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

learn more… | top users | synonyms

7
votes
3answers
11k views

Viewing .las format LIDAR data in QGIS?

Is there an easy path to visualizing this LIDAR data in QGIS? I have some USGS LIDAR data in (.las) format downloaded from http://lidar.cr.usgs.gov/ . This means I have both the (.las) and metadata ...
0
votes
0answers
6 views

QGIS Qt Designer set current date and time in mask

I have created an input mask for QGIS using the Qt Designer. Everything works fine but I have a small issue with the date, the time and the date/time edit widget. Is there any way to display the ...
8
votes
1answer
534 views

Is it possible to have dynamic layer names in QGIS project?

I have a QGIS project with layers, based on PostGIS SQL queries that use current date. Since the data in the database changes, these queries return different data every new day. Is it possible to ...
1
vote
2answers
18 views

QGIS 2.12/14 Add GPS Point missing geography

I am trying to use the integrated GPS module from QGIS to add data points to a shapefile while in the field. I managed to get the connection between qgis and the gps working and my location is shown ...
0
votes
0answers
16 views

QGIS Mean coordinates, very slow?

I use Mean coordinates tool for a layer where the UID is a string and weights are real numbers. I find it very slow (literally hanging QGIS for few minutes) when processing datasets of more than few ...
2
votes
1answer
33 views

How to create a custom coordinate grid in the QGIS 2.14.2?

I want to create a custom grid different from latitude / longitude, with letters and numbers on the axes. X = A, B, C, D, D, ... Y = 1, 2, 3, 4, 5, ... A B C D E 1 2 3 A B C D E I also ...
0
votes
0answers
13 views

Qgis map is disfunctional

Of recent I have this problem with Qgis 2.14 that my map composer won't produce a map of my project but instead it goes all blank. I even used 2.12 and even after uninstall/install the problem still ...
2
votes
1answer
628 views

Visualizing a LiDAR point cloud in 3D with GRASS?

I'm new with QGIS and GRASS so I'm sorry if there is a straightforward answer for this question but I can't seem to get it done. I've imported a point cloud into QGIS from a datafile. Now I'd like to ...
1
vote
1answer
46 views

Importing Data with CSV

I am wondering what I would need to do in order to import a CSV file and then combined that with an existing layer. I would like to know which boxes I need to check in order to make this combine with ...
2
votes
1answer
25 views

Dynamic Linear Referencing of events in QGIS from Excel or CSV using virtual layer

I have a PostGIS table with a geometry type LINESTRING M to represent routes. Here is the table specification: CREATE TABLE routes ( fid serial PRIMARY KEY, r_name text NOT NULL, geom ...
0
votes
1answer
23 views

Digitizing jpeg image or georeferencing it first?

I'm a new learner when it comes to QGIS. I have a jpeg image and I want to convert it into a shapefile. The problem is when I polygnized it, the resulting image is inverted. So i decided to just ...
2
votes
0answers
29 views

QGIS canvas refresh & rendering control from plugin?

Plugin Description I have been working on a plugin which essentially doing the same as "GPS information" live tracking but with capability of displaying two GPS streams. I am comparing streams and ...
0
votes
1answer
31 views

QGIS Processing Toolbox not valid

I have a 64 bit windows 10 computer with ArcGis 10.2.2 Installed. I just downloaded QGIS the newest version 2.14 64 bit. it downloads but the processing toolbox throws this error Couldn't load ...
3
votes
2answers
47 views

Semi, third, quarter circle and other compound style symbols in QGIS?

I think I used quarter (and other) circles in QGIS in the past. But it might be as well that it was only in different software. Anyway now I am not able to find in symbols any option for compound ...
3
votes
1answer
87 views

QGIS Select overlapped feature

I have points that are not equal but the distance between them is so small that it can't be seen even at scale 200k:1. I calculated the distance between these points and add it as attribute. Now I ...
3
votes
1answer
499 views

Export several files at the same time in QGIS

I have a lot of .TAB files open in QGIS and I want to save them to .SHP so I can work with them in ArcMap. Is there a way to save/export all these files at the same time or do I really have to "save ...
0
votes
1answer
219 views

Automatically split KML into point, line and polygon SHPs?

