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

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22 views

Is it possible to export layers scale-based visibility to a webmap?

Is it possible to make or convert a QGIS map into an interactive webpage map? For example, I have layers that appear at certain zoom levels, is there a way to have that interaction on the map for ...
-1
votes
1answer
40 views

QGIS2Leaf help when trying to export

So when I try to export to leaflet I get this Error and I dont know how to fix it....I went in to QGIS2LEAF export and imorted all my layers and selected OSM basemap and clicked Full screen, selected ...
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0answers
9 views

Creating random points using QGIS?

Has anyone else had any issues using the random points tool in QGIS? When I try using it I'm selecting the option to use a value input field. The tool starts but then freezes once it gets to the 10% ...
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0answers
7 views

QGIS2WEB white screen on export/preview

I got another question for ya guys about QGIS2WEB. When I export the project it goes through but when it loads up in my browser after the export is done all I see is a white background with the ...
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2answers
15 views

QGIS2WEB Error when exporting to Leaflet/OL3

I am having all kinds of problems with the QGIS plugins fr exporting my map to Leaflet or OL3. Whenever I try to preview my project I just get a white screen with nothing. Then when I try to Export to ...
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1answer
19 views

How can I save a QGIS project with hyperlinks?

I have already created an hyperlink project using actions, it works, when I click on one point of my shapefile it opens a photo, but when I re-open the project, the action is gone and I have to create ...
2
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1answer
74 views

Merging ShapeFiles with QGIS for UK counties

I want to draw a map for all the counties of the UK including Northern Ireland. Since I cannot find a source of counties including both Northern Ireland and Britain, I tried to merge two shapefiles ...
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0answers
12 views

How to create displacement vectors in QGIS using GPS points with different dates?

Is there a way to calculate and visualize displacement vectors in QGIS ? I have DGPS points taken at the same place (ground control points), but their position moved over time as they are located on a ...
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1answer
21 views

QGIS Plugins & Tools that replicate Select ArcPy Tools

I developed a complex python application for road generation from GPS Devices that uses a few Arcpy Tools. I want to try and replicate this Applications functionality using a freeware like PyQGIS ...
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2answers
31 views

How to get ST_MakeLine ready for QGIS?

CREATE VIEW new_line AS SELECT point1.gid, ST_MakeLine(point1.geom, point2.geom) FROM point1, point2 WHERE point1.gid = point2.gid; It's possible to load the layer but QGIS says 'There is no entry ...
2
votes
1answer
46 views

Update GPS coordinates to overlapped locations? is there a quick way to do so? I'm using QGIS?

If I have two many locations overlapped each other, and I want to update their coordinates to make the view clear and be able to spot the locations? How can I do this easily? I have more than 512 ...
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2answers
33 views

QgisInterface.addVectorLayer Error

I am Esri-trained, trying to move into QGIS using Python. Simply trying to add a vector layer in Qgis returns the below error: TypeError: QgisInterface.addVectorLayer(QString, QString, QString): ...
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0answers
20 views

PostGIS - How to calculate linestring length from WGS84 after transforming from OSGB 36

I am having problems getting lengths from multilinestrings after transforming data from EPSG:27700 - OSGB 1936 / British National Grid to EPSG:4326/ WGS 84. I'm doing this conversion to import a ...
1
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2answers
242 views

Tiled raster image to be placed in an OSM/ Leaflet.js map

I have a mapoverlay in a custom projection which I need to add as a layer to an Openstreet map within a website. Since I was not able to change the projection earlier, I decided to manipulate the ...
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0answers
15 views

line from min to max of a digital elevation model

I have some geometries as multipolygons and a dem (digital elevation model). I need a line from the max value to the lowest value of the dem for every multipolygon. Is qgis a tool i could use or do i ...
2
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1answer
61 views

How to export the map in very high resolution

I made a map in QGIS. Now I want to export the resulting image (layers upon layers) for further processing in GDAL. The print composer only lets me export an image up to a fixed size. If I try to ...
2
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0answers
39 views

Drawing “proportional” buffer using QGIS or GRASS?

