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

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Calculating field on insert (real time) using QGIS?

We use QGIS as a field application. We like to calculate with a input value and then also calculate with the result of the calculation Example: Liters: 1000 -> Liter per container: "this has to be ...
-1
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0answers
17 views

How to add coordinates to an image in QGIS?

I use QGIS 2.10. I have a map image without any coordinate or boundary info. I need to convert it to kml file and before this, I need to add specific coordinate info for this map. How can I add ...
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0answers
10 views

How to visualize updating lines of bearing from a point

I'm working on a project where I need to visualize a constantly updating line of bearing from a point, based on degree of rotation around that point. My plan is to design a line feature with an ...
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0answers
11 views

How can I use a DBF layer in an R script in QGIS?

How can I use a DBF layer in an R script in QGIS? For example, I can input a vector by using ##Layer=vector, and a CSV table with ##Table=table, but it will fail if the table is based on a DBF file. ...
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0answers
15 views

Paths with least elevation gain

I have a DEM of a city with numerous hills and a shapefile of the city streets. I want to find the five paths from a low point A to a high point B on the street network that involve the least ...
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0answers
15 views

32Bit QGIS 2.10 Problems with Gdal WMS TMS google maps layer

I have been using gdal wms layers to view various basemaps in QGIS. I am using this technique rather than open layers because this I can reproject gdal WMS layers as needed. When I get close to the ...
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1answer
32 views

How can i calculate the distance to the nearest five neighbors for a polygon layer?

Data set (shape file) contains polygons. How can I calculate the distance to the nearest 5 polygons in the data set in QGIS?
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3answers
30 views

How to host QGIS threejs outputs?

Is there a free simple way to serve / host the .html files the awesome Qgis2threejs plug-in produces? I have tried using Google Drive as shown here and here without success. Also had same results ...
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0answers
17 views

How to show only some layers in the QGIS legend

I hope this is still kind of a QGIS related question. My QGIS 2.8.2 standalone app provides several decorating layers (e.g. cartographic grid, background layers, reference points) which should be not ...
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0answers
10 views

Zonal statistics shifted

I am working with QGIS (newbie). I have a raster map with 0.5degrees resolution. I created a 0.5degrees width grid layer and I compute zonal statistics from the raster. My problem is that it seems to ...
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0answers
28 views

Why I see a gap between ESRI Robinson WGS84 (EPSG 54030) VS QGIS Robinson WGS84 (EPSG 54030)?

Does anybody know why there a gap appearing between two point layers create with ESRI and QGIS when I a reproject, from the same source file, to Robinson ? The source coordinate system and ...
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26 views

Deciding variables for image classification?

The results of an image classification may vary A LOT depending on the variables you use from the beginning. Number of classes, minimum class size, sample interval, atmospheric corrections, ...
2
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0answers
29 views

Change number of cells in raster

i have 5 raster files and i want to merge them to one file with exact 50x50 cells because i have an R script to process it later. I used the arcgis function "mosaic to raster" but it delivers a ...
1
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1answer
24 views

is it possible programmatically to rotate a svg of the feature without rotate all feature

I am working on a project that need to move and update the shape of the feature of the layer. I am working in c++/ QT4.8.5 and qgis api c++ 2.8.2. In my Layer I have a lot of features, each feature ...
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0answers
18 views

Recast data from one geographic standard to another

I'm working right now a project looking at medical labour supply in rural areas in Australia. I aim to use STATA for most of this analysis, but a change in geographic standards by the Australian ...
2
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0answers
15 views

QGIS Set Composer Legend to shrink the font size to fit

QGIS 2.10.1. I have read that it is "impossible to make the legend smaller then its contents". Is there a way to set the legend to shrink the font size when re-sizing the bounding box? Or when you ...
3
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1answer
61 views

What projection to use to get a game map into QGIS?

I have built and maintain a SWTOR game map atlas. At the moment, it's all static jpg maps, but I would like to get the info into an actual GIS software to get more functionality and make my website ...
3
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0answers
20 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 ...
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0answers
20 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 ?
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0answers
15 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
20 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 ...
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1answer
41 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 ...
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0answers
21 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
79 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
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2answers
121 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 ...
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0answers
26 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
47 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 ...
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0answers
13 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
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1answer
47 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 ...
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0answers
11 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 ...
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0answers
24 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
20 views

QGIS 2.8 printcomposer show image dynanic

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? The photo's are ...
3
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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 ...
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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") # ...
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2answers
58 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
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0answers
35 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
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1answer
35 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 ...
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1answer
20 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 ...
1
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2answers
37 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. ...
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0answers
16 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 ...
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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 ...
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0answers
26 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 ...
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1answer
31 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
69 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 ...
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0answers
31 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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2answers
30 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
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
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1answer
43 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 ...