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

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11 views

How to randomly select three points in each polygon?

I have two layers: first layer includes polygons of districts, second layer containts points (phytocoenological relevées). The goal is to create a new layer that will contain max 3 randomly selected ...
2
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0answers
13 views

qgis 2.8.2 always produces minidump on exit

QGIS 2.8.2 on windows 8.1 produces the below error every time it is closed. Anyone have any ideas as to why or possible fixes ?
1
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0answers
13 views

Text box with automated coordinate reference system in use on Qgis

Using an expression, is it possible to automatically fill a text box placed on the map (in the composer) showing the reference coordinate system of the project? If possible, how would that expression ...
0
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1answer
16 views

Creating an intersecting linestring layer from two polygon layers using some tolerance

I have two postgis layers: The first layer contains the sidewalks of my town (polygons in blue). The second one contains the pavements (roads) of my town (polygons in brown). The map looks like ...
0
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1answer
29 views

How to find the intersection length between two polygons using python

I have two polygons and i want to find the intersection line length between these polygons. for geom1,geom2 in itertools.permutations(selection,r=2): intersection ...
1
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0answers
16 views

qgis python: select on screen and change (pre-set) properties accordingly

I have a map with different zones where I have drawn isochrones -where I will arrive within 15 min, within 30 min and so on. The picture attached shows the 15-120 min isochrones. This is set as a ...
3
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2answers
45 views

How to create a consecutive alphanumeric column in a QGIS attribute table?

I am trying to create a column in the attribute table such that each cell lable is a prefix (M) follwed by a unique number ie M1, M2,.. etc
3
votes
1answer
100 views

Way to find minimum value from a group of values - QGIS?

I'm wondering if there is a way to find the minimum value of a group within QGIS? Basically I need to find the minimum distance of each unique value in a table of about 5000 records. I can do the ...
1
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0answers
23 views

QgsVectorLayer from delimitedtext fails

I am having trouble loading csv files into layers using QgsVectorLayer(). I know this looks like a repeat, but I have carefully read Create a script to add delimited text layer in QGIS and ...
2
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1answer
32 views

How to create flow maps in Qgis

I have several records from a survey and would like to show flow map from places mentioned in the survey. I have all places mentioned georeferenced and some records mentioned no places and others ...
0
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0answers
12 views

QGIS to Leaflet Projection Weirdness

I've been using the mmqgis tool to create a hex grid. It loads up in QGIS looking good, but when I save it as geojson and load it up in leaflet it gets stretched (see attached). It starts life as ...
2
votes
1answer
42 views

QGIS LTR vs other release

Just after some advice with respect to the QGIS LTR schedule. Our IT managers have recently intervened in our use of QGIS (a State Government Authority) and are wanting to put in place a policy to ...
1
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0answers
8 views

Adding to signature list from ROI list does not work?

I'm trying out QGIS with SCP, but I've run into some problems First of all, my setup is as follows: QGIS version 2.10.1-Pisa on Mac OSX Yosemite 10.10.5 compiled and running against qt 4.8.6 ...
0
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0answers
20 views

How to use interacting PostgreSQL/PostGIS triggers in QGIS?

I use point geometries (table 'label_point') to place multiple labels on polygon geometries (table 'soil'). After doing layer edits I've to update the affected label_point features. Therefore I've ...
1
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1answer
37 views

change SRID of shapefile and QGIS

It is possible to change the SRID from a shapefile to another SRID in QGIS ? I have a shapefile in 2100 srid and i want to change it in 4326 SRID.
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0answers
14 views

QGIS 2.8 composer image

I have a table with photo's, i now want to make dynamic map with discription en showthe photo. In the composer with atlas, so i can produce about 1000 pdf files Is this possible?
3
votes
1answer
24 views

Problem exporting registers with the land registry in DXF continuation (suite) in reprojection

I visualize (display) a municipality with the plugin register with the land registry in spatiality and in projection Lambert 93. I need the bottom on Autocad in projection CC47 thus I re-throw ...
-2
votes
0answers
35 views

How can i make image of shape file using python in QGIS? [on hold]

Here I am trying to below code, but it give me error. import shapefile import Image, ImageDraw # Read in a shapefile r = shapefile.Reader("K:\TM_WORLD_BORDERS-0.3\Mississippi\mississippi") # ...
1
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2answers
54 views

Fix Polygons to be true Rectangles

I got a featureclass polygon of 4 point polygons that delineate the coverage area of a georeferenced image; these polygons will later be map sheets. Anyway I discovered some of them are not true ...
2
votes
0answers
29 views

Merge Line Segments based on their length in QGIS

I have a layer containing line segments which are connected by their endpoints (e.g. as within a street network). I'd like to merge (union) polylines within this layer into one feature until following ...
0
votes
1answer
33 views

Points and polylines representation of coordinates in QGIS? [duplicate]

I am working on the "Jakarta Bay", Indonesia. I have a shapefile for the Indonesian coastline and I clipped my region of interest using an appropriate polygon. I also have points that are located ...
1
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1answer
19 views

Cut/Clip/Split a polygon with another polygon from same layer (Editing) - Qgis 2.8.1

To not have overlapping polygons/features I normally use a practice where I use one or more polygons to clip/shape other polygons. This is often much faster than tracing when adding polygons etc. I ...
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2answers
30 views

About defining coordinate reference system

I have been wondering about the following issue for several years. In ArcGIS and QGIS you can add data on your map and it aligns perfectly even when the Coordinate Reference System (CRS) is not set. ...
0
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0answers
14 views

Grids stay visible in QGIS Composer Legend when turned off in project

I am using QGIS 2.8 to create a template for a dataset library. Lots of layers - vector and grids. The grids stay visible in the legend even when turned off in the map. I am using the "Filter Legend ...
0
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0answers
20 views

Viewshed analysis plugin on QGIS keeps resulting in errors

I've been trying to test the Viewshed analysis plugin on QGIS 2.10, but it keeps giving back error messages. I've tried to reduce the radius area and have also reprojected both my DEM and my point ...
0
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0answers
25 views

QGIS display wrong histogram statistics for float32 raster

While trying to display a float32 raster created with TauDEM, QGIS displays a min/max of 1,1 although the .aux.xml file contains the correct values. I am using QGIS 2.10.1 both on Windows 7 and Mac OS ...
1
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1answer
28 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
68 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
29 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
votes
2answers
29 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
votes
1answer
32 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: ...
0
votes
1answer
41 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
votes
1answer
40 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
21 views

Building Raster Attribute Table (RAT) in QGIS?

How can I build a Raster Attribute Table in QGIS 2.10 without using Python?
2
votes
1answer
29 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 ...
1
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0answers
16 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
votes
0answers
12 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 ! ...
1
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1answer
33 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?
1
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1answer
45 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
votes
0answers
23 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
19 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
vote
2answers
65 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
vote
1answer
18 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
20 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
20 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
89 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 ...
1
vote
1answer
11 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 * ...
1
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0answers
22 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 ...