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

learn more… | top users | synonyms (1)

2
votes
1answer
411 views

How to delete a column from the attribute table of a SpatiaLite layer?

I want to delete a column from Attribute table but the function "Delete columns" isn't highlighted. (When I am adding new layers I use New SpatiaLite layer, not Shapefile layer). So I have installed ...
1
vote
1answer
71 views

How to select from selection with PyQGIS?

The expression box has a handy "select from selection" button. Is there a way to emulate this with python? I have the basic expressions down, but can't find a way to do this.
1
vote
0answers
58 views

How to load “soil types” in QGis?

I want to show soil transmissivity per pixel. Thus, I determine water holding capacity of each pixel (ignored other effective parameters). Respectively, I wonder, What is the soil data format and How ...
2
votes
3answers
67 views

QGIS python plugin appends values every time it's started

I've written a small python plugin (using plugin builder as base) to simplify the expression process for a given layer (just a few comboboxes that are used to create a query). The combo box populating ...
1
vote
0answers
57 views

Problem between files with same coordinate reference system

I have 2 shape-files. The first created with Qgis and the other with R studio(driver=ESRI). When I import them in qgis i see they doesn't "fit". Both have EPSG:4326 - WGS 84. The only difference I ...
1
vote
1answer
178 views

new layer from calculations with fields of other layers in QGIS

I've two layers, both with the same fields: A, V, where A is the shape's area and V a value given by me. I want a new layer with shape created by the intersection of the other layers' shapes and a ...
1
vote
1answer
101 views

Problem with QGIS - Attribute names are shown as _1,_2,_3 … and Strings are displayed as “NULL”

Whenever I look at the attribute table or at the attribute dialog for a shape, the attribute names are shown as _1,_2,_3, ... In the attributes, Strings are generally displayed as "NULL". Numbers are ...
2
votes
1answer
283 views

Why processing.runalg(“gdalogr:rasterize”…) is not creating out files when running in the QGIS 2.6.0 console?

I want to use the QGIS python scripting functions to turn to rasterize a point vector using many different dimensions. Right now my code looks like this: import processing RasterPixelSize = ...
1
vote
2answers
269 views

Can't compile plugin builder plugin in QGIS 2.4 (Windows)

I'm trying to build a basic plugin using plugin builder but I can't even compile it. I tried following a few tutorials and just trying to compile whatever but that always results in the same problem. ...
1
vote
0answers
108 views

In QGIS heatmap howto establish a fixed maximum range value for comparisons over time?

I have several data sets that represent a type of activity within a specific geographic boundary. Each heatmap I create shows the relative activity spread nicely, but I have been frustrated in my ...
3
votes
2answers
1k views

QGIS and Ubuntu 14.04 unmet dependency

I posted this on digitalocean, but it's imperative I resolve this problem. Freshly updated 14.04 and I went from trying qgis.org debian to the ubuntugis repo. Results: xx@XX:~$ sudo apt-get install ...
0
votes
1answer
45 views

Workaround for grouped layers to stay collapsed when opening project

Using QGIS 2.6.1 on Windows 7, whenever I open a project containing layers in various groups, they appear expanded. This is regardless if the project is saved when the layers are collapsed. I'm ...
2
votes
4answers
2k views

How to convert a vector map to raster in Qgis?

I am creating a thematic map (vector data) with different classes. How to convert this vector map to a raster map, keeping the classification?
3
votes
1answer
414 views

Can QGIS 2.8 load WMTS layers?

I'm having a bit of an issue loading a WMTS into QGIS 2.8. The application can connect to the WMTS, correctly identify the layers that are available and load the layer into the layer pane. However, ...
5
votes
3answers
2k views

Error when creating a new mapset with GRASS in QGIS

When I try to create a New Mapset with the GRASS plugin in QGIS I get an error or the program crashes. QGIS 2.6.1 (32-bit install, Win7). QGIS crashes completely when clicking "Finish" in the New ...
1
vote
1answer
78 views

Rotation matrix in the EPSG

I use Proj4j for a WebGIS and I have to create a new ESPG. I tried on QGIS to convert coordinates from a local system (in Greece) to a world coordinates system. First, I have to do a 2D ...
1
vote
0answers
39 views

How to get rid of lines within merged poligons?