I'm working on aquatic vegetation and have a shapefile representing floating vegetation in a lake. By some studies, we know that submerged vegetation extends for a certain extension based on floating ...
1
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1answer
27 views

Update points coordinates directly on the map using QGIS?

I have many locations or points overlapped each other, so is there a way using QGIS that I can update locations directly on the map using QGIS features, please let me know as I'm new to GIS.
2
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0answers
34 views

Why value relation doesn't work when I delete and connect reference layer?

I'm trying to connect reference table (domain) with data(text) to my vector layer (id's) using value relation. I have database in Oracle connected. It works fine, but when I delete the reference layer ...
1
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1answer
222 views

How to create cross sections from vector point layer in QGIS?

I have a set of points (X,Y,Z) across a river. Is there a way to present them as a cross section? I'm attaching a cross section I made in Excel: The X axis are the longtitude and the Y axis, the Z ...
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0answers
14 views

Vector data getting misaligned in final print in QGIS [duplicate]

My printcomposer view shows the data correctly aligned with background OSM/Google/Bing data but the final print makes it all misaligned. Data is in 3857 What can I do?
1
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1answer
186 views

Running GRASS functions in QGIS 2.4 from python console

I am using qgis 2.4 and i am looking for the "easiest" way to execute e.g. the r.in.gdal function from the python console in qgis. Specifically for r.in.gdal, I could not found this function in ...
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1answer
24 views

How do I enable lineweights for my symbology?

I imported an OSM shapefile of roads data. In the layer properties, I classified the roads based on type (motorway, trunk, residential, etc.). I can assign colors but cannot assign lineweights. I can ...
4
votes
1answer
187 views

Does QGIS have WMS-T (WMS with time) support?

Does anyone know if there's support for WMS-T in QGIS? Through the app I can add WMS layers, but I can't work with WMS-T (there's no place to set the time parameter). I been going through the the ...
2
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1answer
61 views

Put png map image as a background to draw upon

I have an image of a fiber optics network map: I want to turn this map image (without any actual GIS data) into a vector map where each point is defined by lat, long. To do this, I'm trying to ...
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1answer
30 views

find the population density of some points in qgis/postgis

I have the tiger census data of population density in each block group. I also have a different kind of data: traffic accident data, where an accident has a lat/lon pair. My goal is to find the ...
4
votes
2answers
105 views

Meaning of GCP in QGIS

Im a geomatics student, During a geo referencing with QGIS, a .Points file is saved. I open it with Notepad++ It is written under this form : mapX,mapY,pixelX,pixelY,enable ...
2
votes
1answer
40 views

different way to build qgis python standalone application

There seems to be 2 different ways to start a Python QGIS standalone script. The official tutorial is using : from qgis.core import * # supply path to where is your qgis installed ...
3
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2answers
360 views

Can I Dynamically Update Symbol Ranges?

Background: I'm currently trying to dynamically change the ranges for a layer with new style graduated symbology. Problem: I thought it may be as simple as updating the ranges for the existing ...
5
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0answers
624 views

Connecting ArcSDE to Quantum GIS for dummies?

I really have a need to be able to connect to and edit ArcSDE data in Quantum GIS. This question has been asked before and apparently is possible, but the instructions are just not specific enough ...
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0answers
13 views

QQIG/SAGA “merge shapes layers” algorithm removes underscores/pluses from layer names

I have a bunch of layers that are named layername_number+number that I want to merge. I need their names as source attribute so I used the "merge shapes layers" algorithm found under SAGA in the ...
2
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0answers
20 views

QGIS, faulty Zonal Statistics calculations in case of empty polygons

I run QGIS 2.10 on a 64-bit Debian system and am currently trying to do some basic raster vector statistics. However, I found that when applying the Zonal Statistics plugin, I end up with completely ...
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1answer
138 views

Integrate QGIS Server with existing Wordpress installation

How can I integrate QGIS Server with an existing worpdress installation? I have tried but cannot get capabilities to appear. Maybe something to do with Htaccess or httpd.conf but I cannot ...
2
votes
0answers
17 views

