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

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30 views

Analysis of MODIS 16 Data Set

I have downloaded the raster data sets of the Evapotranspiration data for about 10 years. I need to analyze those raster data sets. Which tool can I use? Or do I need to download a certain plugin. ...
2
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1answer
37 views

Does mapCanvas().refresh() not work in QGIS 2.6?

Before I used the function qgis.utils.iface.mapCanvas().refresh() to reload the map canvas after for example a layer color was changed from a plugin. But this is not working with QGIS 2.6 for me. ...
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1answer
62 views

How to export only certain column from selected feature to csv file in QGIS using python code

I have selected features in QGIS, I want to export only two columns from the selected features to a csv file automatically using python code. I have tried the following code: layer = ...
3
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2answers
47 views

How to define layer's CRS and avoid the CRS dialog in PyQGIS?

There is an existing Shapefile, which I want to add. At the moment my code looks like: self.iface.addVectorLayer(self.shpFilePath, "Track", "ogr") It works fine, but i want to define the crs ...
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1answer
47 views

Download file from network using PyQGIS 2.x

I have a python plugin targeting QGIS 1.8 that uses QgsNetworkAccessManager and QNetworkRequest to issue a GetCapabilities request to WMS servers. With 1.8 everything was working fine. Now we are ...
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1answer
19 views

Turn off the setting of QGIS to produce xml when closing

Every time I open and close a raster layer in QGIS it creates an xml file for that raster when closing. While I do a lot of automatic processing this really bugs me, since I have to add every time ...
2
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1answer
42 views

How do I unselect features in ONLY the current layer in QGIS

So, I hope this is an easy question, but: How does one unselect features only from a certain layer? I know there's the Deselect features from ALL layers button. But that's extreme. Is there a simple ...
1
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1answer
36 views

Creating Isochrones with pgrouting - Network set up, locations (from point shapefile) imported into PostgreSQL/PostGIS DB and now?

I want to calculate isochrones representing the accessability of certain locations in a city. So I have set up the pgrouting enabled database, imported the OSM-Roads and created a network (thanks ...
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1answer
42 views

Merging polygon and line shapefiles into one using QGIS?

I have two shapefiles: One is a line feature of the rivers and waterways of London, the other is a polygon feature of the reservoirs, lakes and ponds of the same area. Is it possible please to merge ...
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0answers
13 views

How can I export a route from Qgis Roadgraph plugin?

I've created a route with qgis roadgraph plugin, and I want to create a shapefile (line) from this. I've tried with export, and save as .shp, but the new shapefile doesn't show the line!
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1answer
35 views

How can I create point to lines intersection qgis?

I have two line layers, and I want to create a point where they cross each other. How can I solve it in Qgis?
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1answer
35 views

What's the PostGIS equivalent to Extract Nodes in fTools / QGIS? [duplicate]

I'm looking to convert Park polygons from OSM into points. The QGIS fTools Extract Nodes tool will convert a polygon to points at the vertices. What is the equivalent function or work-flow in ...
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1answer
19 views

QGIS multiple whitespace in attributes are removed after restart [on hold]

Concerning this question: http://stackoverflow.com/questions/28660079/firefox-is-ignoring-more-than-one-whitespace-in-svg-text-and-showing-them-smalle I have an issue with the saving of Strings with ...
3
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2answers
67 views

How to compute average slope and area-weighted average slope?

I am learning GIS for use in hydrologic analysis. Related to computation of overland flow there are two types of slope that I would like to be able to obtain from GIS. The first is average slope for ...
2
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1answer
71 views

Can't open projects with qgis. Why? What i have to do?

I have an essential problem with QGIS, that I had both with version 2.2 and now with 2.8. I can't open the projects that I have saved. It is a project of 4 layers: a vector with a region of ...
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1answer
23 views

extract 1st level boundaries from GADM worldmap in QGIS

I need a world map, broken down to GADM 1st level. The obvious way would be to download all single country .shp files and merge them. But that is far too tedious of course. I tried the dissolve ...
1
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1answer
25 views

Is there an out-of-the-box way to manage 1:n data in QGIS?

