Planet OSGeo

Equipo GeoTux: ¡GeoTux cumple 5 años!

Sun, 05 Feb 2012 23:53:34 +0000

Un breve resumen de los 5 años de GeoTux: Post más leídos por año y agradecimientos a colaboradores.

Saludos a todos nuestros usuarios, lectores y por supuesto a nuestro equipo. Hoy es un día especial para GeoTux. Hace 5 años estábamos lanzando este sitio web con todo el entusiasmo y la incertidumbre que solo pueden tener un par de jóvenes recién graduados.

Pueden estar seguros de que nuestra intención siempre ha sido compartir lo que conocemos. Eso si, a veces el tiempo no da para responder todas las inquietudes, además que ignoramos un montón de cosas.

A continuación un listado de los posts más leídos de cada año:

2007: Construcción de un visor de Shapefiles con herramientas libres (38.348 visitas)

2008: Comparación de clientes ligeros web para SIG (16.119 visitas)

2009: Comparación de clientes ligeros web para SIG v.2 (8.060 visitas)

2010: Algunas configuraciones básicas en p.mapper (FAQ) (8.884 visitas)

2011: Visor de capas PostGIS para pgAdmin 3 (6.202 visitas)

Gracias a todos los que han aportado parte de su tiempo y esfuerzo compartiendo conocimiento con esta comunidad. Gracias de manera especial a Samuel, Remy, Edward, Edwin, William, Juan Carlos, Jhonatan, Ricardo, Totolhua, Mavka, David, Jose Mario, Andrés, "delphins", Luciana, Sandra, Diego y Fernando. En algún momento nos han colaborado en diversas tareas y secciones dándole más diversidad y vida a este sitio web.

Si apenas llegas y quieres conocer más de GeoTux, te recomendamos leer la entrevista del Observatorio Iberoamericano de Ciudadanía Digital: http://geotux.tuxfamily.org/index.php/es/component/k2/item/290-entrevista-observatorio-iberoamericano-ciudadania-digital-a-geotux

Finalmente, queremos invitar a todos nuestros usuarios a comentarnos cuál ha sido su experiencia con GeoTux. Como…

Sean Gillies: Geoprocessing for humans: pygp

sgillies@frii.com (Sean Gillies) — Sun, 05 Feb 2012 16:45:23 +0000

I'm not the only one simplifying terrible Python APIs in the geospatial world. Yesterday, I ran across a blog post about software named pygp. Very much about ArcGIS records and fields, it models data differently than Fiona does but similarly eliminates a lot of boilerplate and provides simple access to all coordinates of a record's shape field.

def example_geometry(path):
    """
    Example showing use of Geometry helper class that does the heavy lifting
    on the geometry object and returns something quite similar to WKT/GeoJSON

    Structure is simple, a tuple of tuple of Point objects, very similar to
    Avenue days of geometry and WKT MultiLineString etc.
    (((0, 498266, 6100519, None, None), (0, 499775, 6100281, None, None),
      (0, 500224, 6098694, None, None), (0, 499616, 6097662, None, None),
      (0, 498346, 6096789, None, None)))

    :param path: Workspace Path
    :type path: str
    """
    feature_class = FeatureClass(osjoin(path, POLYGON))
    for srow in feature_class.search():
        print srow.get_value(
            feature_class.shape_field_name).as_tuple()

# End example_geometry function

I don't know whether pygp has eliminated the need to count references to cursors and records or just omitted

del feature_class

from the example. I'd have looked in the code, but I couldn't find a link. I bet a lot of people would love to see it on GitHub.

Equipo GeoTux: Consola SQL para el plugin de pgAdmin: PostGIS viewer

Sat, 04 Feb 2012 09:22:48 +0000

He agregado una consola de comandos SQL al visor de capas PostGIS de pgAdmin. La consola permite ejecutar consultas SQL sobre datos de PostGIS para filtrarlos o ejecutar funciones espaciales sobre ellos.

For English click here.

