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

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48 views

Creating shapefiles using java?

I have a running java service which gives me a count corresponding to every 5-digit zip code in Newyork state. Now i want to feed this input to QGIS programatically so that the color of every polygon (...
0
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0answers
131 views

QGIS Slow to Save to Network Drive

Do other users find that QGIS is very slow when saving to a Network Drive location? Saving locally is instantaneous, saving the QGIS project to the network takes over 1 minute every time. Saving the ...
0
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1answer
143 views

How to extend a (river water level) raster, transfering its values to the added area?

Exploring the raster tools in QGIS and related software, I found raster buffer functions to surround existing rasters. The values of the raster buffer are restricted to be distances from the interior ...
1
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1answer
115 views

QGIS + GRASS: r.in.gdal “View output” produces “cellhd file (…) does not exist”

I'm working with a recently installed QGIS (2.10.1) + GRASS (6 v2.0) package, and have been working with some rasters and vectors in QGIS that I'd now like to play with using the GRASS tools. I've ...
0
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0answers
46 views

“Handle bad layers” with spline plugin

I´ve been trying to use the QGIS Spline plugin and so far it was going pretty good, though I had a few bumps I got through with help. But now, the layers I've worked with have dissappeared (or have ...
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1answer
94 views

Looking for a QGIS tutorial

I am looking for QGIS tutorials that cover the topics of making a user interface to update the attribute table or any related tutorial that might help. Does anyone know of one?
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0answers
125 views

Georeferencing google earth historical images

I have been trying to raster and georeferenced an historical set of images from Google Earth but I am experiencing issues after done the first one properly. I save 4 images from Google Earth of the ...
7
votes
1answer
269 views

How do I optimise performance on a local QGIS + PostGIS installation?

I'm learning how to manage a local PostGIS (ver 2.1) database, with spatial indexing enabled on the shapefiles that I've imported (using the PostGIS Shapefile Import/Export Manager). I have imported a ...
3
votes
1answer
150 views

How to toggle Map Tips with PyQGIS?

I want to display "map tips" in QGIS with python for my custom map canvas QgsMapCanvas(). How can I do this? I can switch manually with View/Map Tips but it won't work with my custom canvas in my ...
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2answers
58 views

Cannot Select 'Input line or polygon vector layer' when trying to simplify Shapefile

I'm trying to simplify a Shapefile by opening it in QGIS, Go to the Vector menu, selecting Geometry tools, and selecting Simplify Geometries... When I do this I get a modal window that I can fill out ...
1
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1answer
104 views

Problem installing Lizmap web client

I'm trying to install lizmap web client, following the steps present in here: http://www.3liz.com/blog/rldhont/index.php?post/2012/11/06/Test-LizMap-on-Windows-with-OSGEO4W. But unfourtunally i can't ...
2
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1answer
81 views

QGIS 2.8+: How can layer.selectedFeatures() return an empty list while layer.selectedFeatureCount() returns the correct number of selected features?

I noticed some changes since qgis 2.8 but can't find any information about it. Let's say I have a very simple point layer loaded in QGIS, from a spatialite table. From this layer I select some points ...
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0answers
152 views

How to solve UnicodeDecodeError in Python when executing Make Valid LWGEOM algorithm in QGIS?

I'm trying to fix some invalid geometries using the Make Valid LWGEOM algorithm in QGIS 2.8.3 processing toolbox but a Python error occurs: Errore durante l'esecuzione di codice Python: Traceback (...
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0answers
166 views

QGIS 2.10 crashes while working with Qgis2web plugin

Currently I am working on Qgis2Web for editing and generating web maps from my vector data. But after opening the plug in window. QGIS got crashed.
2
votes
1answer
125 views

Saving as TIFF in QGIS?