I think an image explains the question best: What I basically want to do is select the object, view its attributes and from there call the second table to view/edit/add status entries. Since I ...
2
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1answer
45 views

Adding new menu item to QGIS Desktop app

I need to add new menu item to the top level menu of QGIS Desktop (2.7.0); I.e. it shall be on same level as "Project", "Edit", "View", "Layer" etc. As far as I know there is pretty nice way how hide ...
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1answer
33 views

Shapefile to KML Conversion Problems in QGIS 2.6.1 on Mac

I am currently using QGIS 2.6.1 on a Mac with OS 10.9.5. I am trying to export a shapefile using QGIS to KML format. I am having success with the export but the data is skewed halfway across the ...
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1answer
42 views

QSpatiaLite Plugin: LINESTRINGZ(x y z, …) supported?

I get an error when trying to import this query as a spatial table in QGIS: select geomFromText('LINESTRING Z(13.091464 47.061328 2597, 13.092059 47.061287 2580)') as geometry 'The result can't ...
1
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1answer
28 views

How to check the value of a single pixel in QGIS?

I was wondering how to check the value of a pixel at a mouse click in QGIS (as of 2.4). In ArcGIS, the "Identify" tool does the job for both rasters and vectors. However, in QGIS, the "Identify" tool ...
2
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0answers
22 views

QGIS Python Script for RoadGraph plugin

I am looking to create a Python script that will take X,Y coordinates from one field in an attribute table, compare them to another set of X,Y coordinates in a different field, and populate a field ...
2
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1answer
39 views

Issues with PyQGIS while running a QgsZonalStatistics script

I have experienced a very bizarre issue with my PyQgis code. I simply want to load a raster and a vector layer to do zonal statistics, the first part works perfectly but for the zonal statistic I have ...
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1answer
42 views

How to use delaunay triangulation in QGIS?

I have to create a thiessen polygon for a site in New Jersey and All I have right now is the concentrations from samples we took in the area. What else do I need and how to i input it into QGIS to get ...
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0answers
26 views

How to change the attribute values of the feature using the custom feature form

When i am using the following command it opens the feature form with all the fields: qgis.utils.iface.openFeatureForm(qgis.utils.iface.activeLayer(), f) But i want to open a feature form with the ...
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0answers
29 views

How to display Google Earth on QGIS? [duplicate]

How to display Google Earth on QGIS ? Is there some plugin easy to set up ? Thanks a lot
2
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0answers
20 views

QGIS extremely slow to clip vrt on Mac

I've been using QGIS 2.6 (Brighton) happily for awhile but suddenly it became extremely slow during certain operations, after being reasonably fast in past use. I'm merging NAIP JP2 files to virtual ...
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0answers
23 views

Inflating the boundaries created with convex hull

I have a set of lan and lat points and have plotterd a convex hull for them using QGIS. A polygon is created along the set of points and plotting them on the MAP. Now I am trying to inflate the size ...
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2answers
27 views

QGIS dividing a raster by a polygons layer

I've got a raster image and I want to divide that raster by a polygon layer. There are just 7 polygons in the layer so i need to obtain 7 raster images as output. How can this done in QGIS?
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1answer
38 views

How to compute buffers for certain features?

I used the following snippet of codes for finding buffer. def buffer(self): layer = self.iface.activeLayer() distance = float( self.dlg.DistancelineEdit.text() ) city = ...
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1answer
28 views

How to connect mouseclick to map canvas in QGIS?

How to connect mouse click to map canvas in QGIS using python script? I have two lines of code to connect mouse click to map canvas: button.clicked.connect(self.onClicked) ...
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1answer
36 views

QGIS/OpenLayers - How to add a “labels-only” reference layer (basemap focused on labels)?

In ArcGIS you can add a "reference basemap" which features labels for key locations as in: http://www.arcgis.com/home/item.html?id=8b3d38c0819547faa83f7b7aca80bd76 however, in QGIS, I cant figure ...
2
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1answer
35 views

How to visualize car park occupancy over time?