Sometimes, when I merge polygons there are still some lines showing within them (see screenshot). How can I get rid of them?
2
votes
1answer
112 views

Identify tool and highlighting behaviour in QGIS 2.6

I have a problem with the identify tool in QGIS 2.6. Somehow the object highlighting doesn't go off when i click on another object with the identify tool in QGIS. In earlier versions, when you ...
2
votes
0answers
44 views

Extract from a linestring layer, groups of linestrings to a multilinestring objects layer

I've got a linestring layer with thousands of linestrings. I want to extract groups of linestrings to individual multilinestring objects. In the following picture you can see a part of the layer ...
0
votes
1answer
47 views

QGIS and arcmap compatibility in image georeferencing

I have georeferenced an image in QGIS but when I imported it to arcmap 10.0 it saying "In consistent extent". Any one know how to solve it?
1
vote
1answer
57 views

Current field of view specific legends in QGIS

Is it possible to make QGIS generate a legend that is based only on the field visible in composer? There was a ticket marked as resolved 5months ago with this question but it doesnt divulge the ...
1
vote
0answers
30 views

Worldfile incorrect? Puzzler: all resources supplied!

Trying to manually create a worldfile for gif images of surface currents supplied by the navy here. I have QGIS and am decent at using it but the world file tool is failing without error on me (even ...
2
votes
1answer
94 views

QGIS Merged Layers/ Cannot Find Windows “minidump” to Restore Past version off Dropbox

I've copied a layer style and was playing around with the display of a point layer when QGIS Valmiera 2.2 crashed. A recently-created polygon layers attributes are now appearing in the place of ...
1
vote
1answer
166 views

Unable to change the fonts of the legend in QGIS 2.8

I'm running QGIS 2.8.0-Wien on my Ubuntu box and came across odd behaviour of print composer. When adding a legend - I'm unable to change the font size of the title and items. Bizarrely - in the ...
4
votes
1answer
152 views

Measuring Sinuosity of Walking Paths

I'm currently working on a project that examines the movement of consumers through different kinds of retail spaces in Central Asia – namely, bazaars versus supermarkets. I've equipped dozens of ...
3
votes
3answers
891 views

SAGA installation in QGIS 2.8 on debian linux

I install QGIS 2.8 in debian (linux) through nightly jessie (qgis testing) and I see that SAGA is not in processing toolbox, so I install saga gis software but still it doesn't appear in processing. ...
0
votes
0answers
57 views

Layout points along a line at varying distances

I am new to QGIS, and have some minor experience with ArcGIS. I am trying to lay out sewer taps (connections) along existing sewer main lines in QGIS, from old construction notebooks. The lines run ...
2
votes
0answers
22 views

How to create a syntesis map ( eg. climatic vulnerability) in Qgis [duplicate]

My final goal is to create a synthesis map of climatic vulnerabilities composed by different thematic variable with different weights. I would like to ask for support for the following issues: For ...
1
vote
1answer
231 views

Error adding MrSID raster layer to QGIS for Mac OS X 10.10.2 (Yosemite)

I want to add a MrSID layer to QGIS (version 2.6.1) with a computer running Mac OS X Yosemite. I installed QGIS through macports from the terminal and all python packages through macports, as well. I ...
4
votes
1answer
306 views

How to calculate “water accumulated in each cell” using QGis?

I create channel network and catchment area from a DEM with SAGA GIS. I know that flow is starting from a cell to an other cell. Firstly, a cell is filled with water and then it is starting to flow ...
6
votes
2answers
506 views

How to make a bivariate colour ramp with QGIS, R or similar?

Many recent maps I have seen have these neat two-way color gradients that can be used to color correlations between continuous estimates. Here is an example taken from a recent publication (Source: ...
3
votes
1answer
788 views

How to get a layer by name in PyQGIS?

I have a plugin which finds buffer for list of cities, provided the distance. The state and city names are taken from the attribute table and gets filtered accordingly. What I want is My plugin should ...
1
vote
2answers
62 views

Representation of precipitation data

I have an excel sheet of precipitation data of each month of some districts. I have also the shapefiles of these districts. How can I represent this data in these shapefiles.
1
vote
1answer
46 views

QGIS change raster tiles properties at once

I have a set of several raster tiles and I need to change the properties of each one, by setting up a transparency for instance. I have found no other solution but changing properties of each one at a ...
2
votes
0answers
25 views

Is it possible to enter start/stop points non-interactively in Road Graph plugin?

