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

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175 views

Installing Orfeo toolbox for QGIS?

I installed QGIS through OSGeo4W 64 bit version in Windows 8. QGIS installed correctly, but I cannot add the Orfeo Toolbox. Any suggestions?
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1answer
70 views

How to extract and save polygons by attribute in QGIS?

I have a shapefile layer from a vegetation mapping project with 417 polygons that represent 21 different vegetation classes. These are stored in a single column called 'type'. I want to break the ...
2
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0answers
208 views

How to clip a big shapefile from another shapefile's extent

I am working on mangroves in Sundarbans (Bangladesh / India), using Landsat pictures. I need to equalize them in reflectance, before classification, for the evolution of the biomass in this region. I ...
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2answers
38 views

Pacific NW Projection Issues

The basic issue is that I have shapefiles saved in WGS84/Pseudo Mercator (EPSG: 3857) and some DEM data saved in NAD83/UTM Zone 10N (ESPG: 26910), but can't get them to line up. I'm using QGIS and ...
3
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1answer
793 views

Is there a way to export the style, along with a shapefile, to a kml in QGIS?

I see there were plugins in the past that may have done this such as qgis2kml and qgis2google, but they no longer exist.
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1answer
131 views

Displaying trailing zeros to right of decimal in label using QGIS?

is there a way I can get zeros to show up in my label when they come to the right of a decimal in a number such a s 270.00? I'm trying to display two decimals in all my numerical labels, but QGIS ...
3
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1answer
189 views

Add comma to number labels, multiple records in attribute table

A QGIS question: How can I insert commas in 4 digit numbers in an attribute table that has multiple records, with some numbers that are only in the hundreds? It's for an animation so multiple labels ...
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0answers
66 views

QGIS and QT library- code compilation problem [closed]

So, I am trying to workout an GIS standalone application using QGIS and QT C++ Libraries on linux(ubuntu 15.04). I am following this tutorial: https://github.com/qgis/QGIS-Code-Examples Taking the ...
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1answer
1k views

Connect to an ESRI Personal Geodatabase (*.mdb)

My environment: Windows 7 Professional: Service Pack 1 64-Bit QGIS: QGIS-Version: 2.8.2-Wien 32-Bit Microsoft Office 2010 Professional: 32-bit I want to connect an ESRI Personal Geodatabase ...
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3answers
223 views

An Overpass query for OSM ways; both part of a relation and also a specific tag?

How do I construct an Overpass query to find data on Openstreetmap which is both part of a relation and has itself a specific attribute? Specifically: I'm wanting to find sections of cycle route (in ...
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31 views

Merge multiple buffers [duplicate]

Is there a possibility to merge multiple buffers into one single buffer? Illustration: I would like the green buffer to be of one single piece.
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1answer
45 views

Different values after clipping

I have a satellite image from Landsat TM. I want to clip my area so i created a polygon and thru Qgis --> raster clipper I am trying to clip my area of interest. I noticed that the results have ...
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1answer
51 views

Copying the visual shapes from another layer to the current one, while keeping the current layers' database

There are 2 layers that have similar shapes but small differences. I want to keep the shape of layer 1 while having the data of layer 2, which includes more data and it will be animated using ...
3
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2answers
245 views

Expression for placement of label 'offset from point' by azimuth field using QGIS?

I need help making an expression for labelling points, such that the label is placed in one of the 8 quadrants (above point excluded), based on the azimuth field of the point. For example, if the ...
1
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1answer
63 views

show point, based on coordinates, on a map in QGIS [duplicate]

I would like to enter coordinates (e.g. UTM longitude 323519 & UTM latitude 3777727) by hand into QGIS and have it identify that point (either by centering the map on that point or, better yet, by ...
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0answers
154 views

Importing KML Google Maps files with custom data tables to Qgis 2.4.0

I am trying to visualize the complete attribute table of an exported Google Maps KML file with a customized data table, but QGIS won't parse the added information correctly. This is what I can read ...
4
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1answer
172 views

Ignoring certain data values in graduated maps

I'm working and creating a large amount of maps using the latest version of Qgis with vector files and corresponding data sheets. Usually, there will be missing values which is usually easily avoided ...
2
votes
1answer
73 views

QGIS TimeManager with multiple features at one time?

