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

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30 views

In QGIS, how do I limit decimal places in data I imported as .CSV and joined to a shapefile? [duplicate]

I am importing a csv into QGIS 2.4 with a csvt file that specifies for percent columns Real(2.1) to limit it to 1 decimal place. It imports fine. When I join it to a shapefile, it looks fine. But when ...
4
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1answer
109 views

How to create non-overlapping intervals in the legend?

So I am trying to create a legend where the entries are, for example, like this: 1.1 - 2.0 2.1 - 3.0 3.1 - 4.0 as opposed to like this: 1.1 - 2.1 2.1 - 3.1 3.1 - 4.1 I essentially don't want ...
3
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0answers
29 views

Creating a distance overlay that is computed by the distance of points/lines and recalculated on zooming

I created a fictional map and visualized it with d3. Now I would like to show a scale/rule so that the user can see which distance (kilometers,meters) he is currently using. I was thinking about ...
1
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0answers
150 views

Embedding python to select feature in QGIS action

I am working from QGIS actions with python and want go to select the current feature that I've identified using the identify tool. (Key point is that there is a difference between identify and select)...
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3answers
102 views

clipping an area out of multiple satellite images in QGIS

How can I clip the exact same area out of multiple satellite images ( multiple bands)? I am working on a remote sensing project and only need a certain island but the images show much more.
2
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2answers
720 views

focal mechanism(beach balls) for many Earthquakes

Is there a good way to automatically generate focal mechanism (beach balls) for a shapefile with about 30.000 earthquakes and store them ideally in the attribute table. It would be the best if I ...
4
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1answer
671 views

Edit existing polygons to include several new nodes

I want to define catchments which are quite large from vector contour data. I normally start zoomed out to define the catchment generally as it is easier to see. I then zoom in and refine the ...
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2answers
144 views

Shapefile created in QGIS will not display properly in ArcGIS

I was asked to created a point shapefile of a cemetery. The points display correctly in QGIS but not in ArcGIS. I think the issue is with the coordinate system I created it in (WGS 84 / UTM zone 17N). ...
1
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1answer
103 views

How to combine depth and topography .asc file?

I have a .asc file produced from a hydraulic model. The .asc file contains depth data of flood inundation. I want to superpose the depth asc file with my topography .asc file so I can identify where ...
1
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1answer
56 views

Is there any statistical measure/tool that compares two different sets of location configurations in R or ArcGIS/QGIS?

Here is what I'd intend to do; I have a given set of facility locations as shown below; And based on a predefined one optimization criterion, I obtained the following configuration (and there are ...
1
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1answer
425 views

Adding field values to a QComboBox in PyQGIS

I have a layer say 'Cities'. There is a column called 'NAME_1' in the layer. My GUI has a QComboBox in which i want the values of column 'NAME_1' alone to be displayed in the drop down of the combo ...
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1answer
90 views

Buffering in km in NAD83 QGIS

I need to create a 32.1869 km (20 miles) buffer around my attributes, but the problem is the CRS needs to stay in NAD83. Is there a work around so I will be able to create buffers in km but still have ...
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1answer
120 views

Draw lake isobaths having depth points and coast line

For some lakes, I have a line shapefile representing the coast line and some points with many information, among which depth (in meters). Is there a way to draw an isobath linking every point with the ...
2
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1answer
86 views

Loading multiple SpatiaLite layers into a single database

I have many SpatiaLite layers, each in a separate database. I want to load all these SpatiaLite layers into a single database. How can this be done?
2
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0answers
165 views

QGIS buffer polygon with different widths on each side

I create maps for wildfire risk assessments and am constantly asked to plot "defendable space" buffer zones around building envelopes that are different distances on different sides of the buildings. (...
2
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3answers
131 views

In QGIS how do I edit/save data which has no geometries?

