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

learn more… | top users | synonyms

2
votes
0answers
27 views

not all OSM polygons downloading in QGIS

I have been trying to download all of the polygons contained within OSM for a particular extent of the city. When I do this through > Vector > OpenStreetMap > Download Data, however, many polygons ...
1
vote
0answers
23 views

Using “Ruled Based Render” to display labels without the marker with python in QGIS

I'm writing a script to load and manipulate some shapefiles. Unlike my previous question I now need to display labels only on certain zoom levels. My usual result is that the previous formatting gets ...
2
votes
1answer
33 views

Export google satallite raster in QGIS 2.12- problem

When I import aerial raster from Google satellite, using the OpenLayers plugin the raster is located in the right place. But when I export it the raster isn't located in the right place: I ...
1
vote
2answers
67 views

QGIS 2.14 Essen Scale Setting Problem

The scale of the canvas plot shows in the status bar as everyone knows. However If I want to change the scale it refuses to work properly. This occurs whether I select a scale from the drop-down menu ...
1
vote
0answers
30 views

QGIS 2.14 atlas legend not resizing

I have an atlas in QGIS 2.14 with a filtered legend whose position is anchored at the bottom right corner. When viewing atlas pages individually within the print composer, the legend size increases ...
2
votes
1answer
59 views

Cost Distance Map in QGIS

My question is very similar to Cost Distance Analyst In QGIS? However, I'm looking for a means by which I can create a raster displaying the cumulative cost of each pixel to a specified destination ...
1
vote
0answers
27 views

qgis snaps to outside instead of boundary

I have polygon layers that I need to be covered by other polygon layers, and many of my inner layers have a vertex on the border of an outer layer or in some cases they share an edge. Both ST_Covers ...
3
votes
1answer
31 views

Positional join with multiple overlaying geometries, each containing a different attribute

I can't find any documentation on how a spatial join in QGIS is working on the following situation: An area layer is being spatially joined with a polyline layer in order to compare attributes of ...
1
vote
1answer
52 views

Installing and using ArcGIS REST API Connector plug-in?

I downloaded this plug-in http://plugins.qgis.org/plugins/connector/ from the plugins link at QGIS.org and it unzipped into a folder entitled "connector" in my "downloads" folder (running Mac ...
1
vote
0answers
26 views

Densification of Point Layer to get smaller Voronoi Areas

I'd like to densify a point layer to get a better spatial distribution. With "better" I mean homogeneous distributed. If I had to quantified my improvement, I would calculate the voronoi diagram and ...
1
vote
0answers
36 views

Python error in Qgis 2.14.0

I'm trying to build virtual raster (catalog) following instructions from the documentation in QGIS.. It appears the following error in python code: 2016-04-17T12:13:07 1 Traceback (most recent call ...
1
vote
0answers
32 views

Problem of resolution - conversion vector (points) to raster QGIS

I continue the following of the first problem : How to convert points to a raster in QGIS (rasterize does not show z field)? My goal is to create outlines watershed at a resolution of 5 min (10 km) ...
1
vote
1answer
33 views

Reverse geocoding with QGIS

I've downloaded us region boundaries from US census bureau, which is a .zip file. I can open to view the file with QGis as follows (4 regions + Alaska): Now I have a dataset containing a lot of data ...
1
vote
0answers
16 views

Delaunay Triangulation on labeled data

I have a table with locations and labeled data and I need to apply Delaunay Triangulation on specific labeled rows. For example, I have some locations labeled as schools, hostels, gardens, ... and I ...
1
vote
0answers
42 views

Slow performance clipping raster with GDAL

I have a few large LiDAR DEMs that I want to merge. Each DEM has some glitches around the borders which need to be removed in order to get a seamless final product. I manually traced around each DEM ...
2
votes
1answer
37 views

QGIS Join table with shp file. Get Null Values on the join fields

If my problem is that my ID types are not the same, I need help in addressing that. I started with an excel file, I read that on a mac to I need to save that as a Windows comma Separated file. I ...
-3
votes
0answers
44 views

I have opened a file in QGIS from OS data and want to change the colour of some tiles

When I download OS data, onto QGIS desktop 2.14.0, some of the tiles are black and are too highlighted, I want to change this colour, when I righthand click the tiles and go onto the layer button, the ...
3
votes
2answers
62 views

How to group by attributes and give unique categories in QGIS?

