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

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2 views

Make ldouble list in qgis

I want to create a table whith two drop-down lists. If I select somthing from first drop-down list in the second will change attributes that I can choos. For example, if in the firstlist I pick a ...
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0answers
4 views

Create Random Points with a specific table

That's my question. I have 3 tables in a Database: The first table is joined with another table (TABLE 3) where are stored 4 or more pairs of coordinates (so for one record of TABLE 1 there are more ...
1
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1answer
17 views

Why does one polygon disappear when merging in edit mode?

I want to merge some polygons into one using the merge tool. But when doing so, one of the polygons just disappears (see screenshot 2). Why does this happen? When I use the simplify tool before, it ...
1
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1answer
6 views

QGIS georeferencer - GCP projection problem

In short, the problem is that when Geoereferencer is reopened with a previously edited raster, all the previously saved control points have moved off the image to a location thousands of kilometres ...
4
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3answers
2k views

Using CityGML data with ArcGIS Desktop or QGIS?

I'm looking for advice on how best to use the CityGML data-structure and GIS (preferably ArcGIS/QGIS). I've read through their website and wiki and saw a list of software here that can be used to view ...
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0answers
8 views

Labels with buffers creates bloated PDF file in Composer

I know this question has appeared before, but the earlier questions appear to be linked to the old labeling engine. I'm running qgis 2.0, which I thought uses the new-generation labeling engine. In my ...
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0answers
17 views

What QGIS line styles work best with Garmin maps?

I am using QGIS to create some maps to load on to a GPS using the plugin. When I display the maps on the GPS the lines are very faint and I can not distinguish colours and some colours vanish ...
0
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1answer
12 views

How to coalesce frames with mencoder in QGIS Time Manager plugin? [on hold]

I need some guidance putting the exported frames together from the QGIS Time Manager plugin. I saw your line about mencoder, so I downloaded it along with mplayer, but I'm not sure how to use them. ...
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0answers
21 views

Connecting points with lines [on hold]

I have the centre of some buildings (polygons) and the road network of the area. The road network will be used as a pipe network as well. So I want to connect each building to the main transmission ...
3
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0answers
28 views

How to connect centroids of lines sharing the same intersection in QGIS?

I'm looking for a big help to accomplish the following task: I have this street network of the center of Turin (IT), composed by lines representing streets, and black points representing ...
1
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0answers
36 views

Along a line create profile/cross-section lines then extract elevation points from them

I know that maybe this question has got an answer, but I need to extract elevation data from a line of a defined length (p.e. 300 meters). Also I want the software (QGIS or ArcGIS) to draw this lines ...
1
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1answer
9 views

QGIS 2.6: CRS was undefined defaulting to WGS84

I'm working in a UTM projection and bringing in dxf layers from a different program. The dxf files are all in the correct UTM coordinates already, but when I bring them in I need to change the CRS to ...
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0answers
9 views

QGIS vector line layer doesnt accept cyrillic letters [on hold]

In QGIS 2.6 vector line layer doesnt accept cyrillic letters, how can i fix this? For polygon it it works fine but for line and point it only gives me set of question marks - ?????
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1answer
27 views

Building heights above DEM through field calculator

I have a series of building polygons which I would like to convert to a raster illustrating their height. I have the building heights but not their elevation above sea level datum. I have the ...
0
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1answer
122 views

Using gdal merge correctly?

Currently trying to use gdal_merge within qgis to stack three raster bands, the command it's showing is like this: gdal_merge.bat -separate -of GTiff -o out.tif "LC80190302014126LGN00_B4.TIF" ...
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0answers
10 views

QGIS 2.4.0 CRS reprojection creates empty files and goes generally nuts

I consider myself an intermediate GIS user but keep running in a problem with the newest QGIS version I cannot fix and wonder if it may be a bug or if I am just too stupid. The problem mostly centers ...
2
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0answers
15 views

How to load all items from a template with pyQGIS in QGIS 2.6

Since QGIS 2.6, the LoadFromTemplate method seems not work any more (or works differently?) This is my code to add items in my composer from a template : self.composition = ...
0
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1answer
25 views

