Tagged Questions

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

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1
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2answers
49 views

QGIS: Categorized styling - by multiple columns

I´ve got some polygons that I want to colourize by multiple columns. Can this be done or will I have to edit the attributes? Some polygons only have data-attributes in 1 one column, where as other ...
2
votes
1answer
26 views

multi-line attributes in composer

I have a multi-line text attribute in one of my layers, but when I try to display the data using the 'add table' function in Composer, it just gives the text a single line, not enough room to fit. ...
2
votes
4answers
181 views

How to create a new Shapefile with the same attributes as an existing one?

It is quite a frequent occurrence that I want the data I'm about to add to a new shapefile, to have all the same attribute fields as one I created in a previous project. For example, I might have ...
1
vote
2answers
46 views

Move coordinates using QGIS

With me I have a csv file. Am using qgis 1.8.5. I added delimited layer to a map shapefile in qgis. I noticed that some cooridates fell out of the boundaries of the .shp file. I selected the ...
0
votes
0answers
34 views

Free ebooks of QGIS [duplicate]

I am new to QGIS and python. Can any one tell me, where I can find QGIS and Pyqgis ebooks for free.
1
vote
1answer
52 views

Could not open/read USGS raster file

I could not open/read the following .img file. The document below says it is a raster file. http://edc2.usgs.gov/1KM/land_sea_mask.php I tried to open it using many ways such as Q-Gis software, and ...
10
votes
2answers
148 views

How can I parallelise embarrassingly parallel GIS operations in QGIS python?

A common requirement in GIS is to apply a processing tool to a number of files or apply a process for a number of features in one file to another file. Much of these operations are embarrassingly ...
1
vote
0answers
25 views

QGIS Upslope/Downstream Areas

I am trying to locate areas upstream and downstream of a point of interest in QGIS in order to determine possible areas of origin upstream and areas of impact downstream. I have used a DEM to create ...
0
votes
0answers
26 views

Syntax Error in qgsapplication file

I am trying to test an QGIS application code example. However, when I try to compile it, it is reporting errors in qgsapplication.h which is coming with the source code of QGIS. I am using QTCreator ...
2
votes
1answer
17 views

qgis-mapserver: GetCapabilities returns no layer

My problem is imilar to this thread I've installed qgis 2.4 and qgis server 2.4 on fedora. I created a simple project containing a vector layer (shapfiles) GetCapabilities request works but there ...
6
votes
2answers
104 views

How do I convert a tweet into a point in QGIS?

I've been doing some research on using R to datamine twitter, but I haven't really found an answer or a decent tutorial for my question. I'm interested in pulling tweets from twitter with a certain ...
0
votes
0answers
15 views

ArcGIS 10: How to mask a raster by using extract by mask tool If the feature mask is larger than the raster area?

I have a problem to mask the the raster which has values ranges -0.73106217384338 - 0.94593381881714. These values have been derived by using equatin (B3-B4)/(B3+B4) from Landsat band 3 and band 4 ...
2
votes
1answer
41 views

How to set default font in QGIS?

Is it possible to modify the default fonts to be used from "MS Shell Dlg 2" to another? If yes, where do I have to set it?
1
vote
0answers
11 views

How to get value and store it in a variable from a line edit or text edit in pyQT?

How to get value and store it in a variable (in main python plugin) from a line edit or text edit box that were created in QT designer ?
3
votes
1answer
64 views

How to make transparent the background of a WMS layer in Leaflet

I have inserted the following layer from a geoserver in the following Leaflet map : var nexrad = new L.TileLayer.WMS("URL", { layers: 'Wrecks:WrecksGreaterNorthSea', format: 'image/png', ...
3
votes
1answer
50 views

One vector data layer with different styles in QGIS

I have one layer of vector data that I would like to show in two different styles. Is there a way of accomplishing this in QGIS? I've solved it now by duplicating the the vector layer and add ...
1
vote
0answers
15 views

Error with qgis2threejs plug-in

I am currently endeavouring to use qgis2threejs to create a 3D visual using DSM and orthomosaic data captured using my unmanned aircraft system (UAS). Originally the plug-in seemed to work perfectly, ...
2
votes
1answer
14 views

How to obtain geographic points with a cdv file

I have a xlsx file with a column called CoordX and another with CoordY, I save the file in CSV format (semi-colon) and use the delimited text plugin and follow all the information in the text box. ...
1
vote
2answers
89 views

How to draw polygons in shapefiles

I've hit a snag and realize this is probably a very simple and basic question, but how do I draw a polygon in a shapefile that I've created from joined points of 2 .csv files? Which specific tool do I ...
2
votes
1answer
22 views

QGIS Forms - How Do I Display a Read-Only Value?