I have features and each of them has an attribute about what it is. In my case, I have points representing trees and each tree has its species name as an attribute. I would like to group them by ...
2
votes
2answers
175 views

How to iterate over layers and export them as PNG images with PyQGIS in a standalone script

I would like to export specific layers as a png from a QGIS .qgs map. From the table of contents the script would first export the "boundary, climits, and Div1_Irrig_1956_0" layers as one png. The ...
1
vote
0answers
25 views

QGIS: Release file lock on file used in a processing algorithm at the end of script

I am using runalg (qgis:joinattributesbylocation) on two QgsVectorLayer objects. At the end of my script I'm trying to delete all the files created during the script. I can delete everything except ...
2
votes
0answers
28 views

Strange behavior for QgsProject snapping options - Python QGIS 2.8

I have some strange behavior regarding the snapping options function setSnapSettingsForLayer in the QgsProject class. I am setting the snapping parameters in the following way: ...
1
vote
0answers
18 views

Deliminated layer cuts off imported spreadsheet at row 20

Platform: Mac, OS: Mavericks, Qgis: 2.14 Essen Exporting spread sheet from Excel as Windows .csv. No problem publishing points to map except that import will only process 20 of 23 row entries on ...
-4
votes
0answers
30 views

Path used to save file

on another post, someone gave me some code to save a raster to .tif, but I was never able to save the files, and the person who shared the code said it worked for him. I noticed that in the path I ...
1
vote
0answers
24 views

How to restrict only a Layer Group instead of giving the whole service when loading a WMS on qgis?

I created a workspace, a store and some layers on GeoServer. Then I created a layer group and added a few layers. When I try to load a specific layer on QGIS I use the following URL: ...
2
votes
1answer
48 views

Can I control what field comes up first in the Identify Results window in QGIS?

My shapefile has 20 fields in the attribute table. When I click "Identify results", the third text field (Welsh_Name) comes up first. Is it possible to change which field comes up first (at the top ...
2
votes
2answers
71 views

How to convert points to a raster in QGIS (rasterize does not show z field)?

How to convert my points into a raster along the z attribute and a resolution of 5 minutes or 10 km First I import the data as a .txt file and then I convert to a vector (shapefile). then I do: ...
2
votes
1answer
72 views

Why do layers with different CRS overlap fine but cannot be merged by location?

Perhaps someone could clear this up for me? I have a shapfile with the CRS Selected CRS (EPSG:29902, TM65 / Irish Grid) I also have a number of XY points which take the CRS, Selected CRS (EPSG:4326, ...
1
vote
0answers
23 views

How to interpolate (ordinary kriging) large files with QGIS processing

I'm using the Saga ordinary kriging tool as apart of different processing models. The biggest issue I have is the very slow performance. My point shape files have mostly more than 200.00 points (some ...
0
votes
0answers
15 views

How do I create a set of maps using QGIS atlas that has two maps in the print composer window?

I'm trying to use atlas to produce a set of 8 maps. I want 2 maps on each page, each showing different areas sequentially. So the output would have 4 pages, with maps 1 & 2 on the 1st page, then 3 ...
2
votes
0answers
46 views

Script to Compute the river slope with correct DEM elevations? [closed]

I know this topic has been discussed before in this forum , I read all the suggestions but I think I still have the same issue. Working with QGIS, I'm supposed to compute the slope of river channels ...
2
votes
1answer
48 views

How to automatically reload a layer every 30 seconds?

I need to 'triggerRepaint()' a rasterLayer every 30 seconds, it's possible do it in QGIS? perhaps, a background process ui in python? create a watcher in python like QFileSystemWatcher
0
votes
0answers
11 views

Can't get new layer from QgsGeometryAnalyzer [duplicate]

I have this user's problem as well. When I click "RUN" in the Text Editor in QGIS, nothing appears, and I haven't got any errors. It is a very symbply class but surprisingly, I can't get any result. ...
1
vote
1answer
30 views

Problem with QGIS Layer view / Layer Properties view

If I open the Layer Properties of my project all is fine. All styles shown in there stylegroups like shown in the following screenshot sample But in the Layerview the groups gone. All styles of an ...
3
votes
2answers
66 views

How to get lines into polygons?

