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

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3
votes
2answers
254 views

Can't export customer's shapefile to latitude and longitude

I'm very new to this application so bear with me. I hope that I am missing something very elementary. I have a shapefile supplied by my customer. I need to get the latitude and longitude for each ...
1
vote
0answers
61 views

Gradient fill based on scores (similar to elevation)

I'm rather new to using GIS (QGIS, specifically). I've mapped out a cohort of around 550 patients across Long Island, New York based on their full address by using MMQGIS plugin. This data is ...
0
votes
1answer
153 views

Creating slippy map from large shapefiles? [duplicate]

I am trying to create a map of the UK based on a number of open data sources (Ordnance Survey Open Data, OSM, some CSV files etc). My end goal is to create a map of the whole of the UK that I can ...
5
votes
2answers
795 views

How to digitize building footprints with orthogonal edges?

Using QGIS, I am trying to digitize an old raster map, and because I ultimately want to load these 2d layers into sketch-up to turn into 3D models, I need everything to be square. Here's a sample of ...
1
vote
0answers
297 views

ECW support for QGIS 2.8 (Wien) and Ubuntu 14.10 (Utopic Unicorn) [duplicate]

Getting QGIS 2.8 (Ubuntu 14.10) ready for ECW files is really a pain. I've no terminal experience and it took me several hours to install the ECW JPEG 2000 SDK 3.3. What I did so far: #download ECW ...
5
votes
2answers
639 views

How to add a legend to a canvas in a standalone PyQGIS application?

I am trying to develop a standalone PyQGIS application. The map display does not pose any problems, but I do not know how to add a legend to the canvas.
3
votes
3answers
1k views

Which UTM zone to use for a large country?

I want to reproject OpenStreetMap roads data from the current projection (WGS 84) to UTM, since I read in another GIS.SE discussion (How to get $length in meters in QGIS?) that WGS 84 cannot be used ...
0
votes
1answer
444 views

Converting .ecw to .jp2

Is there any easy to use software for converting .ecw/.eww files to .jp2/.jpw files without loosing the georeferencing? I don't want to use proprietary file formats with QGIS. EDIT: I've deleted the ...
1
vote
2answers
394 views

How can I get features that satisfy a QgsExpression using PyQGIS?

I have two fields say "State" and "name" which would be get from the two comboboxes. After which, based on the current text in the combo box, I want to make QgsExpression and feature that satisfies ...
0
votes
1answer
114 views

How to access shapefile m-values with pyqgis?

Does anyone know how to access (read/write) m-values of a line-shapefile using pyqgis? I know how to do it with arcpy cursors ...
0
votes
1answer
47 views

How to convert a specific multipolygon to minimum polygons

I've got this kml file with one multipolygon inside. A link for the file are here multipolygon.zip My goal is to get a multipolygon with the minimum count of polygons with only outer border and ...
1
vote
1answer
632 views

Problems installing QGIS 2.8 Wien on Windows 7

Having trouble upgrading from QGIS 1.8, which ran just fine, to QGIS 2.8. I'm running 64-bit Windows 7. After uninstalling QGIS 1.8, I've been trying for several days to install the 32-bit version of ...
1
vote
2answers
178 views

Having trouble matching up U.S. Census shapefiles in QGIS

I'm trying to use the U.S. Census shapefiles to figure out what census blocks make up which state legislative districts. I decided to test the method on a state where I already had this data to see if ...
1
vote
1answer
348 views

QGIS custom Form - How to bind a value from a QComboBox?

I am trying to build a custom form for field data collection (bird species) with some python logic. The python code inserts values into a QComboBox: At the beginning of the list it adds the twenty ...
2
votes
1answer
347 views

How to implement Add feature action from PyQGIS

I'm trying to implement / reuse Add Feature functionality in my python plugin. there a class/function that handles geometry creation on canvas based on layer geometry definition? I'm checking API but ...
2
votes
2answers
88 views

Placement for Label

Is there I can define expression for the placement of label in vector layer like when the scale is less than x label placement should be curved else it should be horizontal. I am using Pal setting. I ...
2
votes
1answer
272 views

How is QGIS opening a shapefile with no *.prj file?