QGIS abbreviate labels with dictionary

I'm trying to use qgis "expression dialog" for labeling a layer. What I'm looking for is an expression that permits to apply some abbreviation rules on the layer. For now i'm using this CASE WHEN ...
0
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1answer
267 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 ...
0
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1answer
12 views

Many ELSE statement in Expression in QGIS (2.6) [duplicate]

is it possible to have more than one ELSE in the CASE WHEN statement in the Expression builder in QGIS? For example: CASE WHEN "population" > 5000 THEN 'big' ELIF WHEN "population" > 1500 THEN ...
7
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4answers
2k views

Elevation profile 10 km each side of a line

How can I get an elevation profile for a band of terrain? The highest elevation within 10 km (on each side of the defined line) should be taken into account. I hope my question is clear. Thank you ...
0
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0answers
61 views

OpenLayers and GeoJSON

Recently I started learning Openlayers 2x and I've been struggling for a while now with a GeoJSON and it's projections. So, here is the deal; I successfully added wms layers from ( ...
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0answers
49 views
+100

QGIS crash when I try print geometry

I do (It`s work): from osgeo import ogr inputds = ogr.Open(r'c:\temp.shp') inputlyr = inputds .GetLayer() for i,feature in enumerate(inputlyr): print i, feature.GetGeometryRef() Output: 0 ...
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1answer
20 views

Changing mouse wheel zoom settings in QGIS?

I'm having a problem with the mouse wheel zoom setting on my macbook trackpad. The zoom occurs far too quickly for any level of precision. I noted this comment in the dev log: 2004-08-14 [gsherman] ...
0
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1answer
128 views

Change the value of an attribute using QgsFeature object

I would like to update one attribute of a feature. However, I don't know to update it using the feature object. I have to use data provider to update it. layers = ...
0
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1answer
14 views

QGIS - use atlas attribute with 'Like' command

Does anyone know how to use the new get Attribute function in conjunction with the "Like" command? I have a table with an Attribute "Sub_Region" and want to show the features that match the atlas ...
2
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2answers
46 views

QGIS calculates main soil type of polygons from another polygon layer

I've been working with qgis for a while but somehow I never fiured this out, so I thought it's time to ask. I have 2 shapefiles. a polygon layer from nearby fields (SHAPE1 (the red outlines)) a ...
2
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0answers
37 views

Create “mean” line from multiple lines using QGIS

I have multiple lines features (also have them in multipoints...) representing similar path (mountain trails, in this case) with various GPS precision, resulting in many lines close to each other, but ...
3
votes
1answer
74 views

“Singleparts to multipart” vs. “Dissolve”

It seems to me that the vector tools "Singleparts to multipart" and "Dissolve" do the same things. Can someone confirm this, please? Or do I overlook something?
1
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2answers
43 views

How to merge shapefiles with the same attributes?

Let's say, I have two shapefiles, a.shp and b.shp, containing point features with the follwing attribute tables: a - id att1 att2 ----------------- 1 1 1 2 2 2 b - id att1 ...
3
votes
1answer
125 views

Memory Vector Layer Corrupted?

I was working with a large data set that had data for roads, rivers, railways, etc. all together so I decided to break the different data out so I could label it differently on the map and check each ...
0
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1answer
24 views

How to get image pop ups in QGIS?

I have a map of an area and georeferenced photos. I need to be able to bring the pictures as points and then be able to click at a certain point and an image pop up.
1
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1answer
33 views

SVG from QGIS to Illustrator CC gets wrong stroke widths

When I export SVG files from QGIS using the Print composer the stroke widths become a lot wider when importing into Adobe Illustrator. It seems like the stroke width in the SVG translates differently ...
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0answers
11 views

ArcGIS Online : 'Unable to import this shapefile (a is undefined)'

After saving a shp file from QGIS I get this error adding the shp to ArcGIS Online: 'Unable to import this shapefile (a is undefined)' I tried saving in different projections (WGS1984 (EPSG:4326), ...
2
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1answer
20 views

How to convert a RGB tiff into pseudocolor with GDAL etc?

