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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1answer
1k views

import qgis.core problem with QgsFeature and QgsGeometry

I've tried several previous answers to similar questions - no luck. I run Win7. I installed QGIS 2.2.0 using the OSGeo4W 32-bit installer. Problem 1) from qgis.core import * failed. Solution 1) ...
0
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0answers
67 views

Why does it take so long to run zonal statistics?

QGIS 2.0 Windows 7 I have pulled agricultural data from NASS CDL in tiff format. I want to track where a certain crop has grown over the years. My intention was to use a county shapefile overlaid ...
1
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2answers
106 views

How to use eVis to launch AutoCAD with a relative path?

I found this post, which leads me towards what I need: How to link to external files with relative path in QGIS actions? Now, I'm trying to use the eVis plugin to open .DWG and .DXF by launching ...
2
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1answer
186 views

Add objects from one layer to another at QGIS

How can I add some objects from one layer to another one. I mean, I have one layer with specific data(e.gg polyline) at the same time I have another layer with different objects .how can I copy/move ...
0
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1answer
89 views

work with emf files at QGIS?

how to convert EMF files to shapefile at QGIS? Actually I have EMF file that has been generated from Autocad-Civil3d. Thanks Hamid
2
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1answer
642 views

How can I copy columns from layer 1 to layer 2?

I have two layers, the first layer is pipe: that has some fields (column) title like : length, id, material. Also I have another layer that is empty (without any fields). How can I copy fields ...
-1
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1answer
475 views

project points to a vector layer and get z elevation at QGIS

one point file and one dtm vector file. how can I project points to the vector file and get z elevation of them. Thanks Hamid
11
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2answers
3k views

Is there a good qml or sld file available for QGIS + Openstreetmap data?

I'm looking for a qml file (or equivalent e.g. sld) to allow me to use QGIS to take Openstreetmap data and produce paper maps. I'm re-asking this question (it was asked once or twice over a couple of ...
1
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1answer
130 views

Are unicode symbols supported in QGIS labels?

I want to use unicode symbols in a QGIS label - is this supported? I.e. I have this expression for labelling a line: case when xat(-1) - xat(0) > 0 then 'GF ->' else '<- GF' end and ...
2
votes
2answers
731 views

Installing LASTools to QGIS on a Mac (or other LAS processing plugins)

I recently saw this link how to install LAStools toolbox to QGIS. The problem is that the instructions are only for Windows users. Now I wonder if it's possible to install LAStools on a Mac with QGIS ...
0
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1answer
44 views

Wich is the way to create serial field following alphabetical order with QGIS?

I have a field with names, a string field, and I want to create another one with serial content following the alphabetical order. I have this: -------- |Field1| -------- | B | -------- | C ...
2
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1answer
308 views

How to fix “update of view in private qgis.db failed”?

would anyone know why i keep getting this error message after installing Valmiera from Durfour? Thanks!
3
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1answer
778 views

QGIS 2.2 problem, loading layer into road graph

I have the road graph plugin installed, but when I try to configure it with the Settings dialogue, no layer names appear in the Layers field. I have tried various shapefiles, but the Settings dialogue ...
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0answers
49 views

How to display a layer's label source column?

I have a CSV layer that displays points on the map. I use one of the columns as the Label. In Print Composer I would like to display the name of the column used to generate layer Labels. Is this ...
0
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0answers
21 views

Creating centreline from polygon [duplicate]

I´´m looking for a tool in Q-GIS that can create a centreline from polygon. Similary to this post: Finding centrelines from polygons? I´m not sure that the Geoprocessing Tool can deal with it. Thx
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0answers
107 views

QGIS convert attribute table to point shape

I have imported an attribute (whith no spatial information) table from MySQL. Fortuantly it has two colums with Longtitude and latitude taken from google maps. Is it posible to use those values to ...
1
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1answer
419 views

QGIS loads PostGIS layers but DBManager can't connect

DB Manager can't connect to PostgreSQL, but "Add PostGIS Layer" can. My eventual goal is to save created layers to PostGIS. I assume I can do this using the DBManager Tool. I can alternatively use ...
3
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1answer
77 views

