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

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1answer
7 views

Checking layers with scale based visibility for visibility in QGIS

I am writing a Python method which I want the mouse click event to connect to. The method selects objects from layers that satisfy certain conditions. I want to select from any visible layer, that has ...
2
votes
1answer
43 views

Create points symbology with more than one parameter

In QGIS i would like to create symbology for points layer where the symbology will take into account more than one parameter (currently two). i.e.: My points layer has street names and house numbers ...
1
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0answers
17 views

How to refresh or update a vrt layer in Qgis?

When using the QGIS SpreadSheet Layers plugin, how do I update the SQLite query without closing and reopening QGIS? I cannot see a "watch file" equivalent. The plugin creates and uses a *.vrt file ...
2
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1answer
16 views

How to load stored composer from project file in standalone QGIS application?

I would like to load a .qgs file and get a composer from it, but I can't figure out how. Is there a way, or do I have to read the xml myself and individually set the appropriate values for the ...
0
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1answer
31 views

Point Sampler Python Error in QGIS?

I downloaded the point sampling tool for QGIS and I'm trying to run it. A few days ago it worked fine, but now it gives the following error: An error has occured while executing Python code: ...
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1answer
36 views

How to classify shapefile values in QGIS?

I would like to classify shapefile values using graduated style in QGIS, but instead of using the default mode of classification (e.g.natural breaks with values range 0-10, 10-20, 20-30), I would like ...
2
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0answers
34 views

How to add a map created in QGIS to a Matlab plot

I am generating a number of plots in Matlab. I want to overlay these over maps I have created in QGIS. I thought the best way would be to import the maps as a geotiff into Matlab and then overlay my ...
0
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0answers
19 views

Building Raster Attribute Table (RAT) in QGIS?

How can I build a Raster Attribute Table in QGIS 2.10 without using Python?
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1answer
25 views

Align and reshape polygons based on surrounding polylines

I am trying to use a shapefile with polygons and I am trying to align it to a road network, that the polygons align themselves to surrounding streets. Is there a way to automatize alignments between ...
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0answers
12 views

Module nziv not found in QGIS 2.10.1-Pisa

I want to use nviz in QGIS2.10.1-Pisa on windows 7 and I always get the same warning message : "Module nviz not found", whenever I click on it in the GRASS tools Modules list. I have tried to ...
0
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0answers
11 views

MrSID on QGIS 2.10 Ubuntu [duplicate]

i have Qgis 2.10.1 Pisa and GDAL 1.11.2, and i cant open MrSID (.sid) images en QGIS, i have lost three days trying to make it work, but i cant make it. My linux is 14.04 trusty tahr. Thanks ! ...
0
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1answer
31 views

Max Number of Feature Selection in ArcGIS and QGIS [on hold]

What are the limitations on the maximum number of features that you can select in ArcMap and QGIS?
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1answer
31 views

Is it possible to change the geometry without startEditing the layer

I am working in c++/QT 4.5 with the QGis 2.8.2 API. I had to change the geometry of features in a layer each second. Each second new data comes from the Ethernet connection, the application gets the ...
2
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0answers
16 views

What are the rendering options for timeline animations in QGIS?

I want to animate a shapefile that has a timeline (DATE) attribute using QGIS. The [TimeManager] plugin (http://anitagraser.com/projects/time-manager/) has been installed and provides sufficient ...
-2
votes
0answers
18 views

what is the script for pdf file hyperlink for a diffrent polygon diffrent pdf in qgis [on hold]

what is the script for pdf file hyperlink for a diffrent polygon diffrent pdf in q gis.and whenever we open that file any computer that time they not say create again script and path.
1
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2answers
56 views

How to show variable values in message bar in QGIS?

