file. I have laid a grid over the ...
2
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0answers
105 views

QGIS's “Points in Polygon” counts zero in every census tract

I am mapping the location of incidents of asthma using QGIS. I would like to count how many points are in census tracts to better understand the areas where asthma occurs most frequently. My map ...
2
votes
1answer
71 views

QGIS add layer not working

I have QGIS 2.8. I open up the database manager, connect to PostGIS, and then execute a query. The resulting query has an id column, a name column, a geom column, and a membership column. I click on ...
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2answers
65 views

Why QGIS Raster clipper does not work on reprojected layers?

I try to clip a hillshade raster and I get this error. The hillshade was the result of a reprojected DEM from WGS84 to WGS84UTM. When I to clip the hillshade or even the reprojected DEM, I get the ...
0
votes
1answer
49 views

vertical and horizontal scales on raster

I have a raster image which is a log. What I like to be able to do is to extract the X any Y points from the raster. That are in two sets of units The ideal outcome would be an output of an x and ...
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2answers
1k views

Convert a tiff Float32 image to 8bit tif (or jpeg) image using GDAL and Python

I need to convert a Float32 tiff image to 8bit format in order to display the image in a web page. In order to do that I need a jpg image but this conversion is not correctly done with GDAL because ...
2
votes
2answers
214 views

QGIS Viewer, QGIS read only?

Is it possible to create a read-only project in QGIS? Or is there any viewer software available for QGIS project file? What I am after is a read-only project that shows and keep labels and rendering.
2
votes
2answers
323 views

How to manage label spacing/density in QGIS?

How to manage space in between labels (or density)? I would like to have less labels in order to have more space in between. The label order is not important. I would like to precise is just for ...
3
votes
1answer
2k views

How to summarize a column in QGIS field calculator

I have data with a column containing a number value, and I want to divide the value of each feature by the total sum of all the values in the column (to get a percentage). So I would like to know if ...
1
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0answers
108 views

Catchment area calculation

I have a conundrum. I am trying to shortlist optimal physical locations in my county for developing recycling centres that serve the population. I have a vector point layer of the centre point of ...
0
votes
1answer
125 views

How to show percentiles in Qgis?

I have a polygon layer with several fields, like: population, wage, age, etc. I would like to show the percentile value for those fields. How can I do that in an automatic way with QGIS 2.6.1?
1
vote
1answer
121 views

Problem rasterizing

I am trying to rasterize a shapefile using the "rasterize" tool in qgis. The problem is that the resulting raster doesn't seem to rasterize correctly... The teal and purple lines show water flow, ...
0
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1answer
227 views

Grid and Graticule in QGIS Print Composer in QGIS 2.8

I'd like to add a grid in the print composer. The problem is there is no visible option like it was in previous version. I mean I'm looking for an option "Show grid?" like in the picture below. I ...
1
vote
1answer
110 views

Is it possible to change extension name TIFW to TFW in QGIS?

In QGIS from the "project-->Save as image" dropdown it is possible to save the current map canvas as Tiff. A world file is also automatically exported. Nice! BUT, I use the TIFF+TIFW in another ...
1
vote
1answer
120 views

Shapefile doesn't fit in CartoDB basemap

When I import some shapefiles in CartoDB they don't fit properly at street level, as you can see in the screenshot. In this case, the shp was generated in QGis with CRS EPSG:29193 - SAD69. I have ...
1
vote
1answer
75 views

How to change rule-based Layer Styles all at once in QGIS?

Let's say I have a layer with buildings which is only shown when the scale is higher than 1:10000. When the scale is higher than 5000, I want them to show its function color (retail, residential, ...) ...
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0answers
45 views

QGIS WMS Server line style

I have the same problem reported here (QGIS WMS Server), i have one project created in Qgis desktop (tried windows and ubuntu flavors), then exported WMS into Qgis server (ubuntu). All line layers are ...
2
votes
1answer
215 views

Can QGIS place diagrams in map legend?