Cell Statistics in QGIS

Cell Statistics in ArcGIS will calculate the mean (or statistic of choice) among multiple rasters on a cell-by-call basis. Can QGIS do this? If so, how?
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22 views

qgis-web-client Not rendering label fonts

My install of qgis-web-client is not rendering label fonts, each character appears as a black box / square. See screenshot: Tested in FF & Chrome, have tried changing from the MS system font to ...
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0answers
46 views

Matplotlib downloads to override folder

Just completed install of QGIS (2.0.1 Dufour) on a Macbook Pro running on Mavericks via Kyngchaos download page. However, when downloading Matplotlib for the install, while everything ended up the ...
1
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1answer
2k views

How to process MODIS ndvi data using QGIS/GRASS/R?

I have MODIS ndvi data (MODIS_Grid_16 days NDVI) from the iberian peninsula (3 tiles), from February of 2000 to August of 2012 (really big data). I want to know how to deal with this kind of files. My ...
2
votes
2answers
635 views

Is there a way for multiple users to use an SQLite/SpatiaLite db simultaneously?

Is there a way that multiple users can use the SQLite / SpatiaLite database simultaneously? Thank you for your feedback.
1
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1answer
154 views

How to create a hyperlink in one point?

I started to use Quantum GIS 2.0.1 Dufour and I'm still trying to understand how to work with it. I have a shape layer in QGIS made of points, and I want to attach a different hyperlink to each of the ...
2
votes
1answer
83 views

How to make a good table or view for QGIS in PostGIS?

I have a PostGIS db from OpenStreetMap (osm2pgsql) with my custom table. There are two problems with it: When I list tables, the columns from my table are scanned for geometry type, and it takes ...
4
votes
1answer
734 views

Is there a way to run a python script on opening a QGIS project?

I have a .csv file containing financial data which is generated on a regular basis outside QGIS. Then I want to create a PyQGIS script that will add the .csv file as a layer in my project. (The idea ...
1
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2answers
89 views

How can i change the geometry of an existing layer?

I work with Qgis, v. 2.0.1. I have a point layer in which I have structures that could be represented as lines or polygons, but at the moment they are represented as a group of points. I know I can ...
1
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1answer
91 views

naturalearth sqlite db not loading into qgis 2.2 [duplicate]

I downloaded the naturalearthdatabase in sqlite-format (http://www.naturalearthdata.com/downloads/, the downloadlink goes to http://kelso.it/x/nesqlite), but qgis 2.2 (running under win 7 64bit) does ...
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2answers
55 views

How can I determine which polygons contain other polygons?

I am using only free, open source tools. I have two shape files: a shape file of voting precincts and a shape file of census tracts. I want to know: which voting precincts fit inside which census ...
1
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1answer
51 views

How do I get the attributes of a particular polygon in qgis

I downloaded a shapefile that has demographic data for census tracts for a city -- each represented by a polygon in the vector layer. I can click the attribute table icon to see the whole sheet of ...
2
votes
1answer
44 views

Is there a way to get create label classes similar to symbology classes?

Is there any way to get the same classes of label size as by the symbols? For example: i devided towns according to their population to 5 classes (as graduate symbolology), and want to label each ...
2
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0answers
64 views

QGIS Labels: letter or word spacing ignored after export

My line label have letter spacing of 3px (Layer Properties -> Labels -> Text -> Spacing -> Letter). In print composer everything is drawn like I want it but after export to svg, pdf, or image the ...
5
votes
1answer
428 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 ...
2
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3answers
2k views

QGIS Desktop 2.2.0 - program does not start

I just installed QGIS 2.2 (I download QGIS Standalone InstalleVersion 2.2 (32 bit)).Installation was successful without any errors. Then I try lunch QGIS Desktop 2.2.0 but the program does not start. ...
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1answer
97 views

Purpose of “myPlugin_dialog.py” file created by QGIS Plugin Builder

I usually use QGIS Plugin Builder to create working templates for QGIS plugins. While a generic Python plugin needs the files below; __init__.py metadata.txt resources.py (translated from ...
0
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1answer
159 views

Threejs “Failed to generate a dem file using gdalwarp. gdalwarp is not installed.”

