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

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17 views

Raster import problem

I have raster images (orthos) and feature layers in a GIS program (Global Mapper). When I import these files with the same CRS into QGIS they are literally 9000 miles apart and I cannot figure out ...
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0answers
14 views

How to update the items of qCombox in custom form?

For my project I use a custom form with multiple value relation comboboxes. This works quite fine and I can access the widgets via my script. Init the two comboboxes which are correctly filled ...
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1answer
20 views

Displaying WMS Attribute Data in Lizmap

I have successfully built a Web server using ubuntu 14.04, Qgis 2.6, with the plug-in lizmap as a local server. I have several polygons being displayed and some WMS raster's from NOAA's WMS. I know ...
3
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1answer
63 views

Reprojecting between NAD27 and WGS 84 part III

I am trying to perform a reprojection for data with datum Nad27 to WGS84 datum. According to AndreJ in some previous questions in Stackexchange (CRS reprojection for instance) QGIS uses internally by ...
3
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1answer
78 views

How to use QGIS field calculator in python?

I would like to use QGIS Field Calculator in Python to update the existing column based on certain conditions? How can I do this?
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0answers
28 views

How to exit the QDialogBox button in qgis using python programming

I have created a dialog box with ok and cancel buttons.But i want one more exit button where it has to exit the QdialogBox. When i am using exit()it is exiting the complete qgis but i want to exit ...
1
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1answer
54 views

OTB Pansharpening Error

When I try to use the OTB pansharpening tool inside the processing tool box I always get this message: "Adapter for adaptPansharpening-bayes not found". I guess it's an issue withe the configuration. ...
2
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1answer
33 views

QGIS: How to merge single polygons to multi part polygons by maximum distances?

I have a polygon layer with a land-use class and ID for every polygon. How can I merge polygons (into multi part polygon) which do not adjoin, but are not further than x meters apart from each other. ...
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1answer
29 views

QGIS: raster import “nan”

I've been importing raster files in ZMAP format using QGIS 2.4 and 2.6. Some of the files work fine but other files for some reason import a black image with nan as a default black and white value. ...
2
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0answers
23 views

Creating QGIS multi-layer Topo Map of Lorraine Region of France?

I have a project I'm working on where I need a QGIS multi-layer Topo Map go the Lorraine Region of France between Metz and Nancy as a starting point, but I don't know where to start. What I need is a ...
1
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1answer
21 views

Automatically select small polygons contained within currently selected large polygons - QGIS

I am using QGIS (2.4.0) and I am trying to identify regions in Australia that are close to working mines. For this purpose I have 2 layers: Layer 1 - 535 polygons defining the various regions across ...
2
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1answer
43 views

Problem or ERROR in converting from raster to vector!

I wonder if anyone could help me out, i am kind of a beginner at QGIS. I´ve built a DEM for a project that i am developing than i´ve made the slope raster with the terrain analysis,it seemed that ...
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2answers
45 views

way/tool to automatically generate polygons on map knowing polygon width and height and spacing

I need to create a large number of polygons (say 1000) on a georeferenced mosaic (from aerial photographies). I know polygons' height and width, and I know the spacing between them. I can also provide ...
2
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0answers
39 views

Finding the slope of a polyline in QGIS 2.2 Valmiera

I am trying to find the average slope of a water course. I've drawn in the water course as a polyline over a large number of contour lines (the water course is long with a very large catchment area). ...
2
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3answers
50 views

Need to extract OSM data for my area from 2 neighbor countries

I need to prepare offline background data for my area of interest which is located around border between Czech Republic and Germany. I need to convert the OSM data to spatialite and then to use in ...
2
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2answers
72 views

CRS reprojection

I am trying to change the CRS of one shapefile that is originally in NAD27 to WGS84 in Qgis 2.6. When I proceed to make the change, I still continue to see the file in UTM coordinates... I've tried to ...
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1answer
20 views

problem changing CRS of a shapefile [duplicate]

I am trying to change the CRS of one shapefile that is originally in NAD27 to WGS84. When I proceed to make the change, I still continue to see the file in UTM coordinates... I've tried to save the ...
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1answer
37 views

Displaying polylines in different color / Color gradient

Though i am using QGIS, yet I am not confined by tool (can use an entirely different tool or a plugin for QGIS) usage.. Only aim is to get the following: I am reading various shapefiles in QGIS and I ...
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5answers
96 views