Since the data I have to deal with is really large, it is not practical to separate every feature into one line in the CSV file. Is there any way to animate them as a whole layer? I have ...
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0answers
19 views

Learning QGIS Resources [duplicate]

I am mainly an ESRI user but want to begin branching out into opensource solutions. I wanted to start looking a QGIS and was interested to know what other resources people were using to learn the ...
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0answers
112 views

Equal Area Projection for Indonesia - Standard Parallels

I am trying to do area computation stuff over whole of Indonesia and as such, am using the following projection: http://spatialreference.org/ref/esri/asia-south-albers-equal-area-conic/ To make this ...
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1answer
98 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 ...
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1answer
110 views

Make diagonal grid in QGIS, divide square into squares

I have square polygon which is aligned under some degree and I want to divide this square to, for example, 25 smaller squares, which must be under the same degree in this square polygon. How this can ...
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1answer
68 views

What projection to use for many parts of the world

I'm creating a poster which has many separate maps (rivers of the world). I'd like to use a similar projection for each of them, so they're comparable in terms of shape and size. I guess I want some ...
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1answer
65 views

Where are cpp files from libqgis? [closed]

I am in linux Mint 17.0 I am trying to develop a small application in Qt using libqgis library. When I create a Class inherit from QgsMapCanvas, I get mistakes related with 'undefined references ...
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0answers
55 views

Extra white space in ASCII file due to Translate GDAL from QGIS Modeler

Could anyone enlighten me why do I get an extra white space in from of my first column in an ASCII file generated through a model? With ArcGIS it doesn't happen. Output raster type: Int32 Output ...
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2answers
363 views

How to run Processing qgis:extractbylocation?

I try to use the processing 'qgis:extractbylocation' in QGIS 2.8.2 from the QGIS algorithm provider. import processing # import the layers by a given uri inputlayer = QgsVectorLayer(uriTr.uri(), ...
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0answers
18 views

calculating total area of multiple polygons in qgis [duplicate]

I wish to know the total area of all polygons within a shapefile layer. So far I have added a new column to the attribute table that shows me the individual area of the polygons.I tried to copy the ...
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0answers
59 views

QGIS Convert polygon to point with attributes AND resetting incremental values

Im totally new to QGIS and having trouble with model builder. i am trying to convert polygons to points. Each point must have the attributes of its parent. each point must also have: 1) an ID that ...
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1answer
277 views

How to split polygon features using an overlaid polygon layer in QGIS?

I have a polygon layer (pictured below) that I made by vectorizing a clip from the USDA Cropland Data Layer. The low resolution of the USDA layer causes fields that are separated by narrow roads to ...
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1answer
190 views

set the transparency layer group with Python

How can I set the transparency for all layers within a group of layers? I assume this will require the use of a FOR loop in the Python Console. Based on How to set the transparency for multiple ...
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0answers
93 views

Georeferencing reversal of image

I georeferenced a map and it posted to canvas as a mirror image of the original map. I set my project CRS before starting and also made sure to set the same SRS for the Geotiff being created and ...
0
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1answer
85 views

Assigning circle colours to map using QGIS?

I am trying to make a map showing which zip codes are served by which hospitals. There are five hospitals and each can serve one or more zip codes. I'd like to show each zip code with a dots of ...
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22 views

How to split polygon layer with another polygon layer in QGIS? [duplicate]

I have a polygon layer representing agricultural fields, but it was generated from a sloppy raster layer that failed to represent narrow roads separating fields. I downloaded a vector layer showing ...
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2answers
85 views

QGIS - Edit Surface DEM to Add Buildings

Okay, let me start by saying I'm no expert in QGIS, I'm more into engineering. I'm building a 2D hydraulic model and I would like to add the building footprints (elevated) to my DEM, so flow will go ...
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1answer
91 views