I know that I can write custom text to message bar with the QgsMessageBar.pushMessage() method. But if I understand the documentation right, there's no room for variables added to a string where they ...
1
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1answer
16 views

How to register a broadcast on QGIS to start my plugin on start after loading plugins

I want to perform a default task when user opens QGIS but here I am building it as a python plugin so I want a signal or broadcast to call my plugin. I didn't build QGIS from source my plugin should ...
1
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0answers
15 views

problem with view of open layer plugin map and swiss national coordinate system in print composer

Mi projects are in the swiss coordinate system (CH0193+ / LV95) and I use Open Layers Plugin for the base map (google streets). In the normal window, this seems to work fine: As soon as I open ...
1
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0answers
17 views

Output formats not showing in heatmap plugin (QGis 2.10.1 in ubuntu 14.04)

I just upgraded to QGIS 2.10 (using the debian repos) and the heatmap plugin doesn't show any formats in the dropdown menu. I'm able to open every raster format I have at hand and, of course, the ...
3
votes
2answers
79 views

Make a Qgis layer update from a changed data source

I'm trying to get layers to update automatically when their data source changes. I'm using R to write a shapefile with an attribute, and colouring according to that attribute in QGIS. I want to write ...
1
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0answers
13 views

access the encrypted table in qgis

I have a vector layer in qgis connected to PostgreSQL database table. Suppose I encrypt the table column using pgp_sysm_encrypt or some other encryption in PostgreSQL Is there any way i can say ...
1
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0answers
18 views

How to change programmatically the value of attribute in one of several feature in a vectorLayer

I have a vectorlayer that contains a lot of feature, I know that each feature has an unique Id Each of them has some propertie like coordinateX, coordinateY, color, name With a QTimer, each 2 sec I ...
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1answer
10 views

Building error on changegeometryvalues

I am working with c++/QT and c++api gqis 2.8.2 I want to change the geometry of a feature, I have this code : QgsVectorLayer * lLayer = mMapLayer.value(TRACKS); QgsVectorDataProvider * ...
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0answers
20 views

Is QGIS aspect analysis description mistaken?

I've been checking the Aspect analysis tool and several sources indicate that aspect is measured from 0 to 360, starting North and going counter-clockwise. Nevertheless, I've been testing it on ...
1
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1answer
15 views

Trying to create colour co-ordinated values on a map from data from a csv. file

I have a list of values for some data recorded via Magnetic susceptibility, I have these in a shapefile and want to try creating a colour map out of the values. The values that I'm using relate to, ...
0
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1answer
22 views

Why doesn't fTools Line to Polygon work?

I am working new with QGIS (Version 2.8.2 / Window 8.2) and try to make Polygon from Line (see example picture 1) with the fTool LineToPolygon, but it doesn't work (see picture 2). I work with ...
0
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0answers
13 views

how to rotate a symbol

I am working in c++/python/QT 4.5 with the api qgis 2.8.2 My application receive data from a communication port that indicate the change of position of an object diplayed on the map and represented ...
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0answers
26 views

Remove inner rings from QgsGeometry polygon in QGIS Python

I am a QGIS python user. I want to iterate over the rings of a polygon to remove holes in the polygon, so: I need to iterate over the rings in a QgsGeometry polygon I need to detect the main ring ...
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0answers
13 views

How to change the value tof the use tag in a svg file

I am working in C++/QT4.5 with the qgis c++ api 2.8.2 I have a svg file that contains different form tag by Id When i want the first form i place the id name in the use xlink:href="#formname" .... ...
4
votes
1answer
45 views

How to center a user-defined CRS on an area of interest?

My study extent in central Iran straddles two UTM zones (39 and 40): I would like to create a user-defined CRS in Transverse Mercator projection with central meridian inside this area. Through ...
1
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0answers
15 views

Toggling selected feature when using Node Tool of QGIS?

Does anyone know of a way, when using the Node tool in QGIS to edit a polygon, to choose or toggle which feature (within the same layer) is being selected if they share a boundary? It seems to just ...
1
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1answer
28 views

Selecting features within bounding box using QGIS?

What is the best way within QGIS to select all of the features within a rectangular bounding box? Is it necessary to create a separate layer with the box, then to use the intersection tool within ...
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0answers
23 views

Communicate relation between two table

At this time, I'm able to create a relation (1:M) between two table or geometries. After, I user Identify tool to exploit the relation. It is only possible to use this feature when your Identify tool ...
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0answers
21 views

Projected CRS interfering with Spatial Analyses?

