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

learn more… | top users | synonyms

1
vote
0answers
57 views

How do I make vectorlayer with sql on PostGis via python code

I need to make a vectorLayer and fill with the SQL's results on PostGIS via python code. I'm working with python 2.7, QGIS 1.8 and PyQt 4.5 How do I it ? thanks
0
votes
0answers
39 views

QGIS adding points using decimal degrees [duplicate]

As duck blind permits are sold, we need to add the location using lat/long. we are working in ArcView now but would like to move to QGIS- Everything I was able to find seemed to deal with importing ...
4
votes
5answers
2k views

Display ESRI Shapefiles in a map in a browser. (Not in google maps)

I have a series of shapefiles that I need to render as a map on a webpage. I have an ASP.Net server, although I would prefer something that will work on Linux servers. I would like to find an easy to ...
4
votes
1answer
375 views

Can one expose variables to the Python console from a plugin in QGIS?

I have a QGIS plugin that performs a long-running operation, eventually producing and loading new shapefiles into QGIS. (I have this as a plugin rather than just a function that can be called from the ...
9
votes
1answer
1k views

How to create a customizabe table in QGIS Print Composer?

I would like to add a custom table to a map layout created in QGIS. I would like a fair bit of control over the look of the table (borders, background colours of the cells, etc.), and it appears that ...
0
votes
1answer
108 views

How to know the real size of grid? [duplicate]

Im working with QGIS. When dividing a map with a grid I set in the paramters X=0.1 and Y=0.1. Could someone please explain what does that mean? I mean would the map be divided into 100mx100m squares? ...
1
vote
2answers
427 views

QGIS:what does it do “snap gcp coordinates to background layers” in the Georeferencer plugin?

Maybe is too obvious, but I don't find any precise documentation about this checkbox in the georeferencer plugin.
1
vote
1answer
106 views

problem in merging adjacent address polygons in qgis

I am having 15 polygon shape files of a sub locality of a city that is having address in their attribute table. I want to merge these polygons based on the address in the attribute table?how can i do ...
1
vote
1answer
194 views

How to count number of stores per company per region?

I have two layers. One point layer and a Polygon layer. It is simple to count the points in the polygon layer by the "points in polygon" function. But I also need some more information of the point ...
0
votes
2answers
243 views

How to count record points within a given area (electoral district)? [duplicate]

New user to GIS and to QGis but experienced data user. I have shapefiles for a state legislative districts. I have a set of individual voter records that I have geocoded. What I'd like to do is ...
0
votes
1answer
105 views

Value Map Attributes to Multiple Files in QGIS

I am hoping someone can share a way that I can some what automatically (none manual) associate a pre-defined CSV file for use with multiple shapefiles as an attribute Value Map. I have a number (in ...
1
vote
0answers
178 views

QGIS merge rasters error

I've been trying to merge some raster tiles at work and I've been getting an error message saying I don't have the correct permissions. This works fine on my home pc. Any obvious reasons for this? ...
0
votes
0answers
56 views

Borderlines of states subdividing my GRID

![enter image description here][2]I just merged a map of a country with its states, so I went from having 1 feature (the whole country) to 32 features. Is there any way to have the borders of the ...
0
votes
1answer
46 views

What is the meaning of “MULTIPOLYGON EMPTY” Message?

I am trying to run ST_Intersection function. SELECT ST_AsText(ST_Intersection(ST_Point(42.729123082000058,-96.619302355999992), ST_Point(42.72899715300008,-96.619410439999967))) FROM clu_08aug; I am ...
3
votes
2answers
1k views

QGIS Zonal Statistics just gives 'NULL'

Seems like such a simple plugin, but it just won't work. I'm trying to run Zonal Statistics to find the mean value of a raster's pixels within the area of a vector polygon, but all it will give me is ...
1
vote
1answer
173 views

Dividing map into features (whole squares)

I'm using QGIS 1.8.0. I divided a map of a state with its municipalities into many features using a GRID (small squares), but instead of creating one ID per feature (one ID per square), it creates one ...
2
votes
1answer
2k views

Does QGIS run on Windows Surface with Win RT OS?

