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

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4
votes
1answer
243 views

Why can't I copy values from a virtual field to a non-virtual field using PyQGIS?

Using the python console, I am trying to copy values from a virtual field into another non-virtual field. Both fields are integer types but I get NULL in the non-virtual field. I followed the answer ...
1
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0answers
88 views

Using GPS to field walk through a LiDAR scene

I am doing field surveying for archaeology using Lidar. If I attached a USB GPS to my laptop would it be possible to track where I am "in real time" on the Lidar as I am field walking? I'm wanting to ...
2
votes
0answers
29 views

Delineate new political boundary in dataset

In the political area I'm working on, there has been a recent formation of a new city, legitimized with government plebiscites and resolutions etc. Geographically speaking, it's still the same land ...
3
votes
2answers
325 views

Understand QGIS errors when importing .csv file

I am trying to import a .csv file as a layer in QGIS and keep getting a number of errors that I don't understand. Is there any documentation of QGIS errors available? Or can you point me towards a ...
1
vote
1answer
252 views

Cannot install “Processing” plugin on MacOS + QGIS 2.9.3, fresh install

I have just installed a new MacBook Pro and QGIS, everything is fine but this strange error if I try updating or reinstalling the "Processing" plugin. The plugin is broken. Python said: cannot ...
1
vote
1answer
97 views

Joining Parcel/Building Attributes Based on Coordinates

GIS noob here: I downloaded a building footprint shape file for a city and imported it as a vector layer in QGIS. I was hoping to see street address information in the attribute table, but there was ...
2
votes
0answers
133 views

How to make a model with more than 2 input layers for buffering and merging?

Would it be possible to add more inputs to Buffer and Merge? From what I can see there is a limit of two input layers per both. As far as I know this is possible in ArcGIS's Model Builder but from the ...
3
votes
1answer
153 views

How to change font color in one column of attribute table in Composer reports?

How do you change the font color in just one column of the attribute table included in QGIS's Composer? I would like to have the numbers listed in color red just for one column out of four columns in ...
2
votes
2answers
511 views

How to create a line between a point and nearest neighbour using python (template included)

I have 2 shapefiles - one is a series of points, the other is a polyline. I want to draw a straight line between each point to the nearest point on the polyline. This question has already been asked ...
1
vote
1answer
293 views

Adding point layer in QGIS from SQL Server failing

I just downloaded QGIS a few days ago (version 2.8.2-Wien) but I am not able to get it to work as I thought it would. I tried pulling in spatial data from sql server (a "geometry" column containing ...
1
vote
1answer
145 views

Problem with Memory storage type in PyQGIS when updating with auto form

I have a layer of "Memory storage" type (Memory provider) which I created with Python. When editing=on and updating values using the attribute table interactively everything works as expected, i.e. ...
1
vote
1answer
310 views

Combining multiple overlapping rasters - retain maximum value?

I have 40 overlapping raster grids (derived from flood modelling software) that I want to combine in such a way so as to retain only the maximum value in any of the given rasters at each grid location,...
2
votes
1answer
678 views

How Can I Create a Tin from Elevation Points in QGIS

I have a shapefile of points with values that represent elevation at the given point. I know that I can create a TIN from these points, but the fields in the TIN do not represent the elevation. Rather,...
1
vote
0answers
20 views

Does fixed classes exist in QGIS?

I'd like to create several images of voronois polygons in QGIS; each images having differents values joined to the voronois. I tried to load a qml style with the values I want to keep (8 classes : 0>...
1
vote
0answers
21 views

Overlapping polygons: how to sum attribute values for areas where multiple polgons overlap [duplicate]

I have what seems to be a fairly simple problem but I cannot find a solution. Any help would be much appreciated. I am working in QGIS 2.8.1. I have a shapefile of polygons, each of which has a ...
0
votes
1answer
92 views

Combine several rasters in QGIS

I have a problem combining several rasters into one big raster. Particular annoying is, that I had this problem once before and solved it, but I can't remember how. Unfortunately the other ...
0
votes
1answer
191 views

QGIS DB Manager - load as new layer not loading

After successfully running an SQL query on two tables and some results in 3 columns, I would really like to be able to display it in the canvas. Apparently, that function is not doing anything, not ...
1
vote
0answers
116 views

Editing data in QGIS Server via WFS in AutoCAD Map (2015)

I have a QGIS Server up and running. I can consult my layers using WMS protocol and edit them using WFS protocol in QGIS or lizmap web client for example, but I am not able to make it work in AutoCAD ...
4
votes
1answer
490 views

QGIS Join Attributes by Location not working from Python script

I have a shapefile with points, and a shapefile with polygons. I want to sum the attribute value of all points that are within a certain polygon, and I'd like to do this for each polygon in my dataset....
2
votes
1answer
49 views

What's the syntax to skip optional saga:catchmentareaparallel parameters?