El constructor de consultas incluído en un post anterior puede ser más complejo de lo requerido, especialemente cuando lo único que queremos hacer es ejecutar una consulta SQL simple. Por esto he agregado el plugin de QGIS Fast SQL Layer, el cual permite escribir la consulta en una consola básica.

¿Qué es Fast SQL Layer?

Fast SQL Layer es un plugin de QGIS escrito por Pablo T. Carreira para ejecutar consultas SQL para datos elmacenados en PostGIS y SpatiaLite. Viene con su propio resaltado de sintaxis, facilitando un poco el proceso. He editado un poco el plugin para integrarlo con el visor de capas PostGIS para pgAdmin.

Prerrequisitos

Python, PyQt4, PyQGIS, libqt4-sql-psql, psycopg2 y pygments (para el constructor de consultas).

Cómo instalar prerrequisitos en Windows: Ver este post, además se requiere instalar psycopg2 y pygments desde OSGeo4W.

Cómo instalar prerrequisitos in Ubuntu/Linux: Para QGIS, ver la página oficial de descargas. Para los demás programas/ librerías usar apt-get o Synaptic.

Instalación

Después de instalar los prerrequisitos, solo se requiere extraer un archivo ZIP (descargar el archivo zip) en la ruta adecuada (en Windows: C:/Archivos de programa/PostgreSQL/8.4/bin/ mientras que en Ubuntu/Linux: /usr/bin/) y editar el archivo plugins.ini de pgAdmin.

En Ubuntu/Linux se requiere el comando sudo para extraer y definir permisos 755 sobre los archivos extraidos, de esta manera:

  sudo unzip postgis_viewer.zip -d /usr/bin/ 
  sudo chmod 755 /usr/bin/postgis_viewer/ -R

Adicionalmente, copiar las siguientes líneas a /usr/share/pgadmin3/plugins.ini (si el archivo no existe, debe ser creado):

…

Paolo Corti: Python for geospatial developers

Fri, 03 Feb 2012 16:15:00 +0000

There is a recurring question at GIS mailing lists, forum and at some extent in my mailbox: what is the best way to master Python for developing geospatial applications?I myself had this question far away in 2006 when I started switching from proprietarysoftware to Open Source, and had identified in Python the way to go.In this post I will try to quickly summarize what is the best way to go in my opinion.If you are completely new to Python, first things to check out, are some very basic and popular resources, like these ones:the official Python tutorialthe "Dive into Python...

Slashgeo (FOSS articles): FOSSGIS Brasil Magazine #4

Thu, 02 Feb 2012 23:20:53 +0000

We are very proud to announce the release of the 4th edition of FOSSGIS Brasil Magazine.

In this 2012 1st issue, the cover section addresses Medatada theme, which deserves special attention of any professional who works with geospatial data.

This 4th edition of FOSSGIS Brasil was built with the effort of the GIS community, including international contributions. Consering this, be sure to check the interview with Jeroen Ticheler, founder and CEO at Geonetwork project, and also the text written for three of the most important contributors of the gvSIG association, talking about the new development model for the project of the robust gvSIG GIS suite.

This year, greatest desire for us at FOSSGIS Brasil team is to continue doing what we have been doing in 2011: To georreference knownledgment

Link to download: http://bit.ly/zFKS3b

Sincerely,
The FOSSGIS Brasil team
http://www.fossgisbrasil.com.br

Slashgeo (FOSS articles): SpatiaLite 3.0 Released with Excel Spreadsheets Support

Thu, 02 Feb 2012 19:25:43 +0000

I failed to find much information about it, but SpatiaLite, the geospatial version of SQLite, reached version 3.0 about a month ago. Anyone knows where to find release notes? I find also funny that on SpatiaLite homepage, it is clearly stated that spatial is not special! :-) Yes, I'll share a followup to my previous entry on the topic (thanks for your feedback!).

On the SpatiaLite topic, here's a blog entry named Spatialite and Excel on talking terms: "The recent stable version of Spatialite, 3.0, supports linking to and importing Excel spreadsheet tables. Read on to see how it’s done. The developers of spatialite have added a driver for *.xls files (thru the FreeXL library ). You can either link to, or import a single sheet from an Excel file [...]"