I have come across a problem I am very puzzled about. I am working with two polygon shape files, one of which is a buffer around the other, and a point shape file in a project set to EPSG:54016. All ...
1
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0answers
15 views

Difference between adding spatial layer from MSSQL through “browser” and “add MSSQL table”

So I am trying to pinpoint the difference of adding layers from MSSQL Database that contains spatial layers like geography and geometry. I have noticed that when adding from the browser it retains it ...
1
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0answers
7 views

Change Volumes when saving outputs?

Im sure there is a simple answer to this but its eluding me. When saving outputs/QGIS projects the file navigator interface opens up and I can go through my files until I find the place I want to save ...
3
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0answers
24 views

How to display charts next to features in the map?

This question is meant to be primarily on QGIS software but all other software solutions are welcome as far as it is possible to achieve it as easy as possible, preferably out of the box. Though the ...
1
vote
1answer
35 views

Make a new shapefile from parts of two shapefiles

I have tried all day to connect two shapefiles and crop a part of them and save it in a new shapefile. In the image see two shapefiles and inside of the square is the part which I want to export in a ...
1
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1answer
50 views

Python script to copy first row of certain attributes and paste in the newly digitised rows the copied features

Starting from this question, I need a script to be insterted in the processing graphical modeler that can copy some attributes from the first digitised row in all the newly digitised lines of a ...
2
votes
2answers
30 views

Store in a python list the attribute table of a vector in QGIS

I'm stuck with a very simple issue.. I've loaded in QGIS (through the py console) a csv layer (no geometry) made of 4 fields and 3 rows: #load the csv layer = QgsVectorLayer("path/to/the/csv", ...
0
votes
1answer
42 views

How to remove points in QGIS?

I have way points of my field work, but some of points I saved are not related to my project. How can i remove them in QGIS?
0
votes
1answer
64 views

Is there something like a fast access for QGIS?

When I need QGIS only to check up something, opening the QGIS application takes way to long (on my computer: 5 minutes from double cklick on the the project until ready). I tried QGISCloud which ...
2
votes
0answers
20 views

SVG symbols are not available on other computers

I created some layers with SVG symbols. Those symbols are saved on the server, as it is not possible to store it in the database (postgis). Every computer can access to the server. But if I open the ...
2
votes
2answers
45 views

How to find the irregular polygons in qgis using python

I have a vector shape file and i want to find the irregular polygons. What are the parameters to be considered to check the iregularity of the polygon features? Calculating the perimeter and extent ...
0
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0answers
15 views

Geofence and GPS-Tracking in QGIS

What is the easiest possibility to create a geofence and to track if subjects cross the fence? I assume the fence is a simple polygon vector? What do I need for the cars? GPS data set? GPS layer? ...
0
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0answers
18 views

ORACLE Metadata Table used by QGIS?

When connecting to ORACLE Spatial with QGIS, QGIS Needs a metadata table about all available Geomtry columns in the database. If not provided, QGIS scans all tables with geometry columns wich can ...
3
votes
5answers
67 views

Is there any simple integration for counting points in polygon using python qgis?

Is there any simple integration for calculating count of points in polygon using QGIS-Python integration? In other words, are there any pre-defined functions for points in polygon of QGIS using ...
1
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0answers
10 views

measuring a distance on QGIS 2.2. in meters not degrees [duplicate]

Im using QGIS 2.2.0 and when I want to measure the distance on a map, the units are in degrees instead of meters. I have tried this : Right click on layer -> "Save as..." -> CRS: Selected CRS (WGS84) ...
0
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1answer
31 views

Can we count the points in polygon using pyqgis code? [duplicate]

Does anyone know how to calculate the point in polygon from the given points and the buffer output using python qgis. I have every thing loading the data and retrieving the output. But now I want to ...
2
votes
1answer
23 views

from tiff file extract values with QGIS

I have download a tiff file with elevation from http://srtm.csi.cgiar.org/SELECTION/inputCoord.asp and i try to export in file text or excel the cordinates and the elevation and i dont know how to ...