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

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2
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1answer
121 views

Displaying black background pixels in RGB raster as transparent (QGIS)

I have the following RGB raster and would like to remove the black background (where R=0, G=0, B=0). I'm using QGIS. The problem is that the raster itself also contains black pixels. Using the option ...
0
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0answers
52 views

Generating outlines of islands using QGIS?

I have a (raster) satellite image showing islands. I wish to extract the boundary (shoreline). I tried a simple classification with just two groups (land and water). Unfortunately too many ...
1
vote
0answers
96 views

Using MySQL vector with QGIS?

I have a problem with mysql vector; when I connect to the MySQL table (containing a geometry column), the attribute table is loaded correctly, the map is centered properly but the geometries are not ...
1
vote
1answer
43 views

Displaying current position using QGIS?

How can I display my current position in the QGIS canvas, similar to the "blue point" in google mapsa? I need this to navigate to defined points and I do not want to change the program all the time.
1
vote
0answers
43 views

Find points within X distance with a specific variable

I am trying to use QGIS to find points within 5 meters of each other that all have a value of <50% for a given parameter that has been loaded through a CSV file. I looked in to doing it with a ...
1
vote
1answer
115 views

Merging vector with many polygons to single vector polygon in QGIS?

I am trying to add the boundaries of one shapefile (A) that are contained within a single polygon to the shapefile (B) of that single polygon. Both are at the same projection. I have tried clipping, ...
0
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0answers
29 views

import qgis works in Qgis desktop but does not work in Python [duplicate]

if i write in python 3.5 or 2.7 import qgis ImportError: No module named 'qgis' if i write the same in Qgis desktop scripting - i get no error. Did search the forum didnt find any answers, btw: ...
1
vote
1answer
122 views

QGIS Two people working on one shapefile at once?

Is it possible for two people to work on the same shapefile at the same time? Atm we split the data into two shapes and merge them after editing (version 2.12), but we are looking for a more ...
4
votes
0answers
250 views

“Error” on Advanced Digitizing Window in QGIS

I have the word "Error" that has appeared on my Advanced Digitizing Panel since upgrading to QGIS 2.12.0 Lyon. It doesn't appear to actually affect anything negatively... has anyone else seen this or ...
1
vote
1answer
96 views

Error in converting SpatialPolygonsDataFrame to Data Frame, R Script in QGIS

I am trying to convert a SpatialPolygonsDataFrame layer to a DataFrame to create plots using ggplot2 in an R Script within QGIS. I've used spatial join to append averages of BioClim mean temperature ...
1
vote
1answer
219 views

Adding Esri imagery to QGIS using “services.argisonline.com”

I'm trying to add this particular imagery in QGIS: http://services.arcgisonline.com/arcgis/rest/services/World_Imagery/MapServer/3 But when i write the phyton srcipt i get the message that the URL ...
1
vote
1answer
64 views

Spline Tool does not work

In QGIS 2.12 the curves tool is integrated by default, I know. I would like to test the Spline Plugin whether it works better for my purpose or not (purpose is just to digitize streets mit nice curves,...
1
vote
2answers
250 views

Converting MapInfo workspace/QGIS project to ArcGIS for Desktop?

I need to deliver maps in ArcGIS format to a client, but I only work in MapInfo and QGIS. Is there any way to convert a MapInfo workspace or a QGIS project to ArcGIS for Desktop, keeping styles and ...
1
vote
1answer
110 views

Slope analysis of DEM in QGIS?

I have very strange problem with the raster analysis. I have a DEM as a Geo tiff and I do a slope analysis in QGIS. I've done this many times and everything was ok but this time I received reversed ...
4
votes
1answer
124 views

Use “facet_wrap” in ggplot2 with QGIS?

I'm using QGIS 2.6.1 and R version 3.2.2. I'm struggling to get the syntax on a R Script for creating plots via QGIS processing to work. My understanding is that R syntax in QGIS Processing is ...
0
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0answers
102 views

How to measure nearest neighbor in miles or kilometers between two point layers using QGIS?

I have tried to look for an answer to this question, but cannot find an adequate solution. I have two point layers. One is of locations by lat/longs of homes in Louisiana. The other is a layer of ...
1
vote
1answer
70 views

increase resolution of generated hillshade on QGIS

I want to export a hillshade (geotiff) created from a DEM as an image for printing. But the resolution of the hillshade is way too low (900 colums, 1450 lines). Any way to upscale it? (I tried ...
1
vote
1answer
69 views

Bathymetric-topographic DEM color relief?