In PyQGis, I want to use saga:catchmentareaparallel algorithm, in the parameters there is an optional arguments, and I don't want to use them, what is the value should i put on the argument? i try to ...
2
votes
0answers
81 views

Relative path in layer styles in spatialite

is there way to store default style in relative path in spatialite??it has layer styles table,and a column 'f_table_catalog'.and in this column pathes are absolute,In Qgis project options i set ...
1
vote
0answers
63 views

Algorithm for re-numbering duplicate feature IDs based on distance along line (PyQGIS and QGIS 2.8)

I've got something working for QGIS 2.8 using Python 2.7 on Windows 7, but I am missing an important part of the puzzle. I'm trying to develop an algorithm to number homes. I've now come to a point ...
1
vote
2answers
99 views

pyQGIS version of the arcgis tool dice

I'm using QGIS and I have some large features that need to be diced up into features with less vertices. If I were using arcGIS I could use the dice tool If I were only interested in lines I could ...
1
vote
1answer
44 views

How to convert GOES-R (15) IR image from gray-scale to brightness temprature

How do I convert satellite IR images taken by GOES-R (15) from gray-scale to brightness temperature? We can download the IR satellite images, and read its RGBA values. But how can we convert this RGBA ...
1
vote
0answers
54 views

How can I show a trip on a map, color-coded by how long the trip actually took?

I have a series of origin and destination addresses in a spreadsheet, with start times and arrival times for each. I'd like to plot them on a map, with a line between each origin and destination, ...
2
votes
1answer
132 views

How to clip a raster by extent using Processing from the Python console?

I want to clip a raster by extent in QGIS with the python console. Here is the description given in the documentation. You have to use the following input parameter: Input layer Nodata value (...
0
votes
1answer
75 views

Land cover modifications in different time periods

I have several shapefiles which contain buildings built in different periods from 1948 to 2013. My question is how could I see which buildings for example in were built 1948 but are missing in later ...
2
votes
1answer
332 views

QGIS Viewshed Analysis Plugin

Does anyoe have a link to or know of a list of raster formats the above tool can work with? I'm on QGIS 2.8 using the latest version of the plugin. I've tried a couple of different raster types and ...
1
vote
0answers
50 views

Opening *.lyr file in QGIS without access to ArcGIS for Desktop? [duplicate]

Is there a way to open a *.lyr file in QGIS without using ArcGIS for Desktop? I have no access to ArcGIS, so the solution explained in Adding Layerfiles (.lyr) to QGIS? is not an option. I have a *....
2
votes
2answers
460 views

Heatmap using Kernel density estimation

I have been trying to generate heatmap using kernel density estimation from python console in QGIS. This is command i'm using: processing.runandload("saga:kerneldensityestimation", "D:/test/Towns....
3
votes
1answer
122 views

How to add my own GRASS algorithms to Processing?

I need to use algorithm r.bioclimatic from GRASS in QGIS but I see that this algorithm don't exist in Processing Toolbox. A search a way of add this algorithm to Processing and in GRASS and Sextante ...
2
votes
1answer
849 views

Postcodes mapping

I am new to GIS. I have a list of postcodes and I have to make a map, basically to show distance from a specific area. Concentric ring pull type of map. I don't know how to get my postcodes into a ...
1
vote
0answers
31 views

QGIS hide the field in the feature properties form if the field's value is empty

When clicking on a feature with the tool and obtaining its properties, in the form that is shown, I would like to view only the fields that are filled (not empty). In some layers I have 50 fields but ...
2
votes
1answer
106 views

How to define map extents based on a feature's geometry?

