Tagged Questions

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

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2answers
132 views

TatukGIS SQLite Spatial vs. Spatialite

I must apologize in advance, I'm just getting into GIS and trying to figure things out. I have an SQLite spatial database that I'm pretty sure was created in TatukGIS. I've tried to open it in QGIS ...
1
vote
1answer
88 views

Is there a way to access the GeoProcessing tools in QGIS, in code

Is there a way to access the GeoProcessing tools in QGIS, in code? I want to find the Difference between two layers and make a new shapefile with the result.It can be manually done by selecting ...
0
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2answers
52 views

How to join data in postgis tables to form layer with subset of attributes

In QGIS I am trying to join data from two postgis tables. I can not figure out how to do this at sql because add layer tools seem to allow one to select just one table to filter on. Instead I ...
1
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1answer
66 views

label vector line with multiple attributes in QGIS

I have a line with two 2 attributes. I would like to display both information along with the line in frequent interval, one info above the line and the other is below the line. I am working in QGIS ...
0
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0answers
21 views

Semi-Automated Classification Plugin ROI Creation Failure

I can't get the Region-growing to work when running the ROI creation module. What am I missing? Please see the "AttributeError" line halfway down: # An error has occured while executing Python ...
2
votes
3answers
177 views

convert a shapefile into graph with nodes and edges

Is there a way to convert a shapefile into graph with nodes and edges(except networkx). I'm using qgis and I want to convert a road vector layer into a graph, so that I can use it to apply shortest ...
1
vote
1answer
122 views

QGIS/PostGIS: Select Counties within Region via Spatial Query

I'm using GQIS 2.2 and PostGIS on Postgresql 9.3. I have 5 regions in the contiguous United States. Each region has states, and each state has counties. I would like to think that the data I'm given ...
0
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2answers
44 views

shapefile terminology for key-value pair

In an .osm file, there are <TAG ... /> elements like <way visible="true" id="-4409" timestamp="1970-01-01T00:00:00Z" version="1"> <nd ref="-21845"/> <tag k="fcc" ...
3
votes
0answers
66 views

Is there a “Disperse Markers” tool for QGIS?

I am using ArcGIS, but either I would like to use QGIS and maybe want to switch completely later. A have a point overlapping problem, as a result of geocoding of addresses. I have not found any ...
2
votes
1answer
131 views

Does not show shortest path in networkx (in QGIS)

I used the following commands (in qgis console) to get the shortest path with astar algorithm. But the result shows 'NetworkXNoPath' every time. Why was that? Please help me to find a solution to this ...
1
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0answers
37 views

Is is possible to run the QGIS python module server side?

I'm pretty new to programming but I want to use the QGIS python module on a server. Basically I am trying to create a JPEG map programatically on a server. I already have a python script to create ...
2
votes
1answer
286 views

QGIS says “osgeo [python-gdal]” isn't installed on Mac

I know similar questions have been asked (like this one) -- but I'm encountering a unique problem. I installed GDAL complete 1.11 from KyngChaos, but when I open QGIS, I get the following error ...
0
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1answer
165 views

Issue loading layer from OpenLayers plugin in QGIS

I installed the OpenLayers plugin in QGIS and tried to load one of the layers. Regardless of which layer I try to load, I am getting an error message. See example: Does anyone know how to resolve ...
0
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0answers
38 views

Problem zooming in on ECW files in QGIS

I opened a 490mb ecw image in QGIS on my mac (using the ecw 1.10.1 GDAL-ECW plug-in & 5.1.1. ERDAS Image Compression SDK read-only for desktop). The ecw is loaded in less than a second, but it ...
0
votes
1answer
361 views

Missing QGIS raster menu tools - '“osgeo [python-gdal]” module is missing'

I recently had to reinstall QGIS (version 2.2.0-9) and the raster menu is missing its tools. I understand that the GdalTools plugin must be installed and enabled. I have already installed the GDal ...
0
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2answers
104 views

Identifying clusters of points within a given distance

So I have a database of lats/longs representing incidents occurring on or near roadways. My goal is to identify the street block areas with the highest number of incidents in the database. I don't ...
0
votes
1answer
143 views

