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

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2
votes
2answers
40 views

Change line into multiple segments where they overlap with nodes and vertex (qgis)

I have one (very) long line (e.g. line 2) I also have another line (line 3) which nodes are snapped with two vertexes of line 2. I want to break line 2 up in three segments. Is this possible by using ...
2
votes
0answers
22 views

Error while loading shared libraries libqgis_core.2.9.0

I have complied QGIS version 2.8.1 from source, according to the instructions from https://github.com/qgis/QGIS/blob/master/INSTALL Now after successfully running ccmake .., make and make install ...
-3
votes
2answers
53 views

Fractional Area Calculation

I have a file (in both raster and vector) of different districts in a country. I have also made a grid of 1 deg * 1 deg (both vector and raster) of the country. I want to calculate the area of each ...
0
votes
0answers
19 views

Grouping layers in QGIS? [duplicate]

I'm trying to group a large amount of layers together. They are a mix of Polygons and Points, I would like to create individual groups by the layer's name. Anyone have any ideas?
3
votes
2answers
77 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
32 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
0answers
26 views

Creating slippy map from large shapefiles?

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 ...
0
votes
0answers
42 views

Making QGIS custom form modal?

I have created a custom form for entering attribute values for newly added features / editing attribute values for existing features of a shape file. I chose the ui file as "Edit UI" and a python file ...
0
votes
0answers
14 views

How to use cx_Oracle db connection with OGR API

I am creating ogr datasource for oracle spatial using OCI connection in pyton code successfully. I can also get the layer from the datasource and I can add new features. But I am also using ...
4
votes
2answers
103 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
81 views

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

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 ...
3
votes
2answers
106 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
119 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
50 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
1answer
46 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
43 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
15 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
0answers
41 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
108 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 ...
0
votes
0answers
27 views

Is PyQt4 'drag and drop' functionality available in Qgis Plugins?

In Qgis 2.8, is it possible to use the PyQt4 drag and drop classes (dragEnterEvent, dropEvent) to interact with items from a qtreeview, in a Python Plugin? Is it possible to hook into the ...
1
vote
1answer
64 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 ...
1
vote
1answer
31 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
49 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
98 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
0answers
21 views

Where does GEOS Library gets installed QGis

Working on OS X 10.10, QGis 2.8 I want to install basemap. I installed QGis 2.8 which includes the GEOS and the PROJ4 library. In order to install basemap properly, I need to pinpoint it to the ...
1
vote
1answer
34 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
48 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
47 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
42 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, ...
2
votes
1answer
41 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
28 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
31 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
32 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
32 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 ...
2
votes
1answer
87 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 ...
1
vote
2answers
63 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
0answers
56 views

QGIS web client - mod_wsgi search - Windows

First of all i want to say that the QGIS web client works correctly. Now i want to get the search feature mod_wsgi running. I downloaded the correct mod_wsgi.whl from ...
0
votes
0answers
24 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
209 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
92 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 ...
1
vote
0answers
45 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
57 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
81 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
23 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 ...
1
vote
0answers
17 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
31 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
56 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
27 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
48 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 ...
0
votes
1answer
49 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 ...