In QGIS I can import data tables (CSV in particular) which have no inherent geometry (and no lat/lon columns) into QGIS. There doesn't seem to be any obvious way to manipulate that data (edit/save). ...
0
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0answers
33 views

Spatially joining 2 point layers i.e. pole and customer points using spatial join of PostGIS/PostgreSQL Without intersection and buffer technic

Intersecting customer points with pole feature with 20m buffer SELECT distinct h.gid, d.polecode as gid FROM customer as h LEFT JOIN pole_20 as d on ST_Intersects(d.the_geom, h.the_geom); ...
3
votes
1answer
185 views

Show “Raise Notice” and “Raise Warning” in QGIS

Is there a way to catch "Raise Warning" and "Raise Notice" (while editing PostGIS-Layers) from a PostgreSQL/PostGIS-Trigger-Function within QGIS? One example: I have a trigger that reacts to insert or ...
2
votes
3answers
109 views

Making empty parts of aerial imagery transparent

I have a raster file (ECW format) that covers a very large area, however the contents comprise a thin strip of aerial imagery (100m strip centered over the rail line). The bounding box for the image ...
1
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1answer
169 views

How do I properly import python sklearn to QGIS PyQt plugin?

A bit of background: I'm somewhat new to python and QGIS plugin development. I've created a plugin structure for QGIS using the Plugin Builder on QGIS and I've added some controls to the gui and ...
2
votes
2answers
299 views

How do you change the scale bar units to feet?

I'm trying to change the default QGIS scale bar from meters to feet. From the API documentation it looks like I should be able to use the QgsComposerScaleBar.applyDefaultSize() function. I thought ...
2
votes
2answers
209 views

How do I count the matching 'many' entries in a one-to-many relationship?

I have a simple SHP line file - where each line has a unique reference. I have a related text csv file using the same reference, in a one-to-many situation. I need a map with the lines (in the 'one' ...
2
votes
1answer
566 views

How to find chainage of points using LRS

I have a Shapefile of road that I have converted from a KML file (created on Google Earth) and a txt file containing lat long (from GPS) of points with some attributes. The points are not exactly on ...
2
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2answers
59 views

How to label values every 5th number

I have a string of values(over 10,000) I want to label them but I dont want to label every single one. I need to label every fifth number.
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1answer
280 views

saga_gui.exe identified as malware by antivirus when downloaded from OSGeo4W [closed]

I downloaded QGIS 2.6.1-2 (Brighton) yesterday from OSGeo4W-setup-x86.exe using the advanced installation option on a machine running on windows 7 professional. The download worked Ok except for saga ...
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1answer
283 views

Remove white background in Raster in QGIS

I'm sure this is a very simple task, I have a black and white basemap and i would like to remove the white from it in the latest version QGIS. There are setting in layer properties and bands etc, ...
1
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0answers
55 views

Detecting geometry change between two line layers in QGIS

Looking to find a method of simply detecting if the geometry between two layers (line) has been altered. I have two layers of the exact same features but I suspect there is a difference in some of ...
5
votes
1answer
763 views

Calculate population within radius

I have population data matched with polygons and a set of points that I have drawn buffers around. Assuming that the population within each geographical area, i.e. the polygons, is evenly distributed, ...
2
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0answers
61 views

QGIS one-to-many labels

The one-to-many relations in QGIS is OK with forms, works great. But how to labels or chart data with this one-to-many relations? Martin
2
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1answer
292 views

How to enable the snapping options for vector layer using the python programming?

I want to enable the snapping options for the the existing layers using python programming. How can I do this?
0
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1answer
660 views

How to position the Qwidget form/QDialogBox in the left corner using python programming

1) I am creating a Qwidget Form or QDialogBox using QT Designer. I am using the following code to move the form: sDialog.move(50,450) But i want to fit the dialogBox to fit in the left corner.How ...
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1answer
259 views

Topographic correction (for landuse analysis) with ArcMap 10 or QGIS

I've been searching a tutorial to do topographic correction using ArcMap 10.2 or QGIS for days, unfortunately I can't find a good one that can explain the work (like which toolbox should I use). so ...
2
votes
1answer
163 views

How to measure an irregular road line in QGIS?

I'm trying to measure the distance between some coordinate points along a road line from an OpenStreetMap source map, I am using QGIS 2.4.0. My problem is to find a way to measure these distances ...
0
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1answer
48 views

How to join two plugins in QGIS?