In QGIS I have made a singleband pseudocolor image out of one of the bands from a RGB GeoTiff. I choose one band and then make a linear color interpolation (see attached image). I now want to do ...
1
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1answer
34 views

Adding items to DEM in QGIS

Working with QGIS and Grass I would like to produce a ZTV. I have the bare land DEM happily ready to go but would like to add buildings and woodland to the calculation. Can anyone please point me in ...
1
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0answers
20 views

In qgis using python, how can I get multiple pixels from a raster based on a vector point file

I just started working with qgis, and for the life of me I cannot figure out how to solve this problem: I have several points of interest, these are stored in a shape file (just simple points). I ...
0
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0answers
7 views

saga:slopeaspect curvature

I'm using windows 7 on 64 bit and using Qgis 2.6.0.I'm trying to process some Tifs from the console using the processing toolbox and saga:slopeaspectcurvature. This is pretty much how my code looks ...
2
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0answers
24 views

“Georeferencing” lidar data to accurate survey

Often I obtain LIDAR data for concept studies and conventional survey (in dxf format) over a small portion of this. The LIDAR typically covers the broader area and is used for broader studies, ...
0
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2answers
16 views

Remove sections, defined by a line or polygon, from a raster in QGIS

(QGIS 2.6.0 on Windows.) I have created a raster layer of heights using the TIN interpolate function. I also have another raster layer with more accurate information on the height of particular areas ...
2
votes
3answers
295 views

Draw line between points from multiple datasets

I have 2 point datasets and want a tool or script to draw a line between all points in one dataset to all the points in the 2nd dataset. Is it possible? I have tried ESRI "Point Distance" and ...
0
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2answers
54 views

Non-standard WMS parameters not sent in GetMap requests via QGIS?

I am coding a python plugin to QGIS that connects to the UK National Biodiversity Network (NBN) Web Mapping Service (WMS). In general, I don't have any problems doing this with the QgsRasterLayer API ...
0
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0answers
13 views

How many Print Composers in a project before its too slow

We are using Print Composer in QGIS 2.6 to print map insets at specific locations, these have all been created and saved in the project. The project now takes a long time to just open, has anyone ...
0
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1answer
78 views

How to use shapefile in QGIS on Debian?

I am extremely new to GIS and I just received a shapefile, as a zip file that includes the following files: filename.SHX filename.SHP filename.prj filename.dbf filename.cpg but I am not sure how I ...
8
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1answer
2k views

Grid and Graticule in QGIS Print Composer

Is there any other option to display DMS grid and graticule in QGIS Print Composer, since there is no plugins available yet?
0
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0answers
38 views

Multiple Labels from attribute column in QGIS

I was wondering if there is a way to have multiple labels from a joined attribute table in QGIS. I have two tables, a polygon table, and a table with words (codes). The codes table can be joined by a ...
0
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0answers
8 views

mysql data automatically updates

Is my sql data automatically updated in qgis? We have connected the mysql with qgis but data is not updated automatically. Is there any other way to connect the datasource with qgis?
0
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1answer
19 views

QGIS Print Composer - SVG output displays objects outside the frame

On Windows 7. QGIS 2.6.0 from OSGEO network installer 64bit (and checked with latest dev version) I am preparing a print composer map displaying only vector data (shp). Data in the map canvas and the ...
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2answers
30 views

What are QGIS Arcpy Equivalent Functions for MakeFeatureLayer and SelectLayerByLocation?

I have a script that I had created using ModelBuilder, but our field personnel use QGIS 2.0. Below is a snippet of the code. I am wanting to know if there is an equivalent using pyqgis so that I can ...
0
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1answer
151 views

How to solve sqlite_rtree_geometry_callback error?

I have just installed qgis 1.8 and it show error message the procedure entry point sqlite3_rtree_geometry_callback could not be located in the dynamic link library sqlite3.dll How to fix ...