I have this map and I want to put these red circles in the legend of the map according to this form: Is there a way to do that in QGIS? Thanks
1
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2answers
99 views

QGIS: digitized object disappear when filling in attributes

When digitizing, for example a point, the attribute window opens for you to fill in the pre-defined columns/information. But no point is shown in the map while you do this in QGIS 2.6. It was shown in ...
1
vote
1answer
124 views

Spatial Join Error Python in QGIS

I got this error message when I tried to do spatial join. An error has occured while executing Python code : Traceback (most recent call last): File ...
1
vote
1answer
121 views

QGIS print composer and label with svg background error

I have a problem with labels in QGIS. I'm using a background svg for some labels (street numbers). In QGIS, it's all ok but when I use the composer there is a bug (I suppose), because I see some ...
1
vote
1answer
218 views

How to make transparent WMS vector background in QGIS?

I have a WMS vector layer added to QGIS desktop. But the background is not transparent - it is white. How to change that? When I add this WMS to ArcGIS - all is just fine. Here is the WMS link: ...
2
votes
1answer
624 views

What causes wrong placement of JPGs in QGIS 2.8.1?

I have the same issue explained in this post: How to keep georeferencing from ArcGIS when importing raster into QGIS? But my problem is with .jpg files. I have georeferenced with ArcGIS 10.2.2 many ...
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0answers
99 views

How can I change Java version for QGIS?

I have a custom made plugin for QGIS, which uses Java JDK (running on Win7x64). If the JAR file is run through command prompt, everything works great, but when the same command is used in plugin, it ...
0
votes
1answer
106 views

How to export point geomtery geojson from QGIS?

I want export geojson (from shapefile), for leaflet project. But QGIS 2.6 exported geojson is multipoint geometry(leaflet doesn't read that), so its way to export point geometry geojson from QGIS?
3
votes
0answers
71 views

How to make a virtual field function use the same Ellipsoid settings as the normal field calculator?

I have a new shapefile layer in CRS 3857, in a project that has the same CRS. Under project properties, the measure tool is on ellipsoid WGS 84. When i use the field calculator to create a new field ...
2
votes
1answer
116 views

QGIS reprojecting .ecw file in EPSG:23032

I opened the .ecw file with qgis but I found that the ortophoto is 340 mt northern and 150 mt eastern the topographic map. How can I move the ecw?
1
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0answers
47 views

Problems coloring features of file geodatabase in QGIS

I managed to open a file geodatabase (.gdb) in QGIS. The extensions of my data are correctly shown and the attribute table shows all values correctly. However, when I double-click on the layer to ...
1
vote
2answers
80 views

QGIS GEarthView plugin ReactorAlreadyInstalledError

I've been battling to get this really handy plugin working for some time. When I try installing it from plugin manager, I get the following error: "This plugin is broken 'module' object has no ...
5
votes
1answer
297 views

Grass NVIZ has no output in QGIS 2.8.1 ubuntu 14.04

I am trying to use the Grass7 NVIZ algorithm from the QGIS 2.8.1 toolbox, on ubuntu 14.04. I have enabled Grass7 in the QGIS processing preferences. I have compiled Grass7 from source, and Grass ...
1
vote
0answers
42 views

Keyboard shortcut for “delete” object in print composition?

Is it possible to have/add a shortcut from the keyboard to "delete" an object in print composition? I use to add objects from models then I have to print and delete them to add obects from another ...
4
votes
2answers
112 views

How to preserve formulas in XLS cells when working in QGIS?

Opening layers directly from XLS spreadsheets is a very useful (if not well documented) feature of QGIS, but I can't seem to be able to properly import cells where the contents of the cell is the ...
1
vote
1answer
293 views

How to replace characters to eliminate encoding errors?

Working with Qgis, I have a table representing streets. Attributes inlude street name, length, pavement and some others. Unfortunately, all names with ä or ö or ü display 'odd characters' like Ã1/4. ...
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vote
2answers
74 views

Selecting/Exporting points from one layer that do not overlap with the points from another layer in Qgis

I am working with QGIS and have the following problem to solve: I have 2 point layers. Layer 1 has more points than Layer 2 but all points of Layer 2 have the same position as Layer 1. I need to find ...
0
votes
1answer
78 views

What packages are required to install C++ API on Linux Mint 17?

What packages are required to install C++ API on Linux Mint 17? I already have access to the Python API (installed via “python-qgis” package), but no C++.
3
votes
1answer
264 views

Local Ortho projection to Proj4

We are trying to use proj4 to project a local coordinate system to EPSG4326. We believe we have most of the string created correctly in QGIS and as follows; +proj=ortho +datum=WGS84 ...