Tagged Questions

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

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1answer
35 views

How to save multiple layers from QGIS to a Spatialite db?

I thought I had asked this before but I can't find any trace of it. Each time I save a layer from QGIS as a spatialite it insists on creating a new db ( if you select a existing db you are asked ...
1
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1answer
32 views

QGIS: How to get Symbols saved in GPX Files

I have some waypoint layers that contain different types of points and I distinguish these in QGIS by different symbols and colours. I want to export these to a GPX file that I can download to my GPS ...
2
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0answers
25 views

How to move to the next feature in the polygon with user keyboard inputs

I am new to this qgis i have one question. There is one rectangle and it is divided into some 20 grids.I wrote a program to zoom into the each feature.but if i am in one feature i want to move to the ...
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2answers
57 views

Open Source solution to batch process shortest distance between points along road networks?

I have the locations geocoded (a fairly small dataset, ~200), but I haven't found a straightforward way to load these data into QGIS and perform network analysis between nodes. Any suggestions? ...
1
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1answer
34 views

Convert From Northing/Eastings to Latitude/Longitude with QGIS

How can I convert a file with the projection below (NAD83) to one with Latitude and Longitude? The import file is a SHP file and I would like to export back out a SHP file. +proj=tmerc +lat_0=0 ...
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0answers
26 views

Assigning Color Ramp using PyQGIS

According to the PyQGIS Cookbook, a color ramp can be assigned in the following way: rlayer.setColorShadingAlgorithm(QgsRasterLayer.ColorRampShader) lst = [ QgsColorRampShader.ColorRampItem(0, ...
0
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1answer
59 views

Creating Map from database

I'd like some general advice on creating dynamic maps. I have a bunch of geospatial points saved on SQL Server and PostgreSQL. People will enter new data into the databases from time to time. I want ...
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2answers
45 views

Contour of single feature on QGIS

I'm trying to extract one single contour line at given elevation from a DEM. Taking into account that I want only one contour and not all contours with the given elevation, is there a way to do it in ...
1
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1answer
17 views

Print with different settings of layer view?

Using QGIS is it possible to print on the same paper two windows with different settings of layer? I mean: window1: layer1 ON - layer2 OFF window2: layer1 OFF - layer2 ON
2
votes
2answers
54 views

Printing A3 format map

I have a question about printing A3 map from QGIS. I'm going to make A3 map of one country and nearby countries, digitalise borders etc. I want to save it to A3 format, but I have only A4 printer, ...
1
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1answer
30 views

How to load territorial maps on QGIS from web?

Is it possible to use QGIS like Google Earth? I need to draw simple shapes on territorial maps. I would like to do that without using multiple files for each part of the Earth. I use QGIS 1.8, but I ...
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0answers
28 views

Raster calculation with string in modeler

In my model I have one raster file and also a string input (factor for further calculation). I tried to use the grass r.mapcalculator where I can find the raster and also the string input. I tried to ...
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1answer
21 views

Problem by changing the order of Layers in QGis Layer Tree

I'm using QGis 2.4 on a virtual machine (Ubuntu 14.4 with XFCE). I'm connected to the VM via vncviewer, what works pretty well. But now I want to add some more layers to an existing QGis Project. ...
2
votes
2answers
71 views

Can't transform lines to polygons

I have a similar question to: How to join lines in QGIS for later using "lines to poly"? I have a line shapefile that I wish to transform into a polygon shapefile. After making some ...
1
vote
1answer
28 views

How do you extract the data behind a raster histogram

Bit of a newbie, so this may be a daft question. I have an .ecw picture - it is has no CRS, as it is a picture taken at ground level with an NIR camera. It was originally converted from a RAW image. ...
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0answers
43 views

Geometric functions in field calculator in QGIS

I had a look in the manual of QGIS and I also browsed the Internet to find some useful information about the geometric functions of the field calculator. I've found this post but I'm still confused. ...
1
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1answer
31 views

Pattern Effect in Pie Charts in QGIS?

I have more than 3 attributes to add to pie charts in QGIS, so I need a patterned fill e.g.dots, lines. Using a grey scale gives white, black and grey but using different shades of grey doesn't work ...
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0answers
35 views

How can I get a .asc file to load into QGIS?