I have created two different plugins in QGIS using python. I would like to combine both in one plugin. How can I do that?
4
votes
2answers
654 views

Adding a vector layer at QGIS start

I have added a shape file in QGIS using Python plugin. I want to add this shape file when QGIS is loading so i have to add code in the initgui() method. I have used following code in the initgui() ...
2
votes
1answer
295 views

map flood inundation risk QGIS

I am using RADAR data to create a map of biomass estimates. I want to mask out all land susceptible to flooding because water-logged soils affect the backscatter ...and will have an impact on ...
3
votes
1answer
847 views

How can I iterate over several layers and run a process using PyQGIS?

I am trying to find road intersections within each of my memory Polyline layers (which are named road_layer_i for i in (0-99)) so this is what I tried: import processing self=qgis.utils layers = ...
1
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1answer
177 views

QGIS Composer Big Red X

I am working with QGIS version 2.01. I created a print composer to export the map with legend, scale bar and title to an image or pdf. When I opened my QGIS project again and went to my print ...
4
votes
1answer
444 views

MapInfo “Boundary Select”, “Sum Attributes”, and “Update Column by Spatial Query” in QGIS? [closed]

I´m a MapInfo user, I´ve gone over to QGIS and it´s got a lot going for it, except for some "missing" simple features from MapInfo I just can´t do without.... MapInfo Boundary Select - spatial query ...
1
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1answer
191 views

Updating QGIS version through OSGEO4W - Unable to get setup.ini

I want to update the QGIS versions that I am using through OSGEO4W. I am currently running QGIS 2.0.1-Dufour (and also have an QGIS 191a229 version) on Windows 7. However, when I go through the ...
3
votes
1answer
463 views

WindowsError: [Error 32] The process cannot access the file because it is being used by another process

I am reading images (through Python) and do something. These images are placed in a temporary file, through: tf = tempfile.mkdtemp(filename) I use gdal to read the images (short part of code): ... ...
3
votes
1answer
97 views

I hid the QGIS Menu bar, how can I bring it back? [duplicate]

I was trying to save customization templates in QGIS 2.4 and have managed to hide the MENU bar. Now I cannot access Settings->Customization to switch it on again. I even un-installed and deleted ...
1
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1answer
139 views

Create polygons from point dataset, where each polygon contains 3 points from the dataset

I'm using qgis Brighton I have a dataset of 1500 points. I want to create polygons, where each polygon contains n=3 points from the dataset. The aim of this is to have clusters of 3 points, which ...
1
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1answer
171 views

How to sum 10 raster bands instead of 9 from code?

I want to sum 10 raster bands but the problem is that the following code will only work for summing 9 bands, which means the output image consists of 9 bands. from qgis.core import * from qgis.gui ...
1
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2answers
168 views

The use of QGIS with a Magic Mouse

I have been using QGIS with an Apple Magic Mouse. Despite disabling all the point and click features and gestures in the systems preferences, the maps constantly zoom in and out extremely and ...
2
votes
1answer
126 views

How to re-project shapefile to be compatible with Openlayers satellite imagery

The goal: Visualize a map using google's satellite (and projection) using my collected points. Right now I have a shapefile of my collected points from surveying. I created it by adding my csv file. ...
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1answer
58 views

How to add neighborhood names from shp to csv data points QGIS

I'd like to add the neighborhoods listed in a shp file to the data points in a csv Link to shp Link to csv Here are the data points overlaid on the shapefile map of the neighborhoods. I'd like ...
0
votes
1answer
106 views

Converting osm_id to OSGB coordinates

I've downloaded from http://extract.bbbike.org/ a map of the waterways and waterbodies within Greater London, Uk. I've loaded the shapefile into QGIS and opened its attribute table. I see that the ...
2
votes
1answer
179 views

SLD based on two attribute values

The map below is produced in ArcGIS software using the multiple attribute visualization tool (a map based on two attributes the color represents different zones based on the zone attribute value and ...
1
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1answer
42 views

QGIS 2.6.1: “no enhancement” option not working on DEMs

When I import DEM raster layers and try to change the contrast to "no enhancement" I get a blank white image in the map window. Changing "black to white" to "white to black", the map remains a blank ...