I am using QGIS 2.12 on a Macbook Pro running OS X 10.10.5. I have an interesting DEM for the California coast (which I downloaded from Santa Barbara, CA 1/3 arc-second MHW DEM. I've been playing ...
0
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0answers
21 views

ETRS89-LCC true scale

With QGis 2.12.0 I made a map with the "EPSG 3034 ETRS89-LCC" I then modified the parallels of latitude with custom ones by the rule of 2:6, so from: +proj=lcc +lat_1=35 +lat_2=65 +lat_0=52 +lon_0=10 ...
1
vote
1answer
397 views

How do I install qgis lyon with grass access

I am working wit a win10 64 bits 16mb of ram. I want to install Lyon on my computer and not get rid of 2.83. My 2.83 is a stand allone install. I thought I could install Lyon usion OSGEO 4w installer. ...
0
votes
1answer
41 views

Converting census data to block groups with regard to their area

I have population data for census blocks and want to convert them to block groups. I know that block groups has an extra digits, but how it will be possible to break down census data between blocks ...
1
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0answers
37 views

Generating lines from one polygon to a group of polygons (one to many network) using QGIS?

I have a polygon layer where every polygon has a unique ID, and another polygon layer where those unique IDs can be found in a column in a one-to-many relation. I would like to have QGIS draw lines ...
3
votes
3answers
217 views

Comparing Column Contents in QGIS

I am trying to compare the contents of two columns named C1 and C2, each of them having some 250 values. I want to create another field, named C3, with TRUE if a value from C1 is found anywhere in C2, ...
1
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0answers
37 views

Creating look up tables in QGIS that last more than one session?

It seems that when I create a Look up Table or Value Map for a shapefile or a PostgreSQL table in QGIS it saves it for one session, then when I open it again it had disappears. Can someone ...
1
vote
1answer
26 views

Locking annotations to base map in Pisa Composer?

In Pisa Composer: I am creating a complex geologic map. I created geologic base map and then added annotations (notes, arrows) in Composer. I need to lock the annotations to the base map in ...
3
votes
1answer
47 views

Help with Rastercalculator - Filter areas with a certain height difference

I'm struggeling a little bit with the rastercalculator tool of QGIS. At the moment I am working with a DSM and a DTM. My aim is to filter all wind turbines out of the DSM and replace it with the ...
1
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0answers
43 views

VRTs (vector union layers) not working in QGIS

I have created a set of VRT's for base mapping vector tile layers following this tutorial This works well for displaying the layers but If I want to export or copy out a subset of the features the ...
1
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0answers
31 views

Processing.runalg is working in qgis python console but not producing output when executed in cmd

This is my code : import sys from qgis.core import * # Initialize QGIS Application QgsApplication.setPrefixPath("C:\\ProgramFiles\\QGISBrighton\\OSGeo4W64\\apps\\qgis", True) app = QgsApplication([]...
1
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1answer
101 views

How to save aliases and metadata in shapfile in Qgis

Is there a way to save the aliases in a Qgis shapefile? When I save the shapefile in a different name or open it in a different Qgis project the entered aliases are disappeard. Same for metadata. Is ...
6
votes
3answers
551 views

Extracting vector/point data from single-layer, non-georeferenced vector PDF file

I am trying to extract point data from a non-geo-referenced vector PDF file, to import into QGIS/ArcGIS. You can download a copy of the PDF file here, if interested, but I've tried to include ...
3
votes
2answers
93 views

Joining points to nearest line using pyQGIS?

I followed this suggestion to join points to nearest lines in QGIS. While most points get attached there are instances of points, often in close proximity to a line, that do not get connected (see ...
1
vote
1answer
78 views

CartoDB QGIS plugin: export/import projection shift?

Original datasource is a postgis db table "Verkavelingen" using epsg 31370 as is my project file EPSG:31370 OTF I have used CartoDB QGIS plugin to export that table to a dataset on CartoDB "...
4
votes
0answers
74 views

SAGA Tool in QGIS Error: Load table: Proj.4-WKT Dictionary… failed

I have some problems with running SAGA tools in QGIS. I've downloaded and installed the software via the OSGeo4W Installer. It downloaded QGIS 2.12 and Saga 2.1.2. I wanted to use the Tool "Shapes To ...
2
votes
1answer
39 views

applying a gradient to terrain curves in QGIS: problem

I'm trying to apply a gradient to terrain curves generated from a geotiff. I then choose a graduated style with a gradient color palette. everything seemed fine until I noticed that from a certain ...
2
votes
1answer
65 views

How to write QGIS script to load Output file to Map Project with Desired Name?