There is a polygon geometry in my QGIS project which represents the extents of my map. Does anybody know how to use the data defined override to get the X/Y min and X/Y max coordinates of the polygon ...
1
vote
2answers
266 views

How can I import open street map power grid data into QGIS?

I wanted to download power grid network of Cologne city from following url http://www.flosm.de/en/Power-Grid.html But I could only download in jpg format. I wanted to import this in GIS as vector (*....
1
vote
1answer
127 views

How to install QGIS 1.8 plugin QGIS2KML?

I am trying to download QGIS2KML plugin. I went to Plugins → Fetch Python Plugins in the Repositories tab and pasted the url. It claimed that it was successfully downloaded, however, QGIS2KML was ...
0
votes
0answers
107 views

Use QGIS and Qt dialog forms

I have a QGIS project where there are plots with a attributes like name of the owner, address of the owner, cultivate, and so on. This plots are read from a PostGIS database. The future users of this ...
0
votes
2answers
334 views

To select the range of values using Raster calculator in QGIS

I am working on a project where, I need to give ratings for the range of values. I have the following ratings index ratings 0 to 4 4 5 to 8 3 9 to 11 2 12 to 15 1 I am ...
1
vote
0answers
77 views

Matching/snapping two shapefiles using node and snapping tools

I am trying to edit my shapefiles through QGIS 2.6.1 Brighton. I used the node tools to snap the necessary nodes to eliminate spaces between two shapefiles. However, while doing it I noticed that an ...
1
vote
1answer
223 views

Heatmap failing in QGIS (2.8.2-Wien)

I am super new to QGIS so I may be doing something really dumb, but it doesn't seem to work to create a heatmap in QGIS Desktop 2.8.2 (just downloaded this yesterday so I think it is the most current ...
1
vote
0answers
18 views

QGIS - “Error Entry Point Not Found” when launching QGIS 1.8 [duplicate]

I am trying to download QGIS 1.8 on my windows operating system. When I tried to launch QGIS 1.8 a dialog box appears, preventing me from launching the software. This is the error that is generated: ...
1
vote
3answers
289 views

How to search within a string to extract data from OSM other_tags?

I am working with OSM data in QGIS and I often need to query items in the other tags field. When I download the data using the OSM download plugin the other tags come in one field so are not easy to ...
0
votes
1answer
91 views

Add Attributes from polyline / polygon to polyline layer by best coverage

I have two polyline layers in QGIS containing information on a network and I need to transfer some attributes from the second layer to the master layer. Unfortunately their geometries are not equal, ...
2
votes
0answers
94 views

QGIS not interacting with iface from python class

So I'm working on something where i need to use threads from python console of QGIS. The following line of code adds layer successfully iface.addVectorLayer("D:\ArcGIS Misc\Atlas\points.shp", 'Points'...
3
votes
1answer
76 views

How to access CRS of shapefile in standalone script?

I'm trying to access the CRS of a layer and use this to create a grid. I followed the answer in this post which works great in QGIS but I would like it to work in a standalone script. Here is a ...
1
vote
0answers
65 views

How to “output to a raster file” in a standalone app based on a composition?

In a standalone app I want to create a print composer with the map, a legend and a scale bar. I try with different codes but without success. I search in several foruns but I didn't find an answer. ...
0
votes
3answers
241 views

GRASS convert raster to points

I have tried to convert a raster to points using this syntax: r.to.vect input=g_kelowna_merged@kelowna_mapset output=g_kelowna_points feature=point I have tried using the GRASS interface in QGIS and ...
2
votes
1answer
254 views

PyQGIS: how to delete layer from TOC when attribute table is closed?

I'm developing plugin where I want to be able to edit non-spatial table inside the attribute table dialogue. As it seems that the only way to do so is to add this table to the TOC first, I do so. But ...
0
votes
0answers
39 views

Total area of polygons over latitudes

I'd like to calculate the total area of several polygons along a north-south axis. A bit like this http://www.closr.it/canvas/1307/#/spot There is a similar question with R : Spatial graphing, ...
4
votes
1answer
165 views

Is there a good way to use Spatialite in QGIS?

I am somewhat disheartened by my experience with Spatialite databases in QGIS. In theory, it could be what personal geodatabases are for ArcGIS: a consolidated, portable format that keeps projects ...