Older versions of QGIS had an "Immutable" option for form fields to make it obvious that data was read-only. How do I display values in the current version and make it obvious that they are ...
1
vote
2answers
58 views

QGIS's raster calculator— running as a batch process?

I have a series of raster files (150 or so) that I need to multiply by a baseline raster. Unfortunately, the series of rasters have a different cell size (30mx30m aka .00027777778 degrees x ...
0
votes
0answers
17 views

Extracted Contours from DEM translated in QGIS for certain intervals

I created a DEM from several point files in QGIS. Both of these line up well with the remaining data in my file (ie cadaster, aerial imagery, etc). I wanted to generate 2m contours from the DEM ...
1
vote
1answer
34 views

How to load a *.qgs file in a C++ QGIS standalone app?

I'm using QGIS-2.4.0 API to develop a standalone app by C++. I saved a test.qgs file in QGIS Desktop software, in the project, there was one layer and it was visible. Then I loaded the test.qgs ...
1
vote
1answer
30 views

Repetitive behavior in QGIS plugin in connection between Cancel button and pushButton

I'm trying to build a QGIS plugin where I need to ask for a file name using a pushButton connected with a QFileDialog object. I've built a simple plugin using the QGIS plugin builder (putting the text ...
0
votes
2answers
24 views

QGIS 2.4 crashes when symbolizing QgsComposerShape in Python with ScriptRunner

I'm attempting to use ScriptRunner to output a jpeg of a red rectangle using QGIS Composer to understand the QgsComposerShape. Everything works except QGIS crashes when the symbol is applied. The ...
3
votes
1answer
55 views

Is there a public repository of common formating styles for QGIS? Specifically for Tiger data?

I have downloaded the Tiger data for a map I'm working on and wonder if there is somewhere I can download the common formatting styles for these shapes so I don't have to reinvent the wheel. For ...
1
vote
0answers
51 views

How to convert length in Decimal degrees to meters programmatically?

I'm new to qgis and I want to find the length of some roads in a map. So I used the following code, from shapely.wkb import loads def getLength(): layer = ...
1
vote
0answers
13 views

Add WMS in QGIS gives an error with Map request failed [error:Host http not found url:http://http//

I got an URL from a friend who is working with Oracle MapBuilder. http://[IP]:11188/mapviewer/wms I tried to get the service via ArcMap and it was working. Then I tried my beloved QGIS and there is ...
2
votes
1answer
23 views

Meaning of r.viewshed output numbers in QGIS?

I have completed a r.viewshed analysis of a point in GRASS7. I have imported the arising Geotiff into QGIS and when viewing the layer in the layer window (after expanding the +) I am presented with a ...
3
votes
1answer
92 views

QGIS Calculate flow length path

I am trying to replicate my Erosion model in ArcGIS for Desktop to QGIS 2.4. I try to calculate in QGIS the upstream distance along the flow path for my agricultural field. I do the equivalent in ...
1
vote
1answer
17 views

Console application in .NET incorporating QGIS tools

I am working on a project where I want to build a standalone application in .NET using QGIS tools. Is there any option like the ArcObjects SDK for .NET? Please help me on this.
2
votes
1answer
43 views

QGIS Topology Checker select errors

I have used the Topology Checker plugin in QGIS to create rules to identify errors in my layer. For example, I have used it to search for all overlapping polygons. This plugin is great for finding ...
0
votes
0answers
24 views

how to add different data frames in QGIS? [duplicate]

![enter image description here][1]how can i add different data frames in QGIS and show all data frames in single map like we add different data frames in ARCGIS and in single map we show these data ...
2
votes
1answer
73 views

How to Make an Outside Buffer in QGIS?