Tim Sutton: Publishing multiple projects with QGIS Server

Thu, 02 Feb 2012 14:04:47 +0000

You know the drill right? You just made a beautiful map for your boss using QGIS Server. Then he walks into your office and says ‘Kiepie, I need another one in a different CRS’. Your heart drops in your chest and your jaw drops to the desk. You can’t do that using QGIS without publishing [...]

Slashgeo (FOSS articles): OGRS2012 :: CALL FOR PAPERS - Open Source Geospatial Research and Education Symposium

Thu, 02 Feb 2012 13:28:33 +0000

----------------------------------------------------------------------------
OGRS2012 :: CALL FOR PAPERS
Open Source Geospatial Research and Education Symposium

October 24 – 26, 2012 in Yverdon-les-Bains, Switzerland
Hosted by School of Business and Engineering Vaud (HEIG-VD)

Website: http://www.ogrs2012.org
Contact: cfp@ogrs2012.org

Notice, PDF version of this call is available here : http://cfp.ogrs2012.org.
-----------------------------------------------------------------------------

(our apologies for cross-postings)
Dear colleagues,

The Open Source Geospatial Research and Education Symposium (OGRS) is a meeting dedicated to exchanging ideas on development and use of open source geospatial software in both research and education.

Motivated by the inaugural symposium in Nantes, France, OGRS2012 will be held from October 24 – 26, 2012 in Yverdon-les-Bains, Switzerland. The symposium is hosted and organized by the School of Business and Engineering Vaud (HEIG-VD), in partnership with EPFL Lausanne, University of Lausanne, University of Geneva, which are all academic institutions in Western Switzerland, and the Institute for Research on Urban Sciences and Techniques in France.

The main goals are:
- to build a panel of new scientific research and education practices using and contributing to open source initiatives in the geospatial fields;
- to discuss a framework and highlight a rationale about geospatial open source technology usage in research and education activities;
- to provide an innovation platform to network and develop ideas for future collaborative work between academia – from research to education – and other actors of the field (associations, foundations, local authorities, industry etc.).

For more details, visit the overview page on the website.

Keynote speakers :
- Luc Anselin, Director, Regents' Professor and Walter Isard Chair at School of Geographical Sciences and Urban Planning, College of Liberal Arts and Sciences and Director at GeoDa Center for Geospatial Analysis and Computation, Arizona State University;
- Gérard Hégron, Scientific Director in charge of sustainable city at IFSTTAR (French Institute of Science and Technology for Transport, Planning and Networks);
- Helena Mitasova, Associate Professor at Department of Marine, Earth and Atmospheric Sciences, North Carolina State University;
- Robert Weibel, Professor of Geographical Information Science at Department of Geography, University of Zürich.

Submission :
The symposium will integrate several opportunities for presenting : oral presentations, workshops, posters and discussion groups. To participate in any of these opportunities, authors are invited to submit an extended abstract (1000 to 1500 words, references and keywords excluded) through the conference website. The official language is English.

The international scientific advisory board will review and select abstracts for inclusion in the symposium and publication in the symposium proceedings. A subset of contributions will be invited to submit full papers for possible publication in a special issue of the Journal of Spatial Information Sciences (JOSIS), pending a peer review of full papers.

For more details on how to submit a contribution, please visit the call for papers page on the website : http://cfp.ogrs2012.org.

Important dates :
- submission deadline for abstracts is May 28, 2012.
- authors will be notified by June 30, 2012 on program inclusion and selection for JOSIS submission
- deadline to submit full papers is September 30, 2012.

Best regards,
OGRS2012 program committee

OpenGeo Blog: It goes up to 2.0

Wed, 01 Feb 2012 18:59:18 +0000

Maybe someday PostGIS will go to 11, but for now, we’re still shooting for 2, point oh. And happily we are getting closer and closer. We have moved to a weekly schedule of alpha releases (this week was alpha3) and have started cleaning down the list of tickets against the 2.0 milestone.