I got some files from an ag plane that are in ASCII format. I can not seem to be able to get them to load into QGIS without the This is a link to the file I am trying to use. ...
2
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0answers
25 views

infer the altitude from a DTM & finally provide it to point / evincere la altitudine da un DTM & finalmente fornirla a dei punti

I would like to complete a point vector's table with Z data. I am not able to take Z coordinate from a dtm (downloaded from ...
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0answers
37 views

Generating Heat Maps with GeoHash

I have a long list of GeoHash codes for a certain geographic region. I'm using 6-character precision so for example if the area under study was Earl's Court in London, I would have a few six letter ...
1
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1answer
31 views

How to programmatically create nested layer groups?

Using PyQGIS via the QGIS 2.4.0 Python console and the editor, I can create parallel groups for storing some layers with: MyFirstGroup = iface.legendInterface().addGroup('Group No. 1') MySecondGroup ...
2
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0answers
18 views

QGIS small install package for use in low-bandwidth settings?

I'm a cartographer and data analyst with experience using ArcGIS and QGIS to format data and produce maps for a global public health contract. I am working with a group of QGIS learners from Africa ...
4
votes
2answers
87 views

How to enter a date into the attribute table?

This may be something simple stupid but in QGIS 2.4 I have created a date column. How do I enter the date in correctly. Every time I type a date in, in whatever format it does not move that entered ...
3
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1answer
61 views

Drawing isochrones on map?

I am a fourth year graduation student of the Amsterdam University of Applied Sciences. I am currently working on my final thesis for which I am doing research on the Amsterdam Airport catchment area. ...
15
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3answers
281 views

Zigzag Line Symbol in QGIS

I'm looking for a zigzag line symbol in QGIS. Is there perhaps an easy way to do this that I'm missing? I have tried creating a marker line using a simple triangle marker (^) and adjusting the size of ...
2
votes
1answer
99 views

How to measure distance between points based on elevation?

I need to be able to measure distances between points, however the distance need to be calculated in relations to elevation. The points are homes of storytellers from the 19th century and the places ...
1
vote
1answer
56 views

How to create a Processing script using the shortest path algorithm?

I'm currently using the Road Graph plugin to find the shortest path in a road network - however, I'd like to put this to a processing script (to be used in a model later) and the Road Graph Plugin has ...
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0answers
15 views

How to mosaic lots of TIF files [duplicate]

I have 550 piece of .Tif fil files. I need to mosaic them. I tried QGIS, ERDAS and ArcGIS but they crashed everytime. In Erdas Tif's stored only 4GB limit of size. Which solution can be useful for me ...
2
votes
1answer
42 views

Opening GeoTIFF (georeferenced in ArcGIS for Desktop) in QGIS?

I tried to open a georeferenced geotiff created in ArcGIS for Desktop in QGIS. I could open them but they are not in the right spots. These raster datasets contains .aux .rrd .tfwx .tif.aux.xml ...
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0answers
16 views

Is there a way to include code/language for offsets within the “script” at the CRS dialogue screen

I'm pretty new to QGIS and coming from being just good enough to be dangerous in Manifold GIS. I have some JPEG 2000 rasters that were exported from Manifold in UTM 18S, and then imported into QGIS, ...
2
votes
0answers
55 views

QGIS 2.4 NVIZ Solution

I am going to ask this question better: What happened with NVIZ? I do not know the exact version that nviz stopped working but it seems around version 2 of QGIS. There are two ways to get to nviz in ...
1
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1answer
69 views

SQLite instead of gdb

I use ArcGIS and Qgis and I want to have common protocol and format of my files. To use a separate file for each program is not the best way, I don’t want to make a mess of data. I would ask if SQLite ...
1
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1answer
28 views

Unable to add features in QGIS 2.4.0

QGIS beginner problem. I can no longer create features with "Add Feature" in QGIS. The info triangle message is "Transform error caught: forward transform of (0.000000, 0.000000) PROJ.4: ...
2
votes
0answers
45 views

How to get user and password of a PostGIS layer

I wonder if it is possible to get the user and password for a PostGIS database if they are stored in the PostGis connection information. I get the connection information at the moment from the ...
2
votes
2answers
42 views

QGIS layer tree API returns only groups and not layers

I am trying to use the QGIS python API to read out the groups and layers in a QGIS (2.4) project. Here is a code snippet from my script, which is run from a shell, not from the QGIS python console! ...
3
votes
2answers
45 views

OpenWind Zone of Visual Impact transparent pixels?