I made a color composite using Raster > Miscellaneous > Build Virtual Raster in QGIS. The output is a VRT file but I need TIFF. Then I went through Raster > Conversion > Translate. The output is TIFF ...
4
votes
1answer
293 views

qgis 2.10.1. mac - geotiff singleband pseudocolor [duplicate]

i've installed mac version from kyngchaos including all required packages ... ... and just noticed the following: while windows version behaves like expected when trying to render an ordinary tif via ...
0
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0answers
18 views

Visually clipping a search area (MCE) (QGIS)

I have some search areas to refine using a variety of vector inputs. I can clip these to get my end product but it is a messy process. Is it possible to use blending modes to visually "knock out" ...
1
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0answers
30 views

Pixel value of Geotiff image on Qgis different pixel value of input image

I have a binary image. I convert this image to GeoTiff image by python funntion: def exportGeotiff(filename, raster, row, col, xResolution, minLon, minLat, yResolution,geoReference): format = "...
1
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1answer
138 views

Programmatically import new composer from template to project using pyQgis

I am trying to find information about how to programmatically import new composer from template, but it is impossible. There is a lot of information how to print the composer to image, but not save ...
0
votes
1answer
36 views

Measuring different values in latlong Geotiff whether OTFR enabled or not

I'm using a GeoTiff file in QGis that has no projection per-se (it uses lat-long coordinates) and WGS84 datum. Further it has an x pixel size of 2.40475e-07 degrees and a y pixel size of -1.99028e-07.....
1
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1answer
376 views

Label only selected feature using QGIS?

Is it possible to make an expression that labels only the selected feature in QGIS? I tried it with this expression in the label tab: attribute( $currentfeature, 'LAENGE' ) But it labels all and not ...
1
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1answer
166 views

Style Sheets: Setting up a style sheet to change only styles, no other fields

I'm trying to create style sheets for my projects. I only wish to change the Style, without affecting labelling or the Fields. And I can't, for the life of me, get it to work. I'm using .qml files and ...
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0answers
59 views

Run a exe file from QGIS

I am trying to run an exe file from the python console in QGIS. my_aplication.exe is a script made in Python3.4 and 'compiled' to windows exe file import os os.system('C:\Python34\my_application.exe'...
2
votes
1answer
64 views

Processing modeler Output Order

I have a model running on the processing framework it produces a serie of vector layers as output(alt-0, alt-1, alt-2, alt-3, and so on). I have prepared the model keeping the order of these ...
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0answers
30 views

Using the expression builder in the Atlas function in QGIS to group features?

I am trying to show only record in the atlas for the following attribute table... ogc_fid | id | phasename | exampleinfo ---------------------------------------------------------- 2 | ...
1
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1answer
32 views

QGIS--computing local standard deviation (from many bands) to each cell

I have HDF images with 365 bands each. Is there a way to compute local standard deviation across all of these bands with results appearing in each cell? I have tried Zonal Statistics (with polygons ...
1
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1answer
576 views

QGIS Server not working on CentOS 7

I installed QGIS Server via yumex on my CentOS 7.1 System and I have an Apache 2.4.6 Server running. My Problem is, I can't show a QGIS project in my Chrome browser. Of cause, I read many ...
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0answers
88 views

How to add images of buildings inside a map?

I'm going to do a trip and I want to have a custom map on my website. My idea is to have a map similar to this one for example. So I need to add images (svg or jpg) to the base map. I want a clean ...
5
votes
2answers
450 views

Password Protect QGIS project

On a shared computer, I have a QGIS project which links up to a PostGIS database that contains my data. If a user wants to access layers from the db, they have to enter the db credentials, so that's ...
1
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1answer
55 views

QGis aligning to grid north

My first post here. I'm designing a map at 500.000 for Italy and with EPSG 3035 or 3034 (Lambert Conical Conformal) I'm still deciding... anyway... In my map I've several points whose symbol is a sort ...
0
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0answers
41 views

Problem on displaying a layer in overlay on a s57 map

I am loading a s57 file, I select only some layer to be displayed. I am under QGIs 2.8 At this point it is ok, the coordinatereferencesystem is EPSG4326 WGS84 and at the bottom of the windows of qgis ...
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0answers
131 views

Trouble with kernel density estimation

I have been trying to find out how to make the SAGA and GRASS kernel density tools work in QGIS 2.8. I have had a lot of trouble trying to get them to work as they produce useless results seen below. ...
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2answers
125 views

How to interpolate data using quantum gis?

I am trying to interpolate distribution value of rain using IDW (inverse distance weighting) method using quantum gis. What steps do I need to undertake? The input layer data which I used there are 2 ...
0
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1answer
148 views

QGIS 2.10 - Web server - Tiles

It's posible to automaticly generate tiles from QGIS web server ? I need export a project (europe size) from zoom 9 to 13 in png Format in order to use it with leaflet like. I tried many extention ...
0
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1answer
85 views

Importing multiple GPX files without selecting waypoints/tracks/… for each file separately using QGIS?