I was wondering how QGIS could open a shapefile with no *.prj file (for instance, let's say we have a shapefile with just *.shp, *.dbf and *.shx files). If the On the fly reprojection option is ...
1
vote
1answer
55 views

Converting integer value to unicode for labeling in QGIS

It is possible to stylize a layer with integer numbers stored in a shapefile and then choose a symbol out of a font. I would like to use the label engine instead, because i'm more flexible, for ...
1
vote
1answer
97 views

Old question without answer: R.Neighbors with large neighborhoods?

I'm working on the same theme as User 32882, and I'm new here. I have the same problem, and update his question with more details. Old question: "I'm running into problems running the r.neighbors ...
1
vote
2answers
224 views

multi-sheet printing of large-scale maps

Mapping a specific region at a larger scale, this region does not fit onto a single sheet of paper. For example mapping Austria at 1: 1 mio needs three sheets of din a4 paper. Question: Can I do ...
0
votes
1answer
75 views

cross referencing files question

This may be an easy question so please forgive me if it is (or if it makes no sense) as this is all very new to me. I have 3 files that I am trying to cross reference. One file has columns category, ...
3
votes
1answer
58 views

How to save .shp with layers 'baked' in with QGIS

I'm having no problem applying labels to the shapefile I'm working on in QGIS, but I can't seem to save the new shapefile with the layers 'baked in' for uploading to Mapbox, and then styling. I've ...
0
votes
2answers
207 views

Geoserver WFS-T not saving edits from QGIS to MS SQL layer

I added a MS SQL layer from my Geoserver to QGIS. It will save changes for attributes in the table and it will save the file if I delete features. However, if I add a feature or change a feature, it ...
0
votes
1answer
220 views

Conditional calculation - QGIS Raster Calculator or GRASS r.mapcalculator

Is it possible in QGIS either directly or via plugins to do a raster calculation including an if statement? e.g., if raster1 > 0.3, then raster 1 * raster 2, else raster1 x raster3...something like ...
2
votes
1answer
83 views

How to add a VFR map coordinate grid in QGIS?

I want to add a coordinate grid like in the link below to my map. A simple grid is no problem, but I would like to know how to add the fragmentation of the lines.
2
votes
1answer
118 views

Disaggregating vector layer splits

I'm fairly new to GIS, but I've got the basics down. I'm utilizing QGIS and Python to calculate election statistics by legislative and congressional districts. I'm trying to aggregate precinct level ...
4
votes
1answer
871 views

Select by location in Python

I have a polygon layer and a point layer (with coordinates for each point). The polygon layer got created using the MMQGIS PlugIn (Hexagonal Polygons). I want to select all the points inside each ...
2
votes
2answers
84 views

Showed object number is not correct

In the attribute table for a layer I have 13 Objects and if I switch on object number button. I have 16 Objects and this is wrong. I couldn´t find a way to correct this? On the left side you see VK ...
0
votes
1answer
109 views

QGIS raster calculator wrong output

I am trying to create a mask from a DEM (SRTM tile) using raster calculator in QGIS. I have performed the same operation in ver 2.6 with no problem but in the current version the output is incorrect. ...
6
votes
2answers
314 views

What is the theory behind graduated symbols in QGIS?

QGIS offers 5 methods of classifying vector map data (quantiles, equal interval, etc). What is the theoretical base of these methods? If there are certain methods suitable for certain types of data or ...
1
vote
2answers
1k views

What causes large shapefile file size and can you effectively reduce it?

I have a shapefile that contains all counties of Poland in one shapefile. The shapefile is provided by central cartography agency. The file with counties they provide is around 30MB. The same ...
2
votes
1answer
2k views

QGIS 2.6 - installing exifread for photo2shape plugin

I've already seen Error loading plugin photo2shape even after installing exifread module and Error installing Photo2Shape QGIS 2.6 for Mac, and other forums, but can´t make it work. First I installed ...
2
votes
0answers
761 views

Merge several images and Export a GeoTiff File

I have approx 500 geo-referenced images that I was hoping to merge into 1 geo-referenced file, and export it as a single geotiff file. To be used in AutoCAD Civil 3D I know I am pushing my luck and ...
3
votes
2answers
784 views

Using folder wildcards to copy files with Python

I would like to copy the data of one specific shapefile from a specific folder ("Grid") to a number of folders containing the name "Country". The country shapefiles would keep their original name. ...
1
vote
0answers
25 views

importing MapInfo georeferenced ratser on qgis 2.2

I do not understand why loading mapInfo shapefiles is possible in Qgis but for the georeferenced image file, is there any possible reason for this? My major concern is that, so far georeferencing on ...
2
votes
0answers
140 views

QGIS, How to label a layer in different font sizes, shrink to fit in polygon or a multiple line label?

