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

learn more… | top users | synonyms (1)

3
votes
1answer
164 views

How to compute average slope and area-weighted average slope?

I am learning GIS for use in hydrologic analysis. Related to computation of overland flow there are two types of slope that I would like to be able to obtain from GIS. The first is average slope for ...
0
votes
0answers
5 views

how not to enforce lowercase on spatialite

I use a geojson file to publish a webmap. when i need to update the data, i convert it to spatialite and add the data then again convert back to geojson. Recently in qgis 2.8, i found that the column ...
15
votes
1answer
2k views

Can QGIS preserve layers when exporting to PDF?

In ArcMap, when you export data to PDF it preserves the layering within the PDF so that you can turn on/off individual map layers (within the PDF itself). When I export from QGIS to PDF, I don't ...
11
votes
4answers
4k views

Is it possible to export GeoPDF from QGIS?

Is there any plugin for QGIS which would help me in exporting the map document as a GeoPDF ?
1
vote
1answer
3k views

QGIS - Export PDF map with georeferenced data [duplicate]

I am used to working with ArcMap but have been playing around with QGIS. When I export a PDF map with ArcMap, the PDF is spatially referenced. This is a handy tool, I can put the PDF map on my iPhone ...
4
votes
2answers
673 views

How to add Georeferenced PDF as layer to QGIS 2.0?

I have some georeferenced pdf's that I would like to open in QGIS. I have read that GDAL version 1.8 and higher will support pdf, and I have GDAL 1.10 installed with QGIS 2.0 on Windows 7, but when I ...
0
votes
2answers
50 views

Can QGIS export Geospatial PDF for Avenza PDF map app?

Since QGIS uses GDAL, does any map exported as a PDF become a Geospatial PDF? I am hoping to import maps from QGIS into the Avenza PDF Map app on my phone. Previous posts mentioned exporting as ...
0
votes
0answers
8 views

Get table of adjacent polygons

I am using the cb_2013_us_zcta510_500k shapefile to push zipcode polygons. I have the shapefile, and a SQL Server table loaded where the polygon is loaded in the GEOG data type. What I need is to ...
0
votes
1answer
30 views

Georeferencing raster in QGIS

Georeferenced raster in the QGIS not filmed the final display by raster footprints. Everything is in EPSG 32633. Path in GdalToools: Red is original footprint for image. I need rotate image ...
2
votes
1answer
59 views

QGIS equivalent to ArcGIS Aggregate Polygons?

I am looking for a tool in QGIS 2.40 that performs the function ArcGIS refers to as Aggregate Polygons. Basically it takes a group of polygons within a specified distance and creates a concave hull ...
6
votes
3answers
283 views
+50

Where does QGIS write its error log messages?

I want to read and copypaste the error log for the crashes I am experiencing in QGIS 2.0. The error I am getting freezes QGIS so I have to ctrl-alt-del. I can see the last message in the panel, but ...
6
votes
1answer
306 views

Can I create a reusable text annotation style in QGIS?

I want to create a fairly simple map with a few locations emphasized using annotations. I don't like the default annotation formatting: So, I've reformatted the annotation background color, ...
0
votes
0answers
29 views

Problem filling raster “gaps” (No-Data cells) by means of different raster

Let's assume I have two (or more) rasters with different resolutions which describe the same area. I would like to combine them - fill "gaps" - use value from the second raster when value in the first ...
1
vote
0answers
33 views
+50

How to make a local copy of a large WFS dataset?

We are writing a application in which a part of the job is to fetch a relatively large (>10000 features) and often updated dataset from a WFS server, store a local copy, and do geospatial analyses on ...
0
votes
0answers
17 views

Activating GRASS GIS in QGIS

Apparently, my linux ubuntu setup of QGIS doesn't contain grass gis, although when I initially installed it last week I added grass gis to the command line. Anyway, I typed in once again and installed ...
0
votes
0answers
24 views

How to get a “clean” polygon after using dissolve in QGIS?

I'm trying to obtain the boundaries of shapefile, thus to clean the inside as a matter of speaking. While I had expected that dissolve while get me a proper polygon, unfortunately it still has some ...
0
votes
1answer
127 views

Determining unknown Coordinate System using QGIS?