I am trying to test out the new threejs plugin for QGis and have come across this error. Failed to generate a dem file using gdalwarp. gdalwarp is not installed. I have installed the latest ...
0
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1answer
103 views

Setting default browser for QGIS actions

I am trying to open a pdf using QGIS action tool with Adobe Reader. Currently, the action defaults to Internet Explorer which doesn't succeed in opening my document. I'm currently able to open AutoCAD ...
2
votes
1answer
498 views

How to select only polygons that overlap with another layer?

I have two shapefile layers created from different thresholds from a predictive model (Pink=80; Yellow=95). Is there a way to create a new layer of only those pink polygons that contain yellow ...
3
votes
1answer
439 views

Got Null values when updating attributes with PyQgis

I'm trying to create and update a field and ,for now, just change it's value to 2. Here is my code: layer = qgis.utils.iface.activeLayer() index = layer.fieldNameIndex("P") # if index == -1: # ...
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2answers
55 views

Is there any way to use open source tools to make sure that lines on a map dont overlap?

I am a generalist developer getting the hang of basic gis. I made this geojson map by clipping and converting different shapefiles. The problem is that the precincts of New Orleans extend into the ...
3
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0answers
250 views

Does QGIS support .sld style files for raster layers?

I'm currently looking at the documentation for geoserver, and I'm trying to load a raster and .sld file in QGIS to see if I can edit .sld files for raster layers. The .sld and raster are located here: ...
0
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1answer
477 views

qgis-web-client stuck on Loading Map

I'm trying to publish a map created in qgis desktop via qgis-web-client. The left hand bar loads with the layers I would expect visible but I never actually see any mapping data just a grey screen ...
5
votes
1answer
557 views

Calculating Topographic Exposure with Raster Calculator

I need you help trying to calculate Topographic Exposure (TOPEX) on a DEM in ArcGIS. I am trying to figure out wind exposure on a DEM with 25m cells. There is a great blog post where someone explains ...
0
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0answers
21 views

Set region around multiple polygons

I have combined multiple objects per row in my layer. Is there a way to build another layer that surrounds the combined objects, per row?See example. For Q-GIS, thx.
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0answers
166 views

Defining the boundary of a catchment area

I digitized contour lines from topographic maps and created a DEM. With the DEM, I estimated the boundary of a catchment area. Estimated positional accuracy of topographic maps is RMSE = 65 m, with a ...
0
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2answers
55 views

Erase within a feature class - Planar enforcement

I´m using ArcGIS v10 ArcInfo. I´m working with a feature class that has 5 features which are waterdepths (1 to 5m). These features are overlapping each other. What I need, is that they are not ...
0
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1answer
92 views

Match bicycle routes to street lines

I have a KML layer of bicycle routes and a street line layer. Using either ArcGIS or QGIS, how can I select the streets that correspond to the bicycle routes?
0
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1answer
155 views

How do I control rendering order of items in composer?

Alternative formulation of the question is: Is there any other way apart from the order of adding items to the canvas of setting the rendering order> The problem is that I want to change the map ...
3
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1answer
2k views

Georeferencing an image with GDAL, based on QGIS Georeferencer Plugin

I would like to georeference an image with GDAL. The image already has a spatial reference set (EPSG:31276). For the georeferencing, I have a list of 4 ground control points (also in EPSG:31276). ...
2
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0answers
31 views

changing central meridian in QGIS causes problems [duplicate]

I want to change the central meridian of my world map (WGS84) in QGIS from 0 to -80. The problem is that this distorts the map every time I try it. This is what I do: go to Settings/Custom CRS ...
0
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0answers
81 views

How to activate edit tools

I have opened a project I worked on earlier on another machine, but the edit tools are not active, so i cant turn on editing to change a layer. What is the reason for them to be gray, and how can i ...