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

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7
votes
4answers
2k views

How to create different diameter circles round points?

I want to map a tree survey. I am thinking that I will plot positional points of the trees and then add other data like tree type etc. to the attribute table later. Is there a way I can have an ...
11
votes
3answers
302 views

What is the most appropriate journal for publishing a paper about data collection with QGIS and mobile equipment?

I am a QGIS user, and a few months ago, we used QGIS on a PC Tablet to collect data on nesting birds on a cliff directly on the field. The principle is to have QGIS installed on a PC-Tablet with an ...
1
vote
1answer
122 views

What's the purpose of wms_metadata.xml and admin.sld?

I've installed QGIS Server and it works fine. But in /usr/lib/cgi-bin/ folder I've found 2 additional files - wms_metadata.xml and admin.sld. What is the purpose of these file? I've never used them.
10
votes
2answers
491 views

How to perform repetitive tasks in QGIS?

I am trying to do a treatment on many feature files, so I would like to automate it. In fact, I have one shapefile with the spatial distribution of some species, and one with vegetation type. I ...
2
votes
1answer
199 views

Why are some SVGs not displayed properly in print composer?

I am having weird problem with adding .svg to qgis print composer. I have done some smaller symbols before in inkscape and they work - however the latest one displayed itself as huge black square. I ...
4
votes
1answer
343 views

Is it possible to do spatial interpolation using points in a field?

I would like to use Quantum instead of ArcGIS to make field map but before, I need to know if its possible to do spatial interpolation with definited points in a field (ex. pH points). Is there a ...
1
vote
3answers
599 views

How to create one KML per polygon (from one Shapefile)?

I have a shapefile containing hundreds of polygons. I need to create a kml of each of the polygon. Is there any way that I may not have to deal each polygon individually and my polygon file may give ...
5
votes
1answer
312 views

QGis 1.8 fails to rotate point geometries with rule-based style

I have to do some visualizations in QGIS (1.8.0) and up to now I've been very happy with the new Dialog "Layer Properties -> Style", using the rotation-field to rotate Point-Geometries visualized by a ...
4
votes
1answer
119 views

QGIS printing to file, shading?

Hi I am not even sure how to ask this question and I have googled what i think is wrong with no success. When i create a map with different shadings on it, it looks perfect until it is wrote to pdf. ...
0
votes
1answer
180 views

Joining intersected polylines using rules based rendering [duplicate]

Possible Duplicate: Setting rendering order of line layers in QGIS I have trouble getting two intersecting polylines to look like they were joined at rendering. I am using rules based ...
6
votes
1answer
2k views

What is the best way to connect spatial data with attributes in Excel table?

I have many attributes which are stored in an Excel table. They refer to USA counties. I need to somehow connect those attributes to polygons in some format (don't know which is the best) and ...
2
votes
1answer
309 views

Problems with NAD27 projection in QGIS

I have some data that is in NAD27, but I am having a hard time displaying it in QGIS. I think that the problem is with the CRS. I cannot seem to find the correct NAD27 option. The closest one seems ...
4
votes
1answer
286 views

How can I avoid reprojection gaps when merging DEM rasters?

I have two raster DEMs in same resolution I want to bring together. I was using the merge-function in SAGA, GRASS and QGIS but I always get the following result: What do I need? Where could the ...
4
votes
1answer
1k views

Revealing the different layers of a shape file in QGIS

Shapefile I am referring to is 'NUTS_RG_03M_2010' which is together with several other Shapefiles available in a ZIP file on the Eurostat web site. the ZIP file the available map sets at Eurostat I ...
0
votes
0answers
203 views

How do you normalize a field in Qgis symbology?

I'm trying to normalize a field in symbology in Qgis but there is no normalization option like in Arc. I've tried to add a field to the attribute table and use the field calculator to do the ...
3
votes
2answers
188 views

How to modify two polygons which have common point and line at the one time

I would like to modify two polygon at the one time because these two data has same point and line. Is it possible?? In the present circumstance, I have to modify polygon one by one. First, I ...
1
vote
1answer
162 views

How to remove terracing from Civil3D GeoTIFF export?