Selectively removing whitespace from a string with SQL

I have two columns of adresses that I need to join. Column 1 has the adresses formatted as "Some Street 12 A" while column 2 has them formatted as "Some Street 12A." Ie. the last whitespace between ...
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0answers
24 views

How to get the last edited feature id using python

After merging the two features in the polygon the feature id will be changed for the merged feature after committing the changes. So how do i get the feature id of the merged feature or the last ...
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0answers
18 views

QGIS GPS Information Menu Automatically Add Points

We are using a Surface Pro 3 with Windows 8.1 64bit, Bluetooth GPS, and QGIS (2.4 standalone download). We have opened a new QGIS project and are able to connect to the GPS unit within the GPS ...
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2answers
129 views

QGIS project with PostGIS layers freezes irregularly for minutes

I'm using about 30 more or less complex PostGIS layer in my QGIS project. Some of them are PlanetOSM layer generated with osm2pgsql. The Project loads fast (ca 5 sec). The canvas update by moving or ...
2
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1answer
53 views

Is it possible to subdivide scale bar segments in QGIS?

How can I subdivide the scale bar segments in smaller subsegments? I want to style my scale bar like this To make the question clear I edited the posting.
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1answer
79 views

shapefile for mumbai area or section wise

please don't kill me if this question is listed anywhere else, i really searched high and low to find answer to this question. i am working on a project in which i need to plot data on Mumbai city ...
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0answers
26 views

QGIS 2.4.0 seems to have issues with “Select By Location” for complex polygons. Are there alternatives?

I am attempting to use the "select by location" tool to select polygons from one layer that overlap with certain polygons in a different layer. Unfortunately this is causing QGIS to freeze. Doing a ...
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2answers
50 views

Highlighting features in qgis2leaf export

I have exported a QGIS map to Leaflet using the qgis2leaf plugin. I am looking for some assistance as to how to highlight features (polylines) when the mouse hovers over it. I just want the polyline ...
2
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1answer
26 views

Spatial join by categories in QGIS

I am using QGIS 2.4.0 and I have a vector layer which contains a remoteness indicator which is broken up into 5 categories. I would like to turn this into a layer that has these 5 categories collapsed ...
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1answer
31 views

PyQGIS export to JSON: writeAsVectorFormat and precision

In my QGIS plugin qgis2leaf I am exporting all layers as JSON into a JSON directory. Therefore I would like to enable the user to define the precision in the GUI. The normal "save as" dialogue in QGIS ...
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1answer
23 views

How to switch rule-based styles in loop?

I'm a working on a QGIS script that could activate/deactivate rule-based styles of the vector layer in a loop (one active layer per iteration). On the every iteration this scenario should: Activate ...
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0answers
26 views

How to open a second window in QGIS plugin from a button inside the main window

If I already created a qgis plugin, and i need to create a button inside that plugin that opens a new window, how is that possible? Qt creator won't add a slot unless there are a header file. I looked ...
2
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0answers
24 views

What does the Join button in the categorized style tab do?

I'm just studing gis, and I use QGIS. I have found in the layer properties some JOIN and don't understand how can I use It? Maybe someone can help me to undersan it, thank's!
1
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1answer
70 views

Why is the QGIS map composer grid showing unreasonable lat/lon?

I need to print a map with coordinates in the format of Degree, Minute and second. CRS is set to WGS 84 (EPSG 3857) for both layers and on the project properties it is set to enable transformation on ...
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0answers
16 views

Make ldouble list in QGIS

I want to create a table with two drop-down lists. If I select something from first drop-down list in the second will change attributes that I can choose. For example, if in the first list I pick a ...
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0answers
19 views

Create Random Points with a specific table using QGIS?

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 correspondences of ...
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2answers
31 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 ...
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0answers
23 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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1answer
37 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 ...
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1answer
45 views

Is there a way to change the QGIS default CRS?

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 ...
1
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1answer
18 views

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

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. ...
1
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1answer
22 views

QGIS vector line layer doesnt accept cyrillic letters

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 - ?????
1
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1answer
38 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 ...
2
votes
0answers
64 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
42 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
33 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 = ...
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0answers
33 views

Connecting points with lines [closed]

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
votes
1answer
45 views

How to make QGIS abbreviate labels with a 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 ...
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1answer
25 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 ...
2
votes
1answer
31 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] ...
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1answer
18 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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0answers
47 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 ...