How do you make pixels which are not visible from a point be made transparent and the pixels which are visible opaque so that I can overlay the raster over a map to see clearly where you can and ...
2
votes
1answer
67 views

QGIS 2.4 dissolve doesnt work properly, why?

I am used to work with ArcGIS and now I started to explore QGIS more. I have problem with dissolve function. I have administrative borders and I would like to dissolve them into higher administrative ...
2
votes
1answer
34 views

QGIS 2.2.0 Valmiera

One to many joins Unable to export as WKT geometry I'm trying to perform a one-to-many join between a postcode dataset (shapefile) and a csv txt dataset of addresses. I have multiple addresses per ...
2
votes
1answer
93 views

Is there an equivalent of ArcGIS Hyperlink script editor in QGIS?

I am trying to find similar functionality in QGIS to ArcGIS Hyperlink script editor. In ArcGIS I can parse VBScript from a selected field in an attribute table. The script would execute on mouse ...
1
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2answers
37 views

How does QGIS Identify Features plugin work i.e. what is logic behind it?

I'm new to QGIS and python as well. I need attributes and their values of a selected vector layer, in the similar manner as Identify Feature works only difference is I don't wish to show them in a ...
2
votes
0answers
36 views

OpenLayers preview problem?

I just want display shapefile (.shp) that I have made in QGIS in openlayer geoserver. but There is a strange object that appears. I want to ask how to get rid of the strange object.
3
votes
2answers
27 views

QGIS ASCII Grid output problem

I have this .asc file of maximum temperature of a local place. This file is a result of vector to raster (GeoTIFF) conversion then GeoTIFF to ASCII grid conversion, both using QGIS. Here is a snippet ...
0
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0answers
35 views

Can QGIS generate a map that composed of several .shp maps?

I'm using QGIS-2.4.0 API to develop application. I need a map that composed of several vector layers. If only this, it can be done by merge in QGIS, but I need more for that: the map(or project?) I ...
1
vote
1answer
19 views

Change QGIS Processing (Sextante) default arguments for r.out.gdal

Lately I've been using r.grow through the QGIS Processing Toolbox on several rasters which represent the whole world with 500m grid spacing. It takes many minutes to save the output. The reason seems ...
2
votes
0answers
18 views

Path on network returning wrong results

I have created a shapefile of polylines that represent a path with multiple intersections. Then I have used the networkx python library to create a network. At the first the results were satisfactory. ...
3
votes
2answers
37 views

Digital Elevation Model and Shapefile not aligned in openWind

I have a digital elevation model and a shapefile containing point features for the location of wind turbines. These two layers appear to be aligned in QGIS but when I open them in openWind, they are ...
2
votes
1answer
50 views

Plotting Postal Codes from .csv Files in QGIS

I have Canadian postal code data that I would like to plot. This data is currently stored in a simple .csv file. At the moment the only other data I have is FSA data from Statistics Canada. Is ...
1
vote
1answer
33 views

create buffer to QGIS [duplicate]

I'm trying to create a buffer I'm using QGIS 2.4.0 layers and have street departments and rivers with coordinate system EPSG: 4326 - WGS 84 I need to create a buffer layer 500 meter rios This ...
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0answers
21 views

QGIS Server does not publish Oracle Spatial Layer

I want to publish a Oracle Spatial Layer which is defined in a QGIS Project with the QGIS Server as a WMS. The capabilities document of the QGIS Server does not include the layer description of the ...
2
votes
0answers
29 views

Command line tools to generate elevation profile from DEM + GPX/GeoJSON

I'm looking to generate elevation profiles from a number of GPX traces (which I also have GeoJSON conversions of). I have 20m resolution DEMs of the area, in GeoTIFF format. Ultimately I want to ...