MMQGis plugin error

I am using QGIS 2.8.2 and I'm trying to geocode some addresses, but when I run it, I get this error: An error has occured while executing Python code: Traceback (most recent call last): File ...
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0answers
21 views

qgis atlas : problem with scale bar

Good afternoon, I'm working with qgis 2.8 (windows). I 'm abble to generate maps thanks to qgis atlas. But i have everytime a problem about the scale bar. When i generate atlas with "fix scale" ...
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0answers
28 views

Error: GRASS 7.0 and QGIS 2.8.1 in Linux Mint from the ubuntugis-unstable

I have installed GRASS 7 and QGIS 2.8.1 from the https://launchpad.net/~ubuntugis/+archive/ubuntu/ubuntugis-unstable (Trusty 14.04) in Linux Mint 17.1 64bit(sudo apt-get install postgis libgdal1h ...
1
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1answer
27 views

How can I create polygons for a 3D map from a DEM in grass/qgis

I have a SRTM 30m DEM of my area. I want to create a physical 3D terrain map from it (from felt, 3D printer, you name it). I have two questions about this process: With grass r.contour I created ...
7
votes
1answer
238 views

How to refer to another layer in the field calculator?

Is there a way to select an attribute from a polygon layer and insert the value into a virtual field of a point layer using "within" in the field calculator? CASE WHEN within($geometry, ...
2
votes
1answer
63 views

How to create multipe labels on polygons?

Is there any tool or function to create muliple labels on polygons? I've already created point geometries which refer to the polygon geometries but QGIS gets slower and slower with every new ...
2
votes
1answer
191 views

Import error when utilizing QGIS's Python Init function

Based on the answer to Referencing Qt UIs external to plugin with python. I'm trying to utilize the "Layer Properties / Fields / Python Init function" to execute a file (test_file.py) that is located ...
0
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1answer
40 views

How can we export shapfile to svg format using Pyqgis

I am doing a project where i have to export file from shapefile to svg format using Pyqgis. i have read some articles regarding simplesvg plugin but i don't know how can we achieve the same task using ...
5
votes
1answer
818 views

Can QGIS handle *.adf raster attribute data?

I have been trying to open Esri grid format (*.adf) files in QGIS. I can display the raster set itself, however, the appropriate attribute data fails to join the spatial dataset. Can QGIS display ...
2
votes
2answers
94 views

Merging linestrings in QGIS using PostgreSQL and PostGIS

I've to merge all linestrings from a PostgreSQL table "river" where not more than two start-/endpoints are overlapping. In the illustration below I use a "M" to mark all linestrings that needs to be ...
3
votes
2answers
1k views

Can I fix 'qodbc3:unable to execute statement' when querying SQL Server 2008?

I was testing features of QGIS and its really cool.I tried to query each table using right click and query but I can't query sql server 2008 database : Error: An error occured when executing the ...
2
votes
1answer
44 views

How to perform viewshed analysis with Dutch AHN files?

i downloaded the new (dutch hight data) AHN files, and was trying to perform a viewshed analysis at some point near UTRECHT. The plugin (grass plugin) works ok, i tried it before with a dem map. ...
2
votes
1answer
190 views

Split polygon into several smaller polygons in QGIS

I have a layer of polygons depicting response boundaries, I would like to break each of these polygons into a number of sub-polygons. As this is for an exploratory project, the polygons themselves ...
5
votes
2answers
2k views

Cannot see OpenLayers under Plugin in QGIS 2.4

Although I have installed the OpenLayers plugin, I cannot see it in the list when I click on Plugins. Does anyone else have this issue?
2
votes
1answer
32 views

Qgis2leaf doesn't show layers with scale-dependent visibility

When I add layers to the QGIS2LEAF dialog box it accepts it and opens up the preview in my web browser, but when I starting looking for the layers, in this case points for campgrounds, I dont see any ...
4
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1answer
57 views

QGIS Export Shapefile

i am trying to export selected feature using pyqgis. till now i have tried these codes. after using this i can select feature but dont know how to export selected feature to new shapefile. canvas= ...
6
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3answers
382 views

Finding centerline of peninsula?

Given a peninsula stretching north south and the two coast lines connecting in the south, I want to find out which is the place, or rather line, which is furthest away from both coastlines on the ...