I've received a GeoTIFF DEM that was exported from Civil3D and at every contour there is a distinct terrace created when I process an aspect or slope in QGIS with the GRASS plugins. I've looked ...
4
votes
1answer
158 views

Problem with custom projection definition in Qgis

I want to define a custom crs valid for Mexico. The context is that older cartography in Mexico is based on the NAD27 datum. I wanted to test the following proj4 string +proj=longlat +ellps=clrk66 ...
3
votes
0answers
829 views

How to join data from a CSV to a shapefile using QGIS

I'm new to GIS and new to StackedExchange. I need help joining a CSV of Accessibility data to a LSOA shapefile in QGIS. The process explained here does not work for me and I don't know why. The ...
3
votes
3answers
1k views

Auto-calculate field (area or formula)

I'm wondering if anyone has any insight into the potential to auto-calculate the value of a field, either area or distance (ideally) or a formula (based on the values of say 2 other fields, or an ...
2
votes
3answers
13k views

How to convert shape files (.shp) to Cad (.dwg ) format using Quantum Gis 1.7.0?

How to convert shape files to .dwg format using Quantum GIS 1.7.0 ? Thank you
2
votes
1answer
123 views

Can you change the location of .qgis from the home directory to another folder on Windows in QGIS1.8?

Is it possible to change the location of the .qgis folder to another location ( for example on a network drive H:\ ) in Windows?
1
vote
0answers
133 views

How do I fix this QGIS sextante error? NameError: name 'sextante' is not defined

A colleague of mine posted this the other day. We haven't got any nibbles yet and I wanted to elaborate on the issue. We are having trouble running the r.mapcalculator function and receive the error ...
1
vote
1answer
390 views

How to create layer from shapefile in QGIS?

I have a road network shapefile that I want to use to create multiple maps from it, each based on some selection of original shapefile. For example, I want to show all highways with some custom ...
0
votes
1answer
308 views

How can I find and fix broken raster metadata using QGIS?

I have a raster (TIFF) hillshade image that I would like to use in a mapping project. However, I'm having a hard time lining it up properly in QGIS. Through a series of investigations, I have ...
1
vote
1answer
697 views

How to create new columns in QGIS by writng Conditional query on other columns of attributes table

First of all, sorry, I couldn't phrase my question better. So I want to be able to add a new column in my attributes table, say B, and it's value should be 1 if Column A's value is 1 and 0 if Column ...
2
votes
2answers
83 views

How to 'trace' areas from the layer below?

I have some Ordnance Survey vector data for my local area. I want to create a new layer and on it 'trace' some of the areas, fields, verges etc from the layer below with the intention of then ...
0
votes
1answer
395 views

How do I add a Corel Draw map as .dxf file to QGIS and how do I georeference it?

I have a vector data map of Poland, which I exported from Corel Draw. I can display the map in QGIS. At first the boundaries and subdivisions are only displayed as lines, after saving the data as ...
1
vote
1answer
90 views

I have a .sid image but can't figure out the CRS

There is a .map file: OziExplorer Map Data File Version 2.2 Tiritir_2.sid C:\OziExplorer\Maps\Islands\Tiritir_2.sid 1 ,Map Code, Geodetic Datum 1949,WGS 84, 0.0000, 0.0000,WGS 84 Reserved 1 ...
0
votes
0answers
157 views

Qgis ,Area Management of Dealer Network - Analysis of Population versus dealer location and sales performance

I want to analyse a Dealers retail sales performance by location , measuring sales versus population in total and social class etc. I have the shape file for the population of Ireland which includes ...
1
vote
3answers
3k views

QGIS Raster Calculater Syntax

I am trying to use the raster calculator in QGIS to combine a number of rasters. I want to calculate a mean, this is easy: (raster_1@1 + raster_2@1 + raster_3@1) / 3 I then want to create a max. ...
1
vote
1answer
790 views

Create buffer-lines in QGIS alongside Vector lines

I am currently doing a map of a farm, to see which roads needs to be repaired. Those roads are either one sided fenced, on both sides fenced or not fenced at all. I want to make buffer lines around ...
0
votes
1answer
389 views

Error running mapserver export in quantum gis

I have a project in Quantum GIS that I need to export to a .map file using de plugin mapserver export. I fill all the forms but I get this error when running the app. Any ideas of what is ...
1
vote
1answer
379 views

Automatic bulk snapping with FOSS

I'm looking for a tool that would be able to automatically snap features closer than a given distance. Is there such a tool/plugin for QGIS/GRASS/OpenJump? Would it be possible to achieve that with ...
3
votes
3answers
493 views

Sorting polygons by latitude?