I need to find the shortest paths in a network of roads for many pairs of start/stop points. The Road Graph plugin in qgis allows me to interactively select a starting and ending point on a map, but ...
2
votes
1answer
1k views

QGIS moving the layer/all features using Vector Affine Transformation

I'm using QGIS to analyse some flight tracks which were produced using a different software. Now when they are on QGIS the reference point of everything is on 0,0 which is the aerodrome reference ...
-1
votes
1answer
568 views

viewshed analysis QGIS

I'm trying to make a viewshed complemented Quamtun viewshed analysis in GIS, someone managed to do it? in my case not allow me to finish the process skips a misconception among other things tells me ...
1
vote
0answers
159 views

Representation of road networks at junctions when line width is varying with attribute

I have a road network and for every road segment the average number of daily traffic. I need to draw a map where the line width for each road segment is proportional to the daily traffic. I can do ...
0
votes
1answer
96 views

ImportError: libqgis_core.so.2.9.0: cannot open shared object file: No such file or directory

I installed qgis in debian linux and I want to run a standalone app in python. So I import qgis.core and qgis.gui in this app. But it gives me an error: ImportError: libqgis_core.so.2.9.0: cannot ...
1
vote
1answer
128 views

How to create Spatial Reference System in QGIS?

I have some Attribute and the coordinate and the coordinate reference system. I want to create a DBmanagamet form my spatial data. To do that I want to create one table with name Spa_ref_sys, but I ...
1
vote
1answer
282 views

setting SAGA folder for QGIS with OS X macports install

I am trying to get the toolbox to work in QGIS 2.6, but I keep getting an error message that SAGA is not properly configured. After much digging, I finally found I can set the SAGA folder in ...
0
votes
0answers
57 views

How to decide when flood started depending on the rainfall data?

I created a raster with the point values (mm) of rainfall data by interpolation in the raster menu. So I have a raster rainfall data and a DEM. With this rainfall data and a DEM corresponding to ...
2
votes
2answers
330 views

How to use attribute data for legend labeling?

For features in a map it is possible to stuck data from the attribute table together and get a data driven label. I try to do this for my legend labels. I want to combine values from my attribute ...
0
votes
1answer
124 views

How to cut a raster into smaller, equal area parts?

I have a large raster file that I need to cut into smaller parts. I already have a polygon shapefile that has the smaller parts that I want to use as an index. The reason for this is that end users ...
0
votes
0answers
24 views

How to manually apply permanent ArcGis Stretch images filters out of box?

I usually use Arcgis image stretch filters for my images to make them sharpen or to highlight certain elements of a raster like this: Version without filters: Version with filter: How can i apply ...
0
votes
1answer
42 views

“No-break space” for labels

My map has labels, which usually should break after the 14th character using "wordwrap": wordwrap(name,14) But sometimes I need to suppress the wraping. So I need to use a "No-break space" - is ...
2
votes
1answer
100 views

How to place labels on multi-geometries in QGIS?

I need to put a label value on each geometry, so I do not need to locate the label on the (or near to) centroid. I use QGIS 2.6 on windows 7 Most ot the records has only one geometry linked to, but ...
1
vote
1answer
160 views

Qgis 2.8 problem with font size

I'm using Debian 7 and yesterday i had an update of Qgis 2.8. Since then I can't change font size and type, at labeling and print composer, whatever i pick it returns to the default "Free sans" size ...
2
votes
1answer
123 views

PyQGIS load dxf file as a vector layer

Can somebody help me with loading a dxf file as a vector layer with PyQGIS? Is QgsDataSourceURI an option? I've tried it with this code, but it didn't work. fitxer="/tmp/prova.dxf" uri = ...
1
vote
0answers
61 views

Trying to split a complex shapefile by australian states

Im trying to work with a 1:1 mill scale shapefile of the geology of Australia. When the whole lot is loaded in to QGIS (over 200,000 polygons) it will freeze and go to slow to work with. Ideally i ...