I have a lot of KMLs that include points, lines and polygons together, is there a way to automatically parse them into separate shapefiles (one for point, one for line, one for polygon) in QGIS or ...
2
votes
1answer
974 views

Can QGIS open a SDF file created by HEC RAS?

I used the "export GIS data" option in HEC RAS and got a SDF file. Is it possible to open it in QGIS?
2
votes
1answer
67 views

Customising QGIS Map Composer?

I am using QGIS for map making , I am adding multiple vector and raster layers and then finally for map making I am moving to the map composer. When I am exporting the map from Map composer , I want ...
0
votes
1answer
41 views

In Postgres how to create columns with geometry?

I have point data stored in the postgis server and I need to create a new table with their geometry values. How can I extract their coordinates and translate them into a table. Something like: ...
0
votes
0answers
15 views

Adjusting labels in for stationing

How do I update labels for stationing? I am using the "Station Lines" plug in which is great, but I need the labels to read 01+00, 02+00.... as opposed to 1,2..... Also, can I start this labeling ...
0
votes
0answers
66 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 ...
4
votes
1answer
202 views

Is it possible to export a QGIS project to Mapnik XML?

Is it possible to export a QGIS project to Mapnik xml? I'm using QGIS 2.4 and Quantumnik does not seem to work with that version.
0
votes
1answer
296 views

Crop one shape file using another shape file in QGIS

In QGIS 2.0.1, is there a way to automatically slice up one shape file and export it as multiple files using polygons defined in another shape file? I have a detailed shape file that categorizes the ...
0
votes
0answers
9 views

convert SHP to DGN with ogr2ogr

I want to convert may shp layers into one DGN file using ogr2ogr (qgis). When I use this tool, I can only select one layer to convert it :/ my problem is I don't know how to select all my three layers ...
1
vote
0answers
11 views

Colorramp displays gray

I've been using QGIS for quite some time now, but lately something weird is happening to the colorramp I want to display on my raster(lidar)-files. The rasterfiles just have a grayscale instead of ...
1
vote
1answer
60 views

Adjust grid points to map

I'm trying to generate equidistant points on a map, I used QGis to do it, but the problem is that some points are out of the map area. I'd like to consider only the points inside the map. This is an ...
2
votes
2answers
42 views

using PyQGIS to subsample a region of a raster layer's pixel data

I am having trouble sampling multiple pixels from a raster layer at oe time. If I want to sample pixel data from a layer at a particular coordinate I can write. ident = ...
1
vote
0answers
27 views

Qgis python: no interaction with Map Canvas

I've created a simple python script to load and show two layers and zoom to the first one. It looks like the script doesn't run the last 4 lines after I uncomment'print lyr1'. Anyway the map canvas is ...
3
votes
1answer
53 views

Selection by adjacent polygon features

I have a large polygon shapefile with lots of features from a model output, I need to remove anomalous features which are joined by a single vertex and part of a cluster of two. (example highlighted ...
3
votes
0answers
33 views

Create an optimised path between nodes avoiding polygons entities

I have a point shapefile representing seaports. I have the linear cost of shipping for every seaport pairing (specific shipping cost to go from one point to another point). I want to find a way of ...
1
vote
3answers
96 views

How to add a pie chart based on all (or some) features in a layer?

I have a vector layer in a QGIS project which has about 60 items with various attributes, including a check for if an item is complete. I am trying to get a pie chart showing the percentage of the ...
1
vote
2answers
72 views

How to split a large point vector layer in QGIS?

I need to split my shapefiles into much smaller pieces so that I can upload them onto the Postgis server. Shapefiles have DBF files with 14 Go (1,000,000 rows) and I need them to be under 2 Go. I've ...
1
vote
1answer
36 views

Why the street label is not showing in a feature in QGIS 2.14.2?

