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

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need information about openstreetmap (osm)

I am looking for information or code sample to use OSM map I am working on a project that need to read OSM and to display it I intend to use the QgsOSMDownload and more But at this time i need ...
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14 views

import qgis.core problem with QgsFeature and QgsGeometry ImportError: DLL load failed: The specified procedure could not be found

I've tried several previous answers to similar questions - no luck. I've tried everything, nothing seems to work. This is the error I'm getting Traceback (most recent call last): File ...
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0answers
7 views

Qgis Time manager raster error

I would like to give a shot to the Time manager in Qgis with some raster datasets. I load 2 rasters (both single band, 32bit float). I add the first one in the Time Manager window with the start ...
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0answers
9 views

How to graph a line given a great distance (e.g. 100km) and the angle?

I'm new to QGIS and I'm trying to graph subduction zones and I was given the starting point (in latitude and longitude), the length (in km) and the angle (in deg). How is it graph correctly? I tried ...
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1answer
18 views

How to measure the distance between multiple points and multiple polygons?

I'm trying to find a quick and accuarate way to measure the distance between 3 survey sites and all the designated sites within 10km. The survey sites are on a point vector layer and the designated ...
2
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1answer
24 views

QGIS Heatmap values change when imported into ArcMap?

I am creating a heatmap layer from QGIS and importing the TIFF into ArcMap. When I import the file into ArcMap I notice that values are different. For example the max value in QGIS is 8.92454, but ...
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1answer
11 views

Semi Automated Classification plugin (QGIS) error when trying to create ROI

When I try to create a new ROI through Semi-Automated Classification plugin (SCP) for QGIS, I keep getting a message saying: "It appears that SciPy is not correctly installed. Please, see this page ...
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0answers
16 views

How to remove las2dem streaks from raster dem

I've created a series of DEM files using the las2dem tool from LAStools, however since I don't have a licensed version they have black streaks running across them. Does anyone know a good method for ...
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1answer
26 views

Update Column in QGIS

I would like to update columns in QGIS something like making MAPINFO . Contains , is Within, intersects ) and get values ​​such as sum, avg, propsum , count Is it possible to do this with any tool in ...
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0answers
12 views

Normalized Difference Built Up Indice with a threshold value in QGIS modeler

I want to use the modeler in QGIS, model the NDBI with a threshold value in order to produce a binary image. positive values = 1 and negative values = 0 my question is about which tool I can use in ...
3
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1answer
28 views

Overlay Analysis in QGIS (or Preferably Python)

I would like to perform an overlay analysis in Python or QGIS to output a list of each shapefile that falls within certain boundaries. I have unsuccessfully tried to use the Spatial Join, Intersect, ...
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1answer
29 views

Interpolation extent

the following pics will hopefully explain my problem. After interpolation an clipping the grid I get the result you can see on the pic. Next to the boundaries there are a lot of gaps caused by the ...
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1answer
25 views

How to merge two lines of polygons?

In QGIS 2.6.1, I have merged two polygon shapefiles. After merge I am facing problem at boundaries.. So I thought of changing Polygon -> lines(manually deleting one of the line at boundary) ...
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1answer
18 views

How to show objects inside an area?

I have two different shape: point shape file with many elements area shape file with many regions I need to create a rule where I need to colur differently the points in some areas, but the areas ...
1
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1answer
31 views

Is there a way to set the character encoding for all layers at once?

I have to set the character encoding forall layers from system to UTF-8. Is there a way to change this in all loaded layers at once? I'm using QGIS 2.8.1 on Windows 7.
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2answers
48 views

Problem when opening a raster layer

I am a news user with QGIS API C++. In order to feel good with it I try some little program to explore class. I have download the tutorial 4 of the QGIS and adapted it to the 2.8 version but when I ...
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0answers
21 views

How to use r.mapcalculator to change values within a raster cost map to negative

I have created a cost map in r.cost module in GRASS (through QGIS). This is actually a distance map from a protected area and distance from protected area has been calculated in both directions. How I ...
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1answer
32 views

How can i fix the dock widget to the the Qgis window using python

I am creating a dock widget for my plugin and i want my widget to be fixed to the Qgis window. How can i do that using python programming?
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1answer
20 views

How to get programmatically selected layers from the QGIS legend?

My QGIS plugin exports all layers from QGIS to KML format. Now I'd like to export only selected layers. However, I can't find any hints in QGIS API. Is it possible to iterate over selected layers in ...
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0answers
10 views

How to import or reproject SRTM 30 sec DEM [duplicate]

I downloaded the global SRTM DEM from here. When I add the DEM as a raster layer (in my case topo30.grs file) the left/western edge of the file is at Greenwich and the right/eastern edge is at +360 ...
2
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1answer
27 views

PyQGIS standalone script does not work. Error “QGraphicsScene::addItem: item has already been added to this scene”

I try to test a PyQGIS standalone script which should just show one Shapefile. Sounds pretty simple but does not work. Here is my script: from PyQt4 import * from PyQt4 import * from PyQt4.QtCore ...
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0answers
26 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
30 views

Loading .shp file into QGIS gives error message

When I add vector layer I select the .shp file and nothing happens When I add vector layer and I select the folder it gives error message "not a valid or recognized data source" The pop up box queries ...
2
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1answer
33 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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0answers
15 views

Lines > Polygon artifacts

I am trying to make polygons from a set of boundaries from an SVG file with closed polylines I downloaded off wikipedia. 1) convert SVG to DXF via Inkscape 2) import into QGIS (shows polyline data) ...
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24 views

NDVI from raster to vector isnt working

I have question...can I make from raster img. vector file via qgis? Because Ive tried it on NDVI image and Ive only got one file with atribut table full of #null. Image is from landsat7... ...
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19 views