We have a set of polygons which we would like to sort and number according to their latitude. This will make it easier for local authorities to relate to the numbers of the objects. I have looked ...
2
votes
1answer
723 views

Output of QGIS raster clipper not as expected?

My goal is to clip a raster with a polygon in QGIS 1.8. Based on an article I read, this should be a pretty straightforward task. However, the output appears to be empty. The raster produced is the ...
1
vote
1answer
915 views

How to draw grid cells in QGIS?

I have one ASCII text file with eight columns. The first four provide the x-coordinates (e.g. longitude) of the four corners of a grid cell, while the last four provide the y-coordinates (e.g. ...
7
votes
2answers
1k views

How Can I Make QGIS Stop Blinking Every Time I Pan?

The way QGIS draws the canvas when panning is quite annoying. If I pan the map even a little bit everything goes blank for a second or two before the layers are drawn. It looks like this happens only ...
3
votes
1answer
82 views

Get rid of raster grid cells that are less than 1

I'm using QGIS to work with raster data. I have a raster dataset of a country where each grid cell is assigned a number 1-100. However, the raster is in the format of a rectangle based on the extent ...
2
votes
1answer
87 views

How to interpret the OSGeo4w software version under Advanced Install option?

When choosing to install QGIS Desktop using the OSGeo4w advanced install option, I noticed that there are what looks like ambiguous software versions to choose. For example, currently QGIS Desktop ...
1
vote
1answer
1k views

Wrong coordinates in data when projecting in world map (qgis) [duplicate]

Possible Duplicate: How to find the proper coordinate reference system with two sets of data using different measurements or too convert one system into another I'm fairly new to the GIS ...
5
votes
2answers
624 views

Spatial Analysis with Factors/Classifications

When doing analysis on spatial data with associated information that is numeric, it is possible to use techniques such as Kriging or Interpolation or Cluster Analysis to find out interesting ...
1
vote
0answers
308 views

How to handle/ avoid intersect errors when clipping the difference between two layers?

Using QGIS + Grass, I've added a shapefile of coastline and islands to my map. I then buffer this shapefile to create a coastal zone of a known width. At this stage the buffer consists of the ...
2
votes
1answer
1k views

How to apply a graduated renderer in pyQGIS?

Just trying to run the following code already given in the pyqgis cookbook to create graduated colors symbology (as in example with 2 classes) I define the source info for the shapefile but when I ...
1
vote
1answer
439 views

Why do I get 'KeyError: 0' when using Line Intersection tool?

I'm using Quantum GIS version 1.8.0-Lisboa and trying to create intersection point using Intersection tool. (Vector -> Analysis tools -> Line Intersections ) But when I do that for my shapefile, It ...
0
votes
1answer
2k views

How to convert a finished project in QGIS to PDF

I have finished my project and need to convert it into a PDF file. How can I do it?
1
vote
1answer
406 views

matching georeferenced jpg with GPS data in WGS84 [closed]

I have imported my georeferenced jpg which I believe (on the basis of metadata in xmml file) to be in the NZGD2000 TM coordinate system. metadata: Origin: 1.76759e+06,5.94938e+06 Pixel Size: ...
6
votes
1answer
780 views

How to label a lot of nearby points?

I am currently working with a lot of points of which every point has to be labeled. I am already using the "Easy Custom Labeling" tool to move the labels and create lines to connect points with ...
0
votes
0answers
969 views

How to resample a raster in QGIS?

I've got a boundary file that I would like to resample the raster file from a 30m grid to a 10m grid inside the boundary file. When I try and do it in Qgis or Grass all I get is one big raster cube ...
0
votes
2answers
732 views

Python module “shapely.wkb” missing

I am trying to follow a tutorial from here http://qgistips.spatialthoughts.com/2012/12/find-neighbor-polygons-in-layer-in-qgis.html#more I have downloaded the relevant python script and edited it as ...