Why this street label is not visible even with zoom? It has 'name' in it... Here_qgis2.14.2_file
0
votes
3answers
960 views

How to install QGIS with OpenGeo Suite on Ubuntu

I was wondering how should one install QGIS after installing OpenGeo Suite on Ubuntu Linux? I installed OpenGeo 4.1 on Ubuntu 12.04 following the instructions on the official website ...
3
votes
3answers
116 views

Is there a way of labeling the number of points with the same coordinates?

After reading through the following question (which is kinda related but not quite what I need): How can I show points on the same coordinate as e.g. a bigger symbol in QGIS? I found out that there ...
5
votes
1answer
67 views

Keep UI Settings for a QGIS plugin

I'm writing a plugin that interacts with external software (hydrological models). One of the dialogs has a lot of entries (parameters to pass to the hydrological software). Once the user has set up ...
5
votes
2answers
743 views

How to access the road graph plugin in python?

I am developing a few scripts in Python for QGIS 1.8 to automate some geo-tasks and one of them would be to calculate the shortest distance from a hospital to each building in a town. I would like to ...
2
votes
2answers
68 views

Slope Analysis in QGIS

I am New to QGIS, I have the Contour Information in the form of Line Features, How can I do a Slope Analysis. Is it Possbile at all ? For Reference I am attaching the Image. the lines in the ...
1
vote
1answer
42 views

Where to use the shp2pgsql commands?

I need to upload some very large tables (over 10Gb) into Postgis so I actually found this link What is the best hack for importing large datasets into PostGIS? The DB manager is far too slow and only ...
1
vote
0answers
11 views

Feature Labels wrong with GeoJSON data source

EDIT: I found out that the attribute table changes when zooming, my GeoJSON output does not change however. I am working on a QGIS project where I've imported points as a GeoJSON data source from a ...
1
vote
0answers
21 views

Unsupported Source

If I try to save a raster files from a WMS once saved tells me that the source is not supported, "Data Source not supported: /Users/beatriceluise/Desktop/wms/Senza titolo.tif is a raster data source ...
2
votes
3answers
56 views

Digitizing Tools error in QGIS

I receive this message: Digitizing Tools: Amend Line is disabled because layer CRS and project CRS do not match. If I set the CRS of the layer the same as the project CRS (W84 Pseudo Mercator) is ...
4
votes
1answer
2k views

Why are the Google basemaps no longer appearing in QGIS?

I had done a few projects using Google Physical/Streets as basemaps but now when I re-open those projects all layers appear except for the google basemap (other layers include .kml). I had ...
1
vote
1answer
45 views

Creating a polyline with a specified slope

I would like to create a road (polyline) starting from a point, with a specified slope, until reaching the top of a hill (or going out of the DTM Raster). The dowstream slope of the DTM must always ...
1
vote
2answers
36 views

QGIS count how many lines cross a polygon

In QGIS I create some lines that cross three polygons. By using intersection, it will create a new shape file that gives me as a result the lines inside the three polygons. If I open the attribute of ...
1
vote
2answers
33 views

Backup GIS data on postgis database from pgadmin3

I am using a postgis database with qgis and managing it with pgadmin3 I have already investigated the backup/restore options within pgadmin 3 and done one test run on one database I am wondering if ...
1
vote
0answers
16 views

QGIS not loading default layer style from PostgreSQL database on startup

I have saved a vector layer style to my PostgreSQL database source. I then amended the layer_styles table record for the relevant layer by editing the styleqml field (just changed the outline_width ...
1
vote
1answer
38 views

QGIS line cross a polygon

In QGIS I create a line that crosses a polygon twice. By using intersection, it will create a new shape file that gives me as a result two visible lines (the polygon cut the line). With geometry ...
1
vote
2answers
39 views

QGIS place labels next to the beggining or ending points of Linestrings but above the Linestring

I've got a Linestrings layer. Each Linestring has among other fields, these ones: id ENTRY EXIT 1 S1 E2 2 S1 E3 3 S1 E3 4 S1 E3 5 S1 E3 6 S1 E1 7 ...