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

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26 views

Forcing area calculation into miles in QGIS (without changing the PCS) [duplicate]

I'm working on an assignment that requires me to create an area column in miles without changing the projected coordinate system. ArcGIS has a tool that can do this ('Calculate Geometry')-- does QGIS ...
3
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1answer
589 views

How to change default path for “.qgis2” folder on Windows?

I'm working with windows 8 32 bits OS and qgis 2.8.2. The qgis default installing path for ".qgis2" folder is C:\Users\image95.qgis2. This directory stores several usefull components like qgis ...
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1answer
176 views

How to load an (updating) point layer from Access?

I have a database table linked to the QGIS project which contains X,Y & Z coordinate information, which I can display in the Map View window of the project, after having used the “Points Layer ...
2
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1answer
55 views

Executing a QGIS model per feature of a polygon

I have just got into QGIS models and want to run the attached model per feature in a polygon shape file. I have been trying to do this in two ways and neither of them work. I tried find ...
3
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1answer
181 views

Get vertice information and apply to line segments using ArcGIS for Desktop (or QGIS)?

I've recently started tracking bike treks using Strava and I thought it would be interesting to do some analysis on my treks. I am able to import the GPX file into ArcMap and convert it to a point ...
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1answer
42 views

How to display the join field in a QGIS join?

Upon joining tables in QGIS (2.8.2) I am unable to view the join field in the resulting join. Additionally, the join field is not listed in the target table's Layer Properties, even though the other ...
2
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1answer
16 views

Joined Attributes not recognized in mean coordinates

I am trying to find mean coordinates of a shapefile to which I have joined a csv file for population attributes, but these will not show. I'm working with county data of each US state based on the ...
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1answer
119 views

Select a column like Primary Key in a View from PostGIS using PyQGIS in QGIS

Postgresql doesn't support Primary Key in views. When I load a postGIS view in QGIS "manually", I can choose the column that will be the Primary Key, but I would like to know if I can select a column ...
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36 views

Related Spation and non-spatial in QGIS

I am working with QGIS 2.6.1 by adding data from server using PostGIS. Now, I want to see the attribute information. So, how can relate the spatial with the information?
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131 views

How to relate a Spatial and Non Spatial table in PostGIS to be visualized in QGIS

first of all I'm quiet new in PostGIS. I'm working in pgadminIII with postGIS. I have in one database two tables. See the two tables SQL Pane. CREATE TABLE gw_body_characterisation2 ( ...
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1answer
39 views

Create statistics by features in QGIS [duplicate]

I've a polygon layer for parcels in a landscape protection area and a point layer, contains zoological data (e.g species, entities, etc.). How can I make a statics for each polygon, contains the list ...
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134 views

Is there limit on size of GeoJSON files that can be handled by QGIS? [closed]

I'm trying to load a GeoJSON file with about 5K features in QGIS, and it fails, saying Invalid Data Source without further details. If I remove features down to 1K, it works. Is there a limit on the ...
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0answers
84 views

Execute GRASS command within QGIS python console

We try to calculate catchments with the r.water.outlet function from python console. To do so we use the following code: import processing rlayer = QgsRasterLayer("/my/path/DrainageDirection.tif", ...
2
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3answers
346 views

QGIS joins 2 FIELDS

I have an excel with 4 columns (Region; District; village; number of cases) Have a shapefile with dots for villages with many columns including (Region ; District ;Village) I want to plot the cases ...
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0answers
33 views

Making virtual raster with average values [duplicate]

I'm working with many raster files. Is there a way to make virtual raster with average values in each pixel. (QGIS) It's for an NDVI index of summer months over 5 years.
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1answer
64 views

Merge lines while adding attributes spatially

What I have: A shapefile with multiple lines. Example: line 1: A -> B -> C with attributeX=5 line 2: A -> B -> D with attributeX=7 What I want Lines between each nodes with added attributes. ...
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3answers
861 views

Poor performance with storing large rasters in PostGIS and visualising in QGIS

my question concerns the use and performance of several software tools in conjunction, namely PostgreSQL, PostGIS, QGIS, and GDAL. I'm a long-time ArcGIS, Python, and R user who is interested in ...
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0answers
160 views

How to create ROI in Semi-Automatic Classification plugin QGIS

while trying to classify landsat images, I get the following problem: I click on the pixel I want to define a ROI, but the ROI polygon that the plugin creates appears in a different part of the image ...
2
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2answers
115 views

Why does QGIS Vector OpenStreetMap import lose features?