Good news: the following line of code does produce the output as a shapefile with the name I want ("MyFile") and where I want it ("path"), path = "/Users/User1/Desktop/" processing.runandload('qgis:...
2
votes
0answers
53 views

Split Polyline QGIS - Too Many Resultant Features

I'm trying to split a single polyline into 2 polylines (I have lines that loop back on themselves, and I need to split each one into two lines: one for going, and one for coming back). When I use ...
0
votes
1answer
39 views

Reprojecting Tifs [duplicate]

When I import some geotifs into QGIS, they use a reference of 0, 360. My basemaps are all -180, 180. Both the basemaps and geotifs use the same CRS, WGS84. So the geotifs display starting at 0 on the ...
1
vote
0answers
170 views

python script in QGis - help using gdal.Polygonize

I want to create a very simple script in python that polygonizes a raster. Based on python cookbook + forums search I wrote the following code #import des modules from osgeo import gdal, ogr from ...
0
votes
1answer
52 views

OS Web GIS for a travel blog [duplicate]

I have had this idea for years now and would finally like to fulfil it! I was always bothered by text-heavy travel blogs. Therefore, I aim to have a Web-GIS based travel blog in two years time. The ...
2
votes
2answers
66 views

QGIS: Saving a Vector Layer renames the column field title as “cen2010_1”, etc

I'm trying to create a custom subset block map of the 2010 Census shapefile for Massachusetts. I've joined population data from other DBF files and am trying to save the shapefile vector layer as a ...
1
vote
1answer
49 views

QGIS and 'Layer to labelled layer' plug-in

I'm giving a try to this plug-in and I noticed this: When you use this plug-in on a layer, it adds a lot of field in the layer table. The field LblColor has a 7 character field, but it needs a 'r,g,b' ...
1
vote
1answer
98 views

Spatial join multiple attributes from smaller polygons to the bigger one

I'm trying to join (to the rectangle) values from multiple polygons intersecting for this rectangle. I've tried to use some Reference functions in Field Calculator like geomintersects() but it joins ...
1
vote
2answers
62 views

How to set independent path in QgsOverlayAnalyzer >> intersection statement using Python?

How to set independent path in QgsOverlayAnalyzer >> intersection statement using Python? QgsOverlayAnalyzer.intersection(QgsVectorLayer, QgsVectorLayer, QString, bool onlySelectedFeatures=False, ...
1
vote
2answers
142 views

Mapinfo Vertical Mapper interpolation VS QGIS

I am currently trying to fade out the use of MapInfo and only use QGIS (or Global Mapper) however I find that I am still needing to use Vertical Mapper for interpolations. We are using MapInfo V12 and ...
1
vote
0answers
122 views

Raster layer not visible after changing color rendering in Qgis

I created a new raster and it appears in the layer list, its visible on the screen and the values seems to be correct. When I change the "band rendering" from "Singleband gray" to Singleband ...
2
votes
0answers
23 views

QGIS 2.12 Symbology does not work correctly [duplicate]

I use QGIS for a long times on mac and windows and i have a problem with the 2.12 version on my OSX 10.8.5 when I want to edit style of my vector layer. When i click on properties of a vector layer ...
6
votes
1answer
218 views

Centrally stored QGIS print templates

In my organisation we would like to have a set of organisation configured print templates. It would be convinient to stores these at some central location so we only have one copy of the templates. ...
2
votes
1answer
34 views

Get values from metatada.txt

Is there a built in function in PyQGIS to import the values from a plugin's metadata.txt? I am developing a plugin and want to show the version corresponding to the value from metadata.txt. Is there ...
3
votes
1answer
266 views

QGIS : Creating point feature from Lat, Lon SQL Server 2008R2 data import

I am importing a table having no spatial columns from SQL Server 2008R2 database into QGIS 2.10.1. The table has latitude & longitude values. How can I create point features using the latitude, ...
2
votes
1answer
82 views

How detailed should I make the shapes.txt for a General Transit Feed?

I am working on creating a transit feed with General Transit Feed Specifications in mind. I'm torn into how detailed the routes should be for the shapes.txt. Do I map just when the bus is on the main ...