Last month, much of the time spent by me and Sandro Santilli on PostGIS 2.0 preparation was funded by the Humanitarian Information Unit of the US Department of State. So, from the PostGIS development team, and the PostGIS community in general: thanks, HIU! Why is HIU funding PostGIS? Because the kinds of tools that HIU and its partners use for humanitarian response are backed by PostGIS, and they want to see those tools get better. Funding PostGIS development is an economical way to simultaneously raise the capabilities of a whole ecosystem of tools in HIU’s space.

Prodevelop: ¡Aventura Oceánica vuelve a la carga!

Wed, 01 Feb 2012 15:04:54 +0000

Kike y José Carlos vuelven a subirse al Bahari para retomar la Aventura Oceánica, tras un año de parón tras partir el mástil poco después de cruzar el cabo de hornos. El sábado pasado salieron de Valparaíso (Chile) hacia la Isla de Pascua. Desde Prodevelop les deseamos toda la suerte para que sigan con su impresionante viaje alrededor del mundo, esta vez en pleno Pacífico.

Puedes seguir su itinerario día a día desde su web gracias a un sencillo desarrollo que llevamos a cabo en Prodevelop hace ya más de dos años utilizando PostgreSQL/PostGIS, Spring y Java Mail en el servidor y Open Layers en la capa de presentación.

Fernando Quadro: Lançada a 4a edição da Revista FOSSGIS Brasil

Wed, 01 Feb 2012 14:16:56 +0000

Caros Leitores,

Temos o prazer de anunciar o lançamento do 4°. número da Revista FOSSGIS Brasil. Nesta primeira edição de 2012 a série de capa aborda o tema Metadados, um assunto que merece a atenção especial de todos os que trabalham com dados geográficos. Ao ler os artigos você entenderá o que são metadados e sua relevância no contexto das Geotecnologias. Como complemento à teoria disponibilizamos um tutorial sobre como editar metadados em ambiente SIG Open Source.

Na coluna Desktop GIS apresentamos detalhes sobre o software Spring que nos ajudam a entender por que este projeto brasileiro tem-se mostrado um grande sucesso na área de tecnologia para SIG. Os usuários de ferramentas Mobile gostarão especialmente de ler a matéria sobre o OSM Tracker. Neste número há também um artigo muito interessante que explica como customizar o software Kosmo para aplicações portáteis.

A edição 4 da FOSSGIS Brasil contou com a colaboração da comunidade internacional. Neste sentido não deixe de conferir a entrevista de Jeroen Ticheler, fundador e presidente do projeto Geonetwork opensource e o artigo escrito por três personalidades de destaque da Associação gvSIG falando um pouco sobre o novo modelo de desenvolvimento do projeto deste robusto software para Sistemas de Informação Geográfica.

Para fazer download desta edição, basta acessar o link:

http://fossgisbrasil.com.br/download/

Este ano o desejo de todos que fazem parte da Equipe FOSSGIS Brasil é continuar Georreferenciando o Conhecimento!

Atenciosamente,

Equipe FOSSGIS Brasil

Posts Relacionados

Slashgeo (FOSS articles): Batch Geonews: 180,000 Free OrbView-3 Scenes, Car AR Driving, PostGISonline, Bing Maps Updates, Autodesk and Pitney Bowes Alliance, Obesity and Car Travel, and much much more

Wed, 01 Feb 2012 13:48:01 +0000

This batch mode edition is unusually long. It covers the past month and a bit more. Yes, that's way too much and I won't try to repeat the experience ;-) Here's what I considered pertinent enough to share with you. Exceptionally, in some cases I haven't gave attribution to the source of the news, thank you for your comprehension.