I'm attempting to use OSM data in QGIS 2.8.2. I've imported my data into SpatiaLite layers using the following steps: Vector -> OpenStreetMap -> Download Data... Vector -> OpenStreetMap -> Import ...
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0answers
106 views

Oracle add layer and Oracle Connection icons are missing

I have recently installed QGIS 2.8 and Oracle 11.2 Client on Linux Red Hat 7. Everything was fine, I am able to access Oracle database, as well as running QGIS. Unlike QGIS 2.8 from WIndows, Linux ...
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0answers
17 views

Any experience or tips for using qgis with postgis layers? [duplicate]

we want to replace our shapefiles with postgis layers for editing in QGIS. We plan to edit 1 Layer with 5 people at the same time is this possible? Is this a good idea or is there a better practice ...
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36 views

QGIS Exporting WTF file with specific coordinate units

Frustrated newbie here :( -so thanks in advance :) Making a Geo-tiff file to be used by another program (SMT) as "culture" image. That program requires an associated wtf file with the standard format ...
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0answers
68 views

compare column to atributes in a loop in pyqgis processing

I am creating a script in processing qgis. I am running the interpolation algorithm.I have two tables table A and table B. Table A contains attributes like A_test,B_test up to Z_test. Table B contains ...
3
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1answer
111 views

Table output from QGIS graphical modeler

I have developed my own model, which processes input vector layer. The final output is vector layer that contains many attribute fields, and of course, also the geometry, but I need a simpler output - ...
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1answer
106 views

Dissolve Polygons by attribute leaves empty spaces

I am trying to dissolve polygons based on the same attribute using QGIS 2.8.2 (Wien). I use Vector, Geo Processing Tools, Dissolve and then I select the attribute. The data is Postal Sector in Uk and ...
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0answers
21 views

combining spatial and numerical queries in an expression

I would like to build an expression to return the largest value of a field within a source layer where it is contained within a polygon of the open layer. I want this expression to write the result to ...
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1answer
60 views

Generate maps from different columns of shapefile with QGIS

I have a shapefile with N columns describing different attributes of some features. I would like to generate a grid of maps, where each map is a different column. Visually, I'm thinking of something ...
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0answers
96 views

QGIS 'Save As' Reprojection Produces Different Results from ogr2ogr command line

Another 3857 vs 4326 question. When I reproject from EPSG:3857 to EPSG:4326 (and from .shp to .geojson) via the QGIS 'Save As' dialog, I get results that display in the expected place on Google Maps. ...
3
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1answer
52 views

How do I edit multiple features at one time?

In my case, there are about 30 overlaid features. How do I select all and edit them at one time? I want to reshape the features, mainly using the node tool to reshape a straight line into a (fake) ...
2
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2answers
195 views

How can I eliminate leftover border/boundary in QGIS?

I am trying to generate a shapefile which contains the unincorporated areas of St. Louis County, Missouri. I'm using two shapefiles: St. Louis County from the 2012 census, followed by St. Louis ...
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0answers
78 views

How to get QGIS to display grayscale of an SRTM geotiff?

I cannot get QGIS to recognise my SRTM geotiff as having any grayscale elevation data. In the screenshots below, opening the geotiff file in MicroDEM by default hillshades and pseudocolors the ...
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1answer
145 views

How to conduct an inner join with QGIS?

My QGIS (2.8.2) joins always result in an outer join. How do I create an inner join with QGIS?
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1answer
43 views

Importing Edge List into QGIS?