Output Raster r.cost.full values

I am having troubles interpretating the output of r.cost.full. Currently i am working on a project comparing some arcgis tools with qgis tools (workflow and output). One of my examples is to make a ...
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0answers
56 views

QGIS symbology to ESRI

Does anybody know how to export the layer symbology from QGIS into a format that can be used by with ESRI products? I have been successful in exporting an XML but it quotes the file type as: !DOCTYPE ...
1
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1answer
183 views

How can I dissolve adjacent polygons based on minimum attribute value? [duplicate]

I'm trying to merge the polygons (administrative boundaries) in a dataset untill they reach a minimum value. Lets say that the polygon dataset consists of the number of people per polygon and I need ...
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1answer
173 views

QGIS - How do I stop automatic ANSI_1252 to UTF-8 encoding when adding a DXF layer?

I have a DXF file encoded in ANSI_1252, with object attributes containing umlauts. When I open it in QGIS, the umlauts don't display properly. This apparently happens because QGIS automatically sets ...
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0answers
537 views

ImportError: No module named sip

I have been trying to write a custom application to generate contour from QGIS. This is my starting code: import os; from qgis.core import *; This is the error i am getting: Traceback (most recent ...
1
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1answer
75 views

Column length editing in QGIS or ARCGIS

Can anyone suggest how I can change the length of an existing column (For ex. column name -- ABCD, column_Type -- Text, Length -- 254). It would be great to have solution on platforms like ArcGIS or ...
4
votes
2answers
310 views

QGIS Function editor calculate area after transform

In the QGIS function editor, it is possible to transform geometry using transform(geometry,'EPSG:xxx','EPSG:yyy') - however there isn't an area() function to recalculate the area of this. The reason ...
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1answer
76 views

Using Advanced Python Calculator in QGIS Modeler

I'm trying to create a column with integer values based on a small function that basically uses conditional statements. In short, a reclassification. My attempt below: def getValue(Etat): if Etat ...
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0answers
45 views

Split boundary into grid of N cells (equally sized cells)

I am new to GIS and QGIS, although I have a postgrad in maths and am a software developer/architect. I recently downloaded world from Natural Earth, uploaded the data into QGIS and split by country ...
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1answer
192 views

Installing QGIS on Mac OS X 10.6

Could someone kindly explain how to get QGIS (any stable basic version) on my old Mac (OS X 10.6)? I'm completely new with QGIS and all the instructions that I can find beats me.
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1answer
42 views

Exporting output in ASCII from a QGIS model

I'm trying to find a geoalgorithm in QGIS's Graphical Modeler that can convert and export a vector to ASCII. Could anyone enlighten me if there's an option for that? Perhaps through some script but I ...
1
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1answer
156 views

How to detect coordinate reference system (CRS)? – I cannot display two vector layers in QGIS at the same time!

When I in QGIS try to display layer (a) together with another layer (b) that differ in their CRS it doesn’t work. Both are vector shapefiles. I have tried both with using QGIS ‘on the fly’ CRS ...
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0answers
70 views

QGIS Pipe Flow and Aerial Photo

I am completely new to QGIS and We had the survey pick for drainage pipes and pits. We have Upstream and Downstream invert level for each pipe. Wondering if any one could help with step by step, set ...
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0answers
148 views

QGIS - Pop-up menu not displayed when right click on a layer in layer tree view

I'm developing a custom QGIS application using the QGIS API. I've been using the API provided with QGIS Brighton (Version 2.6.1) and have been developing the application in Python in a Windows 7 ...
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1answer
103 views

Problem with writing input and output for QGIS user script

I need to write QGIS script, which removes features with same value of specific attribute - in output will be only features with first occurrence of value. I know, how to check duplicity, but I don't ...
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1answer
226 views

QGIS fails to clip and produces empty shapes

I've seen this type of question a few times and have tried all the different suggestions but no luck. I have 2 layers, one polygon and one line. I want to keep the lines based on a selected polygon. ...