I have to create a map with the land register of a place. The data that I already have is unfortunately built out of lines and not polygons. Is there a possibility to create polygons? I already ...
3
votes
1answer
66 views

Export raster layer in python to specific folder

I am trying to export existing raster layers as tif files. I just want to avoid saving each raster manually. this is the code I am trying to use, but it doesn't seem to work: from PyQt4.QtCore import ...
2
votes
2answers
38 views

Using SCP image classification to find swimming pools?

i'm currently trying to use the scp image classification plugin to find swimming pools in an aerial image. It is just an RGB image as if it had infra red this'd be a lot easier. Does anyone know how ...
1
vote
0answers
33 views

How to calculate a Label Point for a (multi)polygon [duplicate]

ESRI software has a concept of a 'label point' for a (multi)polygon. It is like the centroid, except it is guaranteed to be within the (multi)polygon. Like for a U-shaped polygon, the label point is ...
1
vote
0answers
17 views

Converting .shp to wkb after v.clean

I've been trying to get to through this by reading manuals, but I can't seem to understand what I'm doing. I have source data with overlaps that exist in a table with associated WKBs(SRID 4326). I ...
2
votes
1answer
45 views

Displaying layer after using QgsGeometryAnalyser?

I have already discovered this class, but I am confused. If I am doing a analysis on the current layer, I don't know why it is not displaying on the map. lyr =iface.mapCanvas() layer = ...
2
votes
0answers
14 views

QGIS Qtiles from EPSG 3395

I am having issues while converting my layer from 4326 to 3395. My Qtiles does not make tiles. I have a source mapinfo in 4326 with long, lat pairs. My goal is to show this on a maps.yandex (3395 ...
3
votes
1answer
63 views

Big datasets in QGIS

I'm working with large PostGIS tables in QGIS but really only need to do simple visualization and editing the attributes (like change road names, speed limits, etc). The most processing I need to do ...
2
votes
2answers
53 views

How to identify feature from multiple layers in QGIS?

I have recently migrated from ArcGIS to QGIS. Is there any way to identify a feature having multiple layers? I am currently working with about 400 shape files and need to know which is the one I'm ...
1
vote
1answer
30 views

How do I launch multiple instances of QGIS (Mac)?

Often I need to work on two qgis projects at the same time. How can I launch two separate instances of QGIS?
0
votes
0answers
11 views

Trace the outline of a point cloud [duplicate]

I want to know if there is a plugin in QGIS, which will allow me to draw the outline a point cloud. I know there Points2One the plugin, but it makes an outline with all points, even with the data ...
2
votes
1answer
35 views

QGIS filter on date value

I would like to filter on a date value (show only attributes with a date later than 1-1-2000 for example). The field is of QDate type. But doing so I get the message: "Type mismatch or improper type ...
1
vote
1answer
38 views

Merging and splitting raster files in QGIS

I have four .HGT topography tiles (tile1,tile2,tile3,tile4 in the photo below). They are in geographic coordinate system. I would like to merge those four tiles, and then from that merged raster layer ...
2
votes
2answers
65 views

Will upgrading my RAM and Processor speed up functions on QGIS Desktop 2.12.0?

I am using QGIS 2.12.0- Lyon (64-bit) at work and have been finding with especially large amounts of data (many vector layers) that all processes on the system have been running slower. I am running ...
2
votes
1answer
37 views

How can I subtract one (very very large) set of features from another?

I'm trying to subtract a very large set of features (water areas) from another, relatively small set of features (land area). In principle, I should be able to do this in QGIS using Vector > ...
2
votes
2answers
65 views

Draw the outline of a point cloud QGIS

I want to know if there is a plugin in QGIS, which will allow me to draw the outline a point cloud. I know there Points2One the plugin, but it makes an outline with all points, even with the data ...
-1
votes
1answer
24 views

Fix AttributeError in python code

I got some code that I think should work, but I'm getting this error: Traceback (most recent call last): File "", line 1, in File "c:/users/proxtr~1/appdata/local/temp/tmpgtrnqo.py", line ...