Obtaining NDVI data from selected area

I need to analyse NDVI (-1/1) change between years (05-10y). But still only under selected shapefile. To analyse the extent of each NDVI category. Any tips? I have tried to make vector from the NDVI ...
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1answer
36 views

“Browse” button returns python error in QGIS

I use the latest version of QGIS (2.8.2) in MAC and have se the default Python version 2.7. Moreover, I have installed all the required python modules and GDAL. It was working before, but now, when I ...
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1answer
19 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 ...
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0answers
23 views

Placing road labels only at map edges and road intersections in QGIS

I want to place road labels only near the map edges, and where roads intersect - as depicted by the red X's in the image. Background: I've seen the military do that in their topo maps, and I think ...
2
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0answers
18 views

Help Needed with QGIS Vector->Geoprocessing Tools->Difference [duplicate]

I'm trying to use the Vector Geo processing Difference Tool in QGIS to "take a bite" out of one polygon using another in another layer. The tool menu Difference icon is exactly what I'm trying to do - ...
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1answer
29 views

Create ID for each string attribute in QGIS

I'm trying to rasterize a vector layer by using an attribute filed stored as string, I got the confirmation through the GDAL mailinglist serv that gdal_rasterize does not work with string field. So my ...
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2answers
32 views

Where to get QGIS toolbar icons?

Does anybody know where to download the QGIS toolbar icons?
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1answer
20 views

How can I overlay city and borough names in QGIS with political boundaries?

This post is related to this one. The following images are from @Weinfried's answer. I was able to get the ITA_adm0.kmz, ITA_adm1.kmz, ITA_adm2.kmz, but not ITA_adm3.kmz, which for some reason does ...
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1answer
26 views

QGIS Coverage help

I am using QGIS 2.8.2 and everytime I try to load in a coverage type Shapefile, like forest density or population density it all comes up as the same color, but has the sections marked for the ...
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1answer
22 views

Generating elevation 'database' from NED IMG data

I'm starting to work with the NED 1/3 and 1/9 arc-second data. I've been using gdal in Python and QGIS to do some basic conversions of the raw .IMG data from USGS. My goal is to get elevation data of ...
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0answers
13 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? THIS is an URGENT volunteer ...
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0answers
22 views

How can I render heatmap contours from QGIS into tiles?

I have a heatmap and contours in QGIS, and I want to export these heatmaps as tiles. This works well with tiff, but I want to include contours into images, to make them look better. In QGIS, I can ...
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0answers
15 views

Loading Batch Parameters in QGIS [on hold]

I usually work my batches in Excel and then copy/paste it into ArcGIS batch UI. Is it possible to do the same in QGIS? The tutorials I've seen show how to fill the interface line by line, only. I'm ...
1
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1answer
27 views

Adding the map canvas center to a composer label in QGIS

I am able to access the map canvas center in the python console in QGIS using qgis.utils.iface.mapCanvas().center() What I would like to do is get this into a map composer label. Is this ...
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0answers
18 views

How to format the labels of a UTM Grid in a map Layout/Print Composer

I am doing a map in for a small area (1.5km by 1.5km on UTM zone 14N). I want to know if it is possible (and how to do it) to format the labels of a UTM grid. This is exactly what I want to show a) ...
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0answers
19 views

QGIS DB-Manager: How do I hide a geometry column?

I created a table on a SpatiaLite DB using the DB-Manager: CREATE TABLE Lines ( line_id INTEGER NOT NULL PRIMARY KEY, name VARCHAR(256) NOT NULL); Then I "made it spatial": SELECT ...
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1answer
45 views

Calculating Area of Intersecting Polygons and Buffers

SO, in QGIS I have several points with 1km buffers around them; some of the buffers overlap. Within the buffers are a number of ponds, which I have a shapefile for. I want to calculate the area of ...
2
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0answers
12 views

QGIS create a line graph with attributes value on a section through the map

I wonder if I can make cross sections of GIS data (other than height). An example: I have a shapefile of a city with building plots and attribute values of the plot size. I want to choose a random ...
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0answers
11 views

Shifted point in pdf export on QGIS

When I print as PDF a work done with a shape point and OpenLayer plugin I notice that the point are shifted In the dual screen image you can see the pdf exported image (left) and the QGIS woriking ...
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0answers
17 views

cannot load moule sip qgis 2.8.2

i have an error when i launch the qgis 2.8.2 it says that the module sip cannot be load python 2.7 has been installed i am under ubuntu 14 please if you have any idea here is the message (in french ...
2
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1answer
19 views

PostGIS - interfacing with CADCORP 7.1 and QGIS - user 'postgres' can import, but no other roles can

I'm new to PostGIS (reasonably) - but I'm plagued with one on-going problem: I'm able to access PostGIS from various GIS systems using the main 'postgres' user. Using a newly created user ...
2
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0answers
35 views

How to edit the GUI of a QGIS plugin not made with the plugin builder?

I edited a python plugin's code and had to change the UI a bit as well. However, unlike in the plugins I made from scratch with the plugin builder, the UI doesn't automatically update in QGIS when I ...
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1answer
36 views

Setting PYTHONPATH for compiled QGIS version on Linux

I'm trying to set the PYTHONPATH in order to be able to load the qgis classes in a python console (not the QGIS Python one). I followed some resources I've found (PYQGIS Cookbook, and others) but I ...
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1answer
53 views

How to register “events” for linear referencing in pyqgis?

Is there an easy solution for recording events for a line crossing borders of zones in a polygon layer? I need to implement this in python using QGIS, thus pyqgis. The image attached illustrates what ...