Why do I get these bands on my Height/Dem/Raster

I can't seem to get rid of them, and I've no idea (ok scrap that, I have a vauge idea) whats causing them. First an apology, yes this is quite a large pic apologies, but here goes: How to ...
0
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1answer
63 views

Issue clipping vector file with QGIS (geoprocessing tools)

I am trying to clip wind speed data (.shp format) to Canada's provincial boundaries (also .shp format). I am using the clip feature in vector > geoprocessing tools. For some reason the function always ...
2
votes
2answers
330 views

Qgis installation fails on Ubuntu 14.04 [closed]

I am having problems installing Qgis on Ubuntu 14.04 (Trusty). I tried several approaches: installing from the Ubuntu standard repos, installing from http://qgis.org/debian and installing from ...
0
votes
1answer
63 views

Searching closest region from Google Maps coordinates

Here is my problem. I'm mapping a region in google maps after that I'm saving the coordinates in PostGIS databse as geographic Polygon type. ST_GeographyFromText('SRID=4326;POLYGON((..))') The goal ...
0
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0answers
30 views

Rasterizing vector contour data: Python error message

would anyone know why qgis kicks up this error message (image attached) when using v.to.rast.attribute? the rasterise related to a contour set. i duplicated it twice to create 3 copies. the first ...
1
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2answers
77 views

Create Shapefile of all overlapping features from single Shapefile

I need to create a Shapefile out of another Spahefile that consists all overlaps of features within the initial Shapefile. I'm sure there is a simple solution using ArcMap or QGIS, but at the moment ...
0
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0answers
65 views

QGIS r.cost / r.drain and errors

I'm trying to find the optimal route of several archaeological sites with Qgis 2.2. I've a DEM and r.walk or r.viewshed executed successfully, but r.cost always fails creating the output, however ...
1
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0answers
69 views

Create a non spatial index on an attribute in QGIS before joining two layers

I’m using QGIS 2.0.1 on Windows 7. I’m trying to join a .dbf which contains no spatial data to a shape file containing spatial data. Ideally I’d like to create an attribute index on the join field in ...
0
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1answer
22 views

Road Graph Settings

I am unable to configure road graph setting. in "Plug in Menu" there is no road graph settings but it is already installed. Please tell me how to solve this problem.
0
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1answer
83 views

QGIS raster calculator manual or help

There is plenty unknown about how to use raster calculator, for example: how to write NODATA (Null) value in expression is it possible to use within (polygonLayerName) to clip result between shown ...
1
vote
3answers
423 views

How to get shapefile of river from OpenStreetMap?

I dont want to download whole map of an area. I just want rivers and other waterbodies present in an area in shapefiles so that I can use them in Qgis. I tried geofabrik but it is giving whole map and ...
1
vote
0answers
109 views

Can't see Postgis layers added to QGIS

I'm trying to transition from an old Postgres/Postgis database to a new one. I'm working in a fresh install of Win 7 64 bit. I installed Postgresql 9.3 32 bit, then installed PostGIS 2.1.3. I created ...
0
votes
1answer
65 views

How to add point attributes to containing polygon?

I have three layers in a QGIS project: layer 1 is a boundary layer of polygons each with and id I will call "p_id" layer 2 is a point layer each with an id called "p_id" layer 3 is a .csv layer ...
0
votes
0answers
48 views

Create GeoTIFF for a specific scale

I am working on creating several GeoTIFFs in QGIS. My workflow was to: 1) Export the PDF map at the desired scale (1:64m) 2) Design the map and export the TIFs from Photoshop (I've used several ...
1
vote
2answers
317 views

How to enable multithreaded processing in qgis 2.2

I have found multiple links that appear to say that this now exists in qgis 2.2, but it appears that it's only using one core to full capacity. This is running on Ubuntu 14.04 The current process is ...
2
votes
1answer
124 views

QGIS Python Scripting - Syntax definition

After playing around with the Model Builder and looking at the python scripts of what I make, I noticed some syntax which I can't find the definition anywhere. Here is a snippet of the python script ...
0
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0answers
43 views

Open Source .Net GIS software end-to-end

I need to provide a client with an end-to-end web-based GIS solution running on IIS. I will admit to not knowing much about the subject, other than having developed a Google Earth enabled version of ...
0
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0answers
69 views

How to connect two line ends in QGIS without resorting to other software?