I'm trying to figure out the coordinate system of some data I downloaded from a no-longer-maintained USDA website. The data's still accurate, it's just floating in space. I've tried several ...
0
votes
1answer
35 views

Getting the nearest point and applying attribute filter using Distance Matrix in QGIS

I have two point layers, one with 233 row, other with 1531. For every point in layer 1, I would like to get the closest point from layer 2, (ok simple enough, but here's a trick) that has the value of ...
2
votes
1answer
417 views

query / filter on attribute tables with external tables joined

i tried to do some queries on joiend table fields ... i've got/found some answers concerning version 1.8 - which result in "use select + export to create a combined dataset" so i just did some tests ...
1
vote
1answer
31 views

How to fix “Detected out of bounds geographic extent”

I hope someone can help me to solve this problem. i want to make a map with TileMill v.01, when i try to add layer using shapefile (i use QGIS to edit *.shp file) or postGIS i always get error ...
1
vote
0answers
17 views

Digitising - Separate fill and line opacities (or remove fill)

I have a client who specialises in aerial photograph interpretation and is in the process of moving from AutoCAD to QGIS. They find the auto 'fill' when digitising polygons really disruptive and ...
0
votes
1answer
85 views

Match bicycle routes to street lines

I have a KML layer of bicycle routes and a street line layer. Using either ArcGIS or QGIS, how can I select the streets that correspond to the bicycle routes?
0
votes
1answer
29 views

How to eliminate polygon overlap areas in QGIS?

Is there a way to remove polygon overlaps within the same layer using QGIS, preferably removing the overlap area of the biggest polygon (having the greatest surface)? All of my polygons are in the ...
14
votes
3answers
859 views

Is there an automatic function in QGIS to package all files in a project for transferability?

In my project, I use a lot of geodata from different directories. Now I want to give the QGIS project to a colleague (eg on a CD). Is it possible to copy the shapes from different directories ...
0
votes
0answers
13 views

Legend disappears in QGIS 2.8 composer

I would like to keep my legend on as I export a multipage map set to PDF, but the legend appears to lose any layer items and just keep the title ("Legend"), which is what appears in my PDF document. ...
1
vote
1answer
20 views

How to write a vector layer as tab delimited txt file using PyQGIS?

I'm using the following QGIS 2.8 Python code to save results to a txt file QgsVectorFileWriter.writeAsVectorFormat(inputLayer, "D:/dstest/my_csv", "CP1250", None, "CSV",True) I would like to be ...
1
vote
1answer
34 views

portions of edited shapefile will not draw

I edited a shapfile of approximately 1500+ pipe segments yesterday in QGIS. When opened today (first in ArcMAP by another user) only about 10% of the pipes were drawn. The same happened when the ...
1
vote
1answer
18 views

Is it possible to display irregular values in the scale bar in QGIS 2.8?

Is it possible to display irregular - increasing values in scale bar in print composer? For example: 5, 20, 100, 250.
0
votes
0answers
39 views

How to create a Shapefile of a subset of input features in PyQGIS?

I'm having some trouble applying my Python skills to develop some scripts in PyQGIS. For me it's far simpler to write it in ArcPy, but then again I wouldn't get that much satisfaction after finishing ...
0
votes
0answers
11 views

Is there an easier way to package all data in a map file in QGIS? [duplicate]

Similar to the way an InDesign file has the ability to package all of the linked images and embedded fonts into its own folder—or how ESRI does it, is there a way to gather up all of the data layers ...
0
votes
0answers
16 views

Is the QGIS connection with ArcGIS “mapserver” still working?

I would like to add the Ocean Basemap to QGIS. I also found the other posts and I followed this procedure: http://hub.qgis.org/wiki/quantum-gis/Arcgis_rest Hovewer when I put in the Python console ...
1
vote
1answer
56 views

QGIS GPS Information Menu Automatically Add Points

We are using a Surface Pro 3 with Windows 8.1 64bit, Bluetooth GPS, and QGIS (2.4 standalone download). We have opened a new QGIS project and are able to connect to the GPS unit within the GPS ...
1
vote
1answer
130 views

How do I install mdenoise in GRASS?

How do I install mdenoise in GRASS 6.4.3? I've already successfully installed r.denoise, and have downloaded mdenoise from wget http://www.cs.cf.ac.uk/meshfiltering/index_files/Doc/mdsource.zip. How ...
25
votes
4answers
6k views

How to smooth a DEM?