I was wondering if anyone has had any success running QGIS on the Windows Surface tablet? Specifically with the Windows RT OS.
2
votes
2answers
333 views

Convert ASCII Grid Colorized to Raster

I have an ASCII Grid file + .prj file and can visualize this in qGIS. I can colorize it by going to properties and using a Pseudocolor Ramp. However, I want to export this now as a TIFF / Raster. ...
1
vote
0answers
119 views

Problem with pie-charts when exporting them to an image file

I have 3 vector layers: a map of Europe and N.Africa, a line layer, and a point layer (on the top). I have created pie-charts over the points in QGIS 1.7.3, and on QGIS itself, they look fine. ...
1
vote
0answers
130 views

how to avoid Intersection of polygons via python code

i am using QGIS 1.8 and i can set the check box in Setting\Snapping Options "Snapping and Digitizing " dialog to avoid polygon intersections and enable topological editing but i am looking for a way ...
3
votes
1answer
163 views

Strange exposure of a PostGIS layer in QGIS after importing OSM data into a database

I've imported a osm layer into my postgres/postgis database. osm2pqsql -E 3857 -c -S /usr/share/osm2pgsql/default.style -H localhost -W -d landslide -U postgres oberpfalz-latest.osm.bz2 During the ...
1
vote
0answers
499 views

How to integrate .NET application in QGIS using Python?

In our company we have developed a .NET application that's now integrated with 3 different GIS platforms. Now we would like to make it work with QGIS but we need some help on getting started. I've ...
0
votes
1answer
90 views

Why isn't enabling on the fly projection reflected in raster? QGIS 1.8.0

I have imported a map from the Ordnance Survey Open Data website. It is a 50k Street View raster. I have also created a new shapefile layer in which I have created a polygon overlay for the raster ...
0
votes
3answers
321 views

Converting .kml to different projection in qgis not working

I have run into a slight problem it would seem. Yesterday I downloaded qgis in the hope that it could convert a .kml overlay of some administrative boundaries from EPSG:3857 (Google maps) to ...
1
vote
0answers
137 views

convert vector with multiple attributes to multiple rasters

I have a vector polygon feature with multiple attributes/fields. Ultimately, I want to convert it to a raster 'stack,' whereby each of the attributes/fields will be a different band of the raster ...
0
votes
1answer
75 views

Polygons Shrinking and Moving as if CRS Was Suddenly Out of Sync with Project

I long ago set the CRS for a linguistic geography project I'm working on involving Oklahoma data (EPSG:2836 - NAD83(HARN) / Oklahoma North), and I have been closely monitoring that the polygon ...
9
votes
5answers
2k views

Are there open source solutions for travel demand modelling?

I'm looking for open source tools for travel demand modelling (eg The four-step UTMS). Preferably in a GIS environment. That works well with Qgis, Grass and Postgis. My question is not related to ...
5
votes
1answer
875 views

Is it possible to open the attribute table using PyQgis?

is it possible to open an attribute table from the python console or through a python script in QGIS? Thanks!
1
vote
2answers
607 views

How does MYSQL accept the WKT representation of a polygon with holes?

I have a set of coordinates that creates a polygon with holes in it. I'm using qgis with mmqgis to extract. How does MYSQL accept the WKT representation of a polygon with holes? By holes I mean ...
2
votes
1answer
127 views

Why do edits made in attribute table not show in associated layer? QGIS 1.8.0

I have compiled a heat map layer to display over a background raster map. I discovered that the heat map layer was incorrectly positioned because I had made an error in the coordinate entry fields of ...
3
votes
1answer
262 views

Which Graduated Symbology to use in QGIS

I am trying to map demographics data for a county in the UK based upon a combination of Census data. I want to compare the the averages for the county alone to the averages of the UK as a whole and ...
0
votes
1answer
42 views

Matching items from two tables

Can I select items in one table by matching items from a duplicate column in another table in QGIS?
1
vote
1answer
718 views

AttributeError: 'QgsFields' object has no attribute 'itervalues'

First of all, the code which is below gives me the attribute names of a shapefile correctly if I use PyScripter IDE: from qgis.core import * from qgis.gui import * from PyQt4.QtCore import * from ...
1
vote
1answer
529 views

What is required to get OGR to work with SQL Server?