I've got several GPX files. I'd like to import them into a QGIS project. If I'm going with >add Vectorlayer QGIS asks one for each file, which specific parts (waypoints/tracks/...) to load. I'm ...
4
votes
1answer
213 views

Clip raster by raster with data extraction and resolution change

I need to stack multiple maps (tif) together and clip them all according to extent of one small raster map (second raster at the top of picture below). However, the size of pixels in each map is ...
4
votes
0answers
227 views

QGIS 2.10.1 & SQL Server 2014

I'm struggling to load spatial data into QGIS from SQL Server 2014. I have a table with 4 geography columns (3 are polygon layers, one is a point layer). The table has a primary key column that is a ...
0
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0answers
43 views

Spie Charts in QGIS

I'd like to be able to produce spie charts in QGIS. I can see how to produce 'ordinary' pie charts, but I can't (as yet) see any way of producing spie charts. I've got about 50 places for which I'd ...
3
votes
3answers
806 views

PostgreSQL trouble editing points / lines / polygons in QGIS

I have a problem with postgresql and QGIS : I can add points/lines/polygons and fillup field But I can't : delete points/lines/polygons modify points/lines/polygons (move or modify field) ex : ...
1
vote
1answer
36 views

How can I assign an object in a shapefile to a location based on another shapefile?

I have two different shapefiles to work with: one of them has polygons representing tree canopy data and the other is a shapefile for census tracts in the area I am working on. I am trying to figure ...
2
votes
1answer
44 views

Display 8-Bit Signed Rasters with Negative Values in QGIS / MapServer

When loading 8-bit signed rasters with values from -128 to 127 into QGIS or MapServer, negative numbers are not recognized. Is there a way to change the default display settings in QGIS and/or ...
3
votes
0answers
196 views

QGIS 2.8 Python Plugin Unittest Segmentation Fault 11

UPDATE: This issue may be isolated to my MacBook. The seg fault did not occur in testing on Windows. I have put together a sample unit test for a QGIS python plugin. It is causing a Segmentation ...
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0answers
111 views

Problems using GRASS tools for topology validation in QGIS

I'm working with a shapefile of Enumeration Districts (Setores Censitários) of the 2010 Brazilian Census. Enumeration Districts (ED) are smallest areas for which Brazilian Census data is available. ...
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0answers
45 views

VectoreLayer Still Empty even if attribute has been set with value

I am working with the qgis api c++ 2.8.2, my application is written in QT 4.5.3 / C++ I had to create a vectorlayer in memory with attributes and features and export it to a shp file to import it in ...
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0answers
112 views

How to dissolve a large number of polygons in QGIS?

I'm trying to do it using the command DISSOLVE but it generates an empty shapefile. My purpose is to dissolve a large number of polygons (about 200,000) into a single multi-polygon...
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0answers
25 views

QgsPalLayerSettings is not defined

So I'm writing some script for QGIS 1.8 and I'm unable to resolve this error. from qgis.core import * pallyr = QgsPalLayerSettings() The second line gives me error that QgsPalLayerSettings is not ...
0
votes
1answer
39 views

google maps engine connector

I am trying to use google imagery in QGIS through the Google maps engine connector plugin. I relatively new to QGIS and need some help. What I want to do i use the google maps in QGIS and then print ...
2
votes
0answers
79 views

C++ plugin deployment

I´ve downloaded the C++ code for the qgis_hello_world plugin from GitHUB (https://github.com/thebigspoon/qgis_cpp_plugin_cookbook) I compiled with Visual Studio 2012 express on a win7 machine (though ...
1
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1answer
133 views

QGIS: How to change symbology of a continuous raster to discrete with unequal intervals?

I'm new in QGIS and currently trying to convert my ArcGIS-layers into QGIS. One of these layers is a slope gradient raster. I want to change the symbology so that a specific rang of gradients will ...
0
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0answers
14 views

Donot Polygon in QGIS [duplicate]

When I am creating a polygon inside of another polygon, both the polygons are selected, Please help me to create donot polygon in QGIS.