I have a CSV edge list such as follows: Lat1,Lon1,Lat2,Lon2 93.41823,-104.324324,93.41828,-104.324320 93.40110,-104.310552,93.40108,-104.310557 ... Is there a way to import such a CSV file into ...
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0answers
62 views

Convert manual colored maps to vector

Is there a way to colorimetrically and automatically vectorize georeferenced rasters that came from manually colored, scanned maps? Currently we Print the topography maps 20k scale --> hand-coloring ...
2
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0answers
128 views

Spatial join with multiple intersecting features

I have a polygon dataset representing pavement areas broken up by year of construction and a roads centerline dataset that contains values for remaining service life (RSL). I want to spatially join ...
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0answers
24 views

How to remove lines made with a PostGIS query automatically if origin is not in the map window?

I have a PostGIS point layer with labels. I moved these points because they were too close. To connect label and point, I created a line vector layer which was made with a query in the DB-Manager ...
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0answers
92 views

Problems with rasterization through QGIS Modeler

My goal is to rasterize a vector polygon-based shapefile. Whenever I run in the modeler or even from the Processing Toolbox the Rasterize tool of GDAL, I receive a raster layer that's not good for ...
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0answers
98 views

Hex grid from layer bounds issue

I'm trying to use the 'Hex grid from layer bounds" script to reproduce the simple "Mapping density with hexagonal grids" from the Learning GIS book. When I run the script "as is" I get the error: ...
2
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1answer
98 views

How can I apply a color ramp to a shape file layer in QGIS 2.8?

How can I apply a color ramp to a shape file layer to show something simple like population variance? If this was ArcGIS, I would do it by using the Quantities tab in Symbology but I have been unable ...
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0answers
23 views

Finding how many points are in polygon of layer in specific time using QGIS?

I have the layer that I created with the number of earthquakes in each region in the last 400 years. I want to know the number of earthquakes that occurred in one specific region prior to 1900. How ...
1
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1answer
60 views

Field calculater in Python console from QGIS

I have some doubts in syntax of processing.runalg(qgis:fieldcalculator) in python console of QGIS. I want to create a new field in a shapefile and calculate this formula: [D_PATRICIA]*1000. ...
0
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1answer
167 views

mosaic raster image non georeferenced

I have several jpeg2000 tiles non georeferenced and covering a certain area. I know in qgis you can mosaic image using the merge tool but I have done it only using georeferenced images, which is quite ...
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3answers
673 views

Subtracting polygon from another in same layer using QGIS?

I need to subtract a polygon from another bigger one, in the same layer. How can I do this?
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0answers
31 views

Translate old QGIS (2.2) Sextante model to newer version

Hey there (I guess Victor :-)) I really like the processing toolbox and have realized several models. I also developed some bigger models in QGIS 2.2 / with the former processing toolbox. Since the ...
2
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2answers
215 views

Projecting shapefile with unknown CRS to WGS84 using QGIS?

I've tried setting QGIS to on the fly, changing the layer settings, nothing. I'm at a lost cause. Although I am not a GIS professional. ...
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2answers
146 views

Getting attribute table from WFS data source

I am attempting to get some WFS 2.0 INSPIRE data from the Finnish meteorological institute into a table format of some kind. Is there any software which can easily grab the attribute data for the WFS ...
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0answers
40 views

Creating ROIS in Semi Automatic Classification pluggin Qgis

I am trying to classify a Landsat 8 image using the semi-automatic classification plugin in QGIS 2.6. When trying to define ROIS, I select a pixel of of interest, but the polygon is created ...
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1answer
147 views

Labeling only line vertices in QGIS?

I want to only put labels on the vertices of the polylines. I can use the data defined features to place a label at specific points, but not at multiple specific points. Is it possible to label only ...
0
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1answer
34 views

WMS Server scale problem?

I'm new to the environment QGIS, and my question and problem is when changing a layer coming from http://ide.cime.es/menorca/wms/base_referencia/ I want to load the 1-> 86 layer and at first ...
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1answer
50 views

Render or display only the boundary of a vector layer containing thousands of polygons

This might be a very basic question but my lack of experience makes it really hard to answer. To have a cleaner map to print I want to display only the boundary of a layer composed of more than ...