All, I've been having heaps of trouble getting OGR to connect to our SQL Server development environment. (read about it here and here) SQL Versions: 2008, 2012 OS's: Windows 7, Ubuntu 12.04 My ...
7
votes
4answers
2k views

What does the “service” box in the PostGIS connection dialog stand for?

Can sоmеbody explain me what to write in the "service" box when connecting to the local DB. QGIS Lisboa and Postgres are installed.
0
votes
1answer
220 views

QGIS Value Map Edit Widget with properties dependent on another field

I'm having a problems with Edit Widgets in QGIS. I'm working on a GIS Database for archaeological data, where every site is represented by a polygon. In the attributes there is a field for the era ...
0
votes
1answer
134 views

How to edit a table in GRASS?

How do I edit a table in GRASS? When importing a vector into GRASS from QGIS, all the attributes are lost and I need these to continue with my analysis.
3
votes
2answers
215 views

How to avoid the CRS Dialog when creating a vector layer memory?

I am trying to create a vector memory in a plugin. Basing on some examples,I was able to create a memory vector layer and to add it in QGis with : QgsMapLayer.instance().addMapLayer(myLayer,True) But ...
1
vote
2answers
507 views

How to use SEXTANTE in a script outside QGIS?

I´m trying to do some geoprocessing using the QGIS Sextante plugin outside of the QGIS application (and integrate it with different other libraries like arcpy, etc.). import sys, os from PyQt4.QtGui ...
1
vote
1answer
217 views

How to get Quantum GIS display a line or polygon feature created by Python package pyshp

I am not sure if I have discovered a regression, or if I have not enough sleep. While I manage to create shapefiles with point geometries with pyshp, line and polygon features don't show up in QGIS. ...
5
votes
3answers
5k views

How to compute flow direction and flow accumulation with Qgis?

Any one who had made flow direction and flow accumulation on raster data for filled evaluation model i Qgis? Which tool and plugins are necessary, i haven't been able to find any guidelines on Google
0
votes
0answers
129 views

How to convert a set of points to a polygon based on a specific field in QGIS

I am having a point shapefile that consists of a number of point sets. I need to convert these points to a polygon based on a particular field in attribute table say for example locality . How can i ...
0
votes
1answer
2k views

How to remove shapefile polygon vertex marker points in QGIS 1.8.0

I have created a shapefile layer and drawn a polygon to show the boundary of a woodland. How can I edit the polygon to remove the crosses that denote the intersection of two points on the boundary?
0
votes
1answer
333 views

Custom Form with QTDesigner: Combine signals and slots?

I dare to ask that question here and not in the programmers section, cause i'm actually not looking for a coding answer, but a solution through the QtDesigner GUI (if possible). Custom QT-forms ...
0
votes
1answer
615 views

how to make transparent layers with Google earth layer?

with your help, i solved most of my problems, but here is another one - i guess, a smaller issue... I managed to get Google earth layer, but when I add my GPS gpx files, are all hidden under the ...
1
vote
2answers
2k views

QGIS conversion of Microstation .DGN to .SHP?

I'm attempting to convert a .dgn file to .shp using QGIS. I'm reading that support is only provided for v7 microstation files, is this still the case? I've been using ogr2ogr -f "ESRI Shapefile" ...
3
votes
2answers
1k views

how to add orthophoto layer in qgis

I am not an advanced user, but I try to be oneday :) here is my issue: I have tracks (just waypoints) from my GPS in gpx format. I also have orthophoto pictures in tif format, that I would like to ...
0
votes
1answer
33 views

Is the Qspatialite 6.0.8 font for SQL free text supposed to be huge?

A week ago I upgraded my Qspatialite plugin in QGIS 1.8, which I frequently use in parallel with Spatialite_GUI, to get the best of both Sqlite worlds. I immediately noticed that my SQL free text ...
8
votes
4answers
7k views

How to digitize a raster automatically

I have a raster (.sid extension) file. I want to digitize roads automatically in ArcMap, QGIS..etc. Digitizing by hand would be too time consuming. How can i do this ? Thanks
0
votes
2answers
970 views

How to create a MultiLineString feature with a postgis layer in QGIS

I have troubles handling with MultiLineStrings in QGIS. I added the table where I defined a column as geometry(MultiLineString, 31468) as a postgis layer in QGIS. Now I want to create features with ...