I am using QGIS Brighton 2.6.1. I have a csv table with the exact entrance datetime and exact exit datetime of every car in an specific parking. Example of table: Nº DateTimeEntrance ...
3
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1answer
69 views

How to import fromUtf8 in QGIS?

# Declare instance attributes self.actions = [] self.menu = self.tr(u'&City_searcher_plugin') # TODO: We are going to let the user set this up in a future iteration self.toolbar = ...
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0answers
19 views

How to update Trackball controls at three js

I have a project at three.js created from qgis to threejs export where i need to update the trackball controls on window resize.. I need to do that updating the whole controls calling the function ...
0
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1answer
22 views

Keeping no data values in clipped rasters

I am using QGIS and I have a raster layer with temperature values. The ocean has "no data" values, since I need only terrestrial information. I need to clip this image to retain only one part of the ...
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0answers
16 views

creating composite raster tiles from multiple vector layers as new background map in QGIS

I have been patiently restyling OS Vectormap product to create a map background I'm happy with, which i want to now use as a background for a leaflet map using QGIS2leaf. I understand that performace ...
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1answer
49 views

Determining Projection using QGIS?

I am very new to QGIS and I am trying to determine the spatial projection and the units of distance of a certain raster file. The closest thing I can find is the CRS, which is set to some sort of ...
1
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1answer
46 views

convert vector (point shape) to raster (tif) using python gdal lib in qgis

I'm trying to convert a vectorlayer (point- shapefile) to a raster-dataset (tiff) using python gdal-library in qgis. On Graphical UserInterface I simple choose the menue ...
0
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1answer
45 views

How to trigger a QGIS action when a plugin button is clicked?

I tried calling the select free hand tool by below snippet of code. iface.actionSelectFreehand().trigger() I dnt have any idea how to call this when i am pressing a button in GUI. my gui is ...
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0answers
26 views

Error in my buffer plugin

In my buffer plugin, i tried the following code # Get buffer distance and selected city dist = float( myLineEdit.text() ) city = myComboBo.currentText() # Get the feature corresponding to the ...
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0answers
32 views

Which version of the Oracle Client do i need to get Oracle support in QGIS 2.6.1?

I have just installed QGIS 2.6.1 and wish to connect to our Oracle Spatial 11g Database. Am I correct in thinking I will need the Oracle Client installed on my machine for this to work? If so which ...
2
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0answers
41 views

Is there a way to (helpfully) give feedback on QGIS Training Manual?

I'm just working my way through some of the current QGIS Training Manual: http://docs.qgis.org/2.6/en/docs/training_manual/ As I work through it I am coming across occasional things which are ...
2
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1answer
31 views

Problem with creating a model in Qgis — select by location

I have two shapefiles (polygones) - referentiebestand and oudejaren -> the first step is to calculate the centroids of each shapefile (gives a good result), then a create a buffer around one of this ...
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1answer
49 views

How to call default tool in QGIS inside plugin using python script?

I want to create a plugin which can draw irregular polygons in QGIS. For that, I want to call the Select features by freehand default tool inside my plugin. How can I do this within a python script?
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1answer
55 views

How to connect Excel file with QGIS?

I am working with QGIS and I want to connect with Excel. I have exported attribute tables to Excel. Now I want to connect Excel with QGIS in the way that if I change a line dimension, it will be ...
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0answers
21 views

How to highlight joined features?

I have a task in QGIS (2.6), where I need to join two tables through an action (I think). I have some projects (points) that I need to connect to a list of partners (also points). I have data in both ...
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0answers
23 views

Mask plugin, Atlas composer and Legend

I'm tryin' to use the mask plugin associated with atlas composer (QGIS 2.7 dev). I'd like to have in the legend of map composer only the features that belong to mask instance (inside the mask). if I ...
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1answer
37 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 ...
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0answers
15 views

Export DXF Issue in QGIS?

I got the shapefiles in QGIS and transformed them to UTM NAD83 from WGS84, then tried to create a DXF of it so I could use it as an overlay in fieldgenius software for a topographic survey we're ...