I have two adjacent (ends meet to make one line) polylines in QGIS. I need to properly connect the two ends of the two sections. I've tried the obvious (and less obvious too) but QGIS won't forget ...
0
votes
0answers
55 views

change default font of labels in QGIS

I've just opened a feature request, but maybe someone knows a temporary solution. In QGIS 2.2 one can change the default font of the Print Composer (through the Menu Option -> Setttings). But I think ...
0
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1answer
51 views

style creation in QGIS

I want to create a line style in QGIS (model is attached here with), Any body can help me?, please help me.
0
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1answer
46 views

QGis export part of map (box with coordinates) as raster

I would like to export a map of Switzerland (as part of googlemaps) to use as a background for a graph, but I need to know exactly where each corner of the map corresponds to (wrt spatial ...
1
vote
2answers
121 views

User defined Coordinate Reference System (CRS) in QGIS is not located where expected?

I have received a shapefile with a user defined projection (i.e., +proj=krovak +lat_0=-32.923433 +lon_0=116.47485 +alpha=111.423433 +k=1.00004 +x_0=44328.529781 +y_0=1345943.211845 +ellps=GRS80 ...
1
vote
1answer
162 views

Opening *.pmf file using QGIS?

I have spatial data that has been put together with ArcGIS for Desktop and exported to me as a .pmf file. I'm spearheading a complete move from ArcGIS to QGIS and trying to make our old data still ...
0
votes
0answers
79 views

How to print a WMS map with chosen scale and WMS zoom level?

I am trying to print a WMS map in QGIS. If, while in the print composer, I chose a "25000" scale, the composer chooses a WMS layer that actually shows a 1:50000 map. To get down deep at the 1:25000 ...
1
vote
1answer
129 views

Spatial Join in QGIS 2.2

I am trying to spatially join point layers of some 12,000 women interviewed in Egypt to Egypt's polygon layers (administrative districts boundaries) using QGIS 2.2 and need some advice. I am a QGIS ...
0
votes
1answer
49 views

PyQGIS: How to send signal to call unsetMapTool()

I've created a map tool to add some functionality to adding point features in QGIS 2.0. I'd like to unset this map tool if editing has manually been terminated by user. I've attempted as shown below, ...
0
votes
1answer
46 views

Add attributes to an output shapefile schema (via meta)

I am trying to copy the schema of an existing shapefile and add to it in an output shapefile. Somehow I am not getting anywhere with this...though the docs seem very clear (and the download page : ...
0
votes
0answers
44 views

How to overlay polygons that are in the same layer

I need to INTERSECT many polygons that are in the same layer. Actually each polygons from my layer represent an area of influence from one specific bird species. Since I used to use ArcMap, I found ...
0
votes
0answers
53 views

PyQGIS: QgsMapTool to add point feature

I am having issues programmatically adding point features using QGIS 2.0. I am trying to add a point feature, select another layer's nearby feature, and open the feature form to enter attribute data ...
0
votes
1answer
62 views

QGIS convert polyline to fixed width polygon

I have a shp file of polylines for trails, and I need to convert them all to be polygons that are 8 ft wide (4 ft from the center of each side of the polyline). I tried a following a few other posts ...
2
votes
0answers
78 views

How to get QGIS to play with pandas (Windows)?

has anybody been successful getting pandas to work with QGIS's Python installation, on Windows? I've used the OSGeo4W installer to install QGIS2.2, which comes with Python 2.7 and Numpy 1.5.1. Any ...
1
vote
1answer
66 views

Error: Algorithm not found

I wrote the following code to start using QGIS APIs. in a very short script seen below, the "Error: Algorithm not found" is thrown and "print processing.alglist()" is showing none. Any idea why this ...
2
votes
0answers
30 views

QGIS : launch Atlas composer generation from command line

I am using QGIS 2.2 and have configured a composer with atlas generation. I would like to launch this atlas generation every day. The idea is to write a batch and launch it with a cron. Is it ...
0
votes
0answers
30 views

Disable option in QGIS which picks 4th band as alpha band

Is there a way to disable that function? As somebody who works with 4 band orthoimagery on a daily basis, it is annoying to go to the transparency options every time I load an image to disable the ...