I have a layer of street segments that are within a given distance of a fire station. Now I want to make a border around these street segments. If I use Buffer, it puts a buffer around each segment. ...
3
votes
1answer
65 views

Discover multipart features in a layer in QGIS

I am trying to identify multipart features using QGIS version is 1.8.0. I've tried: look at the attributes table select a random feature and check in the canvas if there are multiple geometries ...
1
vote
0answers
18 views

QGIS 2.4.0 doesn't support multiple types of geometry in GML file

I'm testing GML 3.2.1 data according to INSPIRE Data specification (version 3.0). Data for theme Cadastral Parcels shall have both polygon geometry and definition point. When I download data from my ...
1
vote
1answer
48 views

QGIS - Identify overlapping polygons in single layer

I have a shapefile of buffered points in QGIS. I need to display all buffer polygons in this layer which overlap. I have experimented with the intersect tool, but this only seems to work if I am ...
4
votes
4answers
245 views

What are good colour schemes for large density flow maps?

I came across nice QGIS tutorial for mapping flows. In contrast to Alasdair, I have zero talent in colour choice. Can anybody recommend some good starting points for nice colour schemes (I'd be ...
0
votes
1answer
15 views

Geoprocessing tool Difference from the Terminal?

I have used QGIS Geoprocessing tool Difference to cut polylines (SHP) into to smaller pieces using a polygon (SHP). This works very good in QGIS. Now, to speed up the process, I'd like to be able to ...
0
votes
1answer
27 views

QGIS 2.4: How to get Atlas to print all features not just the one visible in preview

I have a number of "zones" described by polygons that I use to produce a set of larger scale maps that I used to export into a pdf. This has stopped working (when I moved to 2.4 ??) and now I ...
0
votes
0answers
9 views

Error: Cutline feature without a geometry. > Raster Type

I've got an "Error: Cutline feature without a geometry" on QGIS 2.4.0 Chugiak. I have 2 samples (A raster type and a vector type), they have the same coordinates (EPSG:4253 - Luzon 1911) Then I tried ...
2
votes
1answer
56 views

Ideal file format for QGIS that allows mixed geometry types?

I have a spreadsheet for an archaeological project that is hosted on Google docs. This allows multiple contributors to edit and update the table as revisions and field data comes in. The table is not ...
2
votes
1answer
36 views

How can I properly clip a shape file to get the section I want using QGIS?

I've tried the other "how to clip" instructions here, but consistently get an empty shapefile from the clip. QGIS Version: 2.4.0-Chugiak OS: MacOS 10.10 Input File: San Diego (South Map) 1999 Topo ...
0
votes
2answers
63 views

NDVI derived from Landsat band 3 and band 4 using QGIS raster calculator shows the different range when opening in the ArcGIS

I have calculated Normalized difference vegetation indices from landsat 5 band 3 and band 4 that have 0-0.38 minimum and maximum ranges respectively. But whenever I open the same NDVI.tiff file in ...
2
votes
0answers
45 views

Iterating between two layers using QGIS python

I will try and explain my situation as clearly as possible. I just created my first plugin that is being used to analyze between various layers and give back quantities to the user. Most of it is ...
1
vote
1answer
23 views

Another Way to Join a New Column to a DBF if OpenOffice is Giving a “Longer Than the Number of Digits Allowed” Error?

When I need to add a data column to a DBF, I always download the shapefile, open the DBF with OpenOffice for Mac, us a VLOOKUP( ) to add my data to a new column, re-save the file as a DBF, then open ...
1
vote
0answers
30 views

Does QGIS work with Anaconda?

I am trying to get QGIS to work with the Anaconda distribution of Python but I do not know how to get this to work. In one of the answers it was mentioned that QGIS does not work with Anaconda and I ...
2
votes
0answers
44 views

How complete are the Fusion tools in QGIS?

How complete are the Fusion tools in QGIS? I have them installed and (vaguely) working, but there are only about ten of them. Is the idea of having just a few tools available, that one can use ...
2
votes
1answer
38 views

How to find length of a discontinued line feature

I wanted to find the length of features in a road layer. So I go through each feature in the layer and used, line = feature.geometry().asPolyline() to find the points which particular feature is ...
2
votes
1answer
38 views

How to use qgis coordinate transformation in user code

I am now working with coordinate transformations between different CRSs, e.g. latlong to UTM. After comparisons, I found out that the coordinate capture plugin in QGIS is quite accurate for the ...