On the geospatial open source front:

I just recently became aware of PostGISonline, a site for testing and learning spatial SQL
You can now create and manipulate SLD (the OGC Styled Layer Descriptor standard) in Python with python-sld
Via the AGISRS list, I learned about OpenQuake.org, for calculating seismic hazard and risk at any scale, which of course ingest geospatial data and outputs maps
Here's WherePost.ca, which crowdsources the location of mailboxes and post offices for Canada
Here's the Switch2OSM website promoting OpenStreetMap, OpenStreetMap might go indoor too
Still on the OSM topic, V1 shares an entry on the use of OpenStreetMap data in agriculture
Here's an entry on the future of GeoCouch and CouchDB
GeoServer gets database-level security
There's now a plugin to run Python scripts in QGIS
Here's about improvements to the QGIS rule-based rendering
On a similar topic, here's a guide to beautiful reliefs in QGIS
Did you know you can add Google Maps, OSM, and Bing Maps directly in QGIS? You can via the OpenLayers plugin - hey, there's even a Profile plugin
There's an updated book published by Gary Sherman, now named The Geospatial Desktop , subtitled Open source GIS and mapping
GEOS 3.3.2 has been released

On the Esri front:

Mandown shares how to convert GPX files to Features using ArcGIS 10
From the same source, Learn The Basics Of Working With The ArcGIS Runtime SDK For Android
There were updates to ArcGIS for SharePoint, ArcGIS Mobile and to the ArcGIS API for Windows Phone
James and SS talks about ArcGIS Online as the Esri Content Management System

On the Microsoft front:

Microsoft announced a few new Bing Maps features, such as traffic incidents and find near route
They announced the Bing Maps Windows Presentation Foundation (WPF) Control v1
There's new Bing Maps V7 modules too along with a new routing engine
James Fee shares an interesting entry named Bing Maps gets Nokia Brand and Possibly the Boot

On the remote sensing front:

This is pretty interesting to many: SS shares an entry named USGS Now Offers OrbView-3 High-Resolution Images for Free, 180,000 scenes at 1m spatial resolution available
China launched their first high-resolution remote sensing satellite, Ziyuan I-02C
Slashdot discussed the newly released version of Blue Marble high definition (and beautiful) satellite image of the Earth from the Suomi NPP satellite
Slashdot is running a story named Who's Flying Those Drones? FAA Won't Say and related, O'Reilly mentions OpenPilot, open source UAV with cameras
And another named Launch Your Own Nanosatellite Into Space

On the GNSS / GPS front:

It's coming, car makers are preparing for augmented reality driving
Not exactly GPS but via radio-tagging, see the nice and short video of whale 3D paths in the ocean
Slashdot is also discussing a story named New Mexico Is Stretching, GPS Reveals
MapQuest launched an html5 app-like site for Android and iPhone for using MapQuest

In the miscellaneous category:

The 7 geo predictions for 2012 of Cédric are interesting
Microsoft's Flight Simulator, renamed Flight, will be available for free next Spring, with paid extra content
We never mentioned it before, but now Indiemapper is free, it "helps you make static, thematic maps from geographic data by bringing the best of traditional cartographic design to internet map-making."
SS mentions the new alliance between Autodesk and Pitney Bowes, APB also discuss this new relationship
SS also shares an entry named Safe Software’s Expanded Role as a Conduit Between Sensors and Systems
The U.S. EPA in their Locations Challenge introduced a crowdsourcing project of georeferenced photos of environmental problems
Slashdot ran a discussion on assembling your own 3D printer
The OGC shared a summary of the Eye on Earth Summit held in December
Another OGC entry was named Status of the OGC's Water Resource Activities
DM shares an article named GIS Adoption and Use on College Campuses: An End-of-Year Review and Look Ahead to 2012
The GEB mentions a new 3D San Francisco website
I found interesting the possibility of a .data TLD
A new free iPad app: GeoViewer from LizardTech, supports MrSID format and more
It's been a while since we mentioned them, GISCorps were recently in 7 countries, including Libya

In the maps category:

APB summarizes this: Comparing Maps of Obesity and Car Travel
Here's an entry on cleanly using symbols on maps
Here's U.S. routes as a subway map and the U.S. National Wind Energy Map
Fox News shared a map with missing or wrongly placed countries
TMR shares an obligatory animated map of rising global temperatures since 1880

Even Rouault: Welcome to the 200th GDAL/OGR driver !

noreply@blogger.com (Even Rouault) — Wed, 01 Feb 2012 06:58:44 +0000

A few hours ago, I merged into the GDAL/OGR source tree the ElasticSearch driver, which was contributed by Adam Estrada. According to the driver testing status page, it happens to be the 200^th driver !