I have a SRTM DEM and I want to create a shaded relief from it. I created the shaded relief in GRASS and the result is very nice, but a little rough becouse the area is near flat and the DEM is 90m in ...
1
vote
0answers
18 views

Are there limitations for QGIS Composer images larger than 32768 pixels?

We are outputting a map file with composer : size 45,312 pixels width and 4,352 pixels height in TIFF and PNG format. The map is calculated but in the file we have only 32,768 pixels width show, the ...
1
vote
0answers
15 views

Calculating “sun time” on areas with high mountains? Topography available

I'm wondering how to proceed if you want to calculate how a location on land will get direct sunshine at a given time on a given date (compared being in the shadow of the mountains)? The area is very ...
0
votes
0answers
20 views

Radius settings under IDW interpolation Qgis [on hold]

I have a point data set that I want to interpolate in Qgis. I use the Grid (interpolation) under: Raster- analysis- grid(interpolation) - IDW. There is several things to tweak the output with that I ...
0
votes
1answer
19 views

Geocoding - looking to identify county from list of zipcodes

Using QGIS, how do I find county of an associated zipcode? I have zipcode for each point, however, I do not have a street address. I am hoping to aggregate my data to the county level using the ...
0
votes
2answers
38 views

How to close a polyline in QGIS while digitizing?

We need to work on a line layer where some features are closed and some are open. The closed features need to be closed perfectly, so that the first and the last point of the polyline perfectly match. ...
0
votes
0answers
12 views

World DEM vs ASTER Digital Elevation Models accuracy

I use DEM essentially to create surfaces on AutoCAD Civil 3D and then to create terrain profile views. I have been using mainly ASTER imagery from which I extract 2m contour lines in QGis and then ...
1
vote
1answer
19 views

Taking a long time to load tables from oracle to QGIS

My workplace has an oracle database with a very large number of spatial tables. Therefore, it takes a long time to load the oracle connection in QGIS. Does anyone know how this could be speed up?
0
votes
0answers
11 views

pyqgis, features geometry type changes to unknown after copying to anoter layer

Im copying a subset of features from a shapefile based QgsVectorLayer (polyline type shapefile) to a memory based QgsVectorLayer('LineString', layername ,'memory'): ...
0
votes
0answers
15 views

QGIS 2.8.2 Road Graph doesn't accept road network vector

I'm using the Finnish official Department of Transport's "digiroad" road network vector file, which has all kinds of roads, cycle paths etc on it, but I can't use Road Graph on it. If I create a new ...
8
votes
5answers
7k views

How to change the order of features in a shapefile?

I have a shapefile and I want to change the order of the features. Is that possible?
1
vote
0answers
32 views

Merge vector layers problem with german names (ä, ü, ö…)

When I'm trying to merge (saga merge layers tool) some shape files I get an error log 'ascii' codec can't decode byte 0xfc in position 91: ordinal not in range(128) See log for more details ...
0
votes
0answers
18 views

Can I mimic the “open” action with python and manipulate the field content used for the action?

I am using QGIS actions (type: "open") to link ECM searches to objects on the map. The basic syntax is very simple: protocol://searchterm1=[%"field1"%]&searchterm2=[%"field2"%] However, some ...
1
vote
1answer
20 views

Receiving NULL values from Point Sampling Tool in QGIS

I am using QGIS 2.8.2. My project includes a raster layer of flow depth representing the output from a flood simulation (.DAT file). It also includes a vector layer of points representing the ...
0
votes
0answers
17 views

Why does the “local maxima” module in SAGA GIS put so many “maxima” points on lakes and plains?

SAGA GIS puts too many maxima points on plains and lakes. Why does it happen? Is there a way to avoid this? It's not really a big problem (the value is correct) except for the size of the SHP files in ...
0
votes
0answers
19 views

Quick way to select by attribute and zoom to selection in QGIS

I need to visually control hundreds of points in a layer on top of aerial photographs. Using the attribute table, selecting (with column filter expression) and zooming manually is cumbersome - so I ...
0
votes
1answer
29 views

Function to merge geojson and csv data in R

I have been using merge() to merge my geojson file with csv data in R. My codes are as follows: map@data <- merge(map@data, csvdata, by.x="ID", by.y="ID") However, after exporting the geojson ...