I am just trying to figure out how to label a polygon layer to fit its size in QGIS. or if its very long title should break in line and scale, i did some research but couldn't find anything helpful is ...
2
votes
1answer
105 views

How to change GK-coordinates to UTM with the field calculator in QGIS?

i have a qgis project in ETRS89 (UTM) with some vectorshapes. i already transformes them from GK into UTM. but now the attribute table still show me the GK-coordinates. HOW can i change it? with the ...
2
votes
2answers
297 views

How to generate line segments between all points

How do I create a vector layer with a network of line segments drawn between every point in another vector layer? Basically, I am trying to create something similar to a hub/spoke network, except ...
3
votes
1answer
92 views

Concentric Ellipses around polygons as a representation of density

I have someone who has given me a thumbnail of a map with some concentric ellipsoids placed in estimated high density locations for our business. One location has three, and two other location have ...
0
votes
2answers
625 views

Extract Elevation of Points from DEM using Python QGIS or GRASS

I am utterly new to GIS, so please bear with me if I am providing incomplete information here. I have a DEM file (.dt2). What I am looking to do is as follows: take a series of points specified as ...
1
vote
1answer
233 views

Adding points defined by Latitude and Longitude to map using QGIS?

I have an OS map on which I want to display points defined by Latitude and Longitude, but the map coo-ordinates have values I do not recognise or understand. The image shows the map, with my first ...
0
votes
0answers
29 views

query from shapefile to obtain all long, lat from a point table

So I have two files, one is a shapefile with multiple shapes and shape-length, and another file with long, lat coordinate points. I would like to query for each shape in shapefile all the points ...
1
vote
1answer
178 views

Editing attribute table on QGIS 2.2?

I work on QGIS 2.2, and I am unable to edit my attribute table to change the field type from string to double. I have gone through several tutorials. - I can not run the table manager plugin, ...
1
vote
0answers
53 views

QGIS Partitioning Regions

I have to polygon shapefile maps in QGIS that cover the same area. One with ~90 polygons (call them regions) and the other with about ~800 polygons (call them zones). I want to add a data column in ...
4
votes
1answer
262 views

Modifying straight line segments so they follow geodesic / great circle paths using QGIS

I have a kml file showing a dodecahedron stretched across the surfce of a globe, which I downloaded here: http://montalk.net/cgi-bin/coordinates.py I would like to re-project this dodecahedron so I ...
1
vote
1answer
57 views

Is it possible to overlay ungeoreferenced raster images in the QGIS Desktop Browser?

Afternoon ladies and gentleman, I work for a company that produces Mining Investigation reports for property in the South West of England and I have spent the last 12 months digitising abandoned ...
2
votes
1answer
163 views

Not able to load any Raster File using QGIS Python

I am trying to run an elementary piece of Python code, that simply loads a dem file as a raster accessing the QGIS Python API. On the embedded console (within the QGIS application GUI), it runs fine ...
2
votes
1answer
82 views

Rename output shapefiles in PyQGIS

I have a shapefile which resides in a folder, gets processed and the output is saved in another folder. Before the output, I would like to rename the shapefile slightly differently from the original: ...
1
vote
2answers
566 views

QGIS Rule Based Rendering

I am looking for an example of how to use the QgsRuleBasedRendererV2 to filter features of a layer based on an attribute value (0 or 1). Has anyone done this in Python or C++?
1
vote
2answers
226 views

QGis 2.8.1 crash even after reinstall

I've been using QGis for quite a few years. I normally update QGis to the latest version once it is released on qgis.org, without uninstalling previous versions. I've never encountered any problems ...