To be honest, a few of them have been retired over the years (mainly because being deprecated by rewritten versions), so even if you try to enable all possible drivers, you won't reach 200. But you can get close : my build currently includes 124 GDAL drivers and 60 OGR drivers.

This 200th driver is a bit particular, because it is a write-only driver, whereas 99% of drivers are generally read-only or read-write.

What about the other new drivers that have been committed in GDAL trunk since 1.9.0 release ?

As far as GDAL drivers are concerned, there is a driver to read MBTiles that Dane Springmeyer already blogged about.

More recently, new spreadsheet formats have also made their way into OGR. Namely the ODS driver and the XLSX driver that respectively handle files in the Open Document Spreadsheet format, used by applications like OpenOffice / LibreOffice and Office Open XML, generated by applications like Microsoft Office 2007 and later versions. If you are wondering about the fate of the older XLS format, a XLS driver is already included in GDAL/OGR 1.9.0, provided your GDAL build links against the FreeXL library written by Alessandro Furieri, the main author of libspatialite.

The ODS and XLSX drivers have very similar capabilities and source code, which is not surprising, because the technologies behind the 2 formats are the same : XML files in a ZIP container (if you don't believe me, you can just try renaming your .ods and .xlsx files into .zip, and open them with your favorite ZIP browser).

Writing the drivers was surprisingly simpler that I initially expected. In order to retrieve cell values, you just need to extract a few XML elements. From a developer point of view, the award of the most simple format to read goes to ODS with a nice separation between semantics and styling, and only one file (content.xml) to parse. XLSX is a bit more complicated to analyze because you have to read at least 4 different files (workbook.xml, sharedStrings.xml, styles.xml and a file for each sheet in the spreadsheet) and you need to understand some of the styling information to make the difference between a regular numeric value and a date.

Those drivers also support creating ODS and XLSX files. Caution: only raw values will be written. No fancy styling ! Update of existing files is also supported. But this uses the same serialization mechanism as the one used to create a new file, so be aware than existing formulas, charts, drawings, etc... will be lost.

Not detailed in the documentation page of the drivers, if you need some form of spatial support with those formats, you can combine them with the use of OGR VRT, in particular the GeometryField element, to be able to use column(s) of your spreadsheet as geometry columns.

The good news is that those 2 new drivers don't have any other dependency to third-party libraries than the Expat XML-parser library, that is also already used by many others drivers in GDAL and that most binary distributions of GDAL will link against. Typically, you will find them ready-to-use in Tamas Szekeres automated Windows daily builds (fetch the -development packages at the top of the first table to get builds corresponding to the latest GDAL trunk version).

Testing is highly encouraged, as well as reporting of issues you might run into.

In particular, interpreting spreadsheets that make use of formulas can be a tricky point. Depending on the application that writes the files, the result of the evaluation of formulas might or might not be written in the file. The ODS and XLSX drivers will use the result of the evaluation if available. In the case it is missing, I've plugged into the ODS driver a simple formula evaluator that can understand and evaluate a restricted set of functions (readers interested in the details will find the detailed list in the first enumeration of the ods_formula.h header file). Based on my testing, OpenOffice always writes the evaluation of formulas, whereas the OpenOffice export of Google Spreadsheet documents will not.

For now, there is nothing equivalent implemented in the XLSX driver, as I have not access to a sufficiently representative set of files, and it is not yet clear if it is a common practice or not to have non-evaluated formulas for that format. The good news is that, should the need arise, the first tests would tend to show that it should be possible to extend the ODS formula evaluator with just a few changes, so it can also understand XLSX formulas.

OTB Team: Release of OTB 3.12 and Monteverdi 1.10

Tue, 31 Jan 2012 17:01:42 +0000

Dear all,

CNES is proud to announce the release of Orfeo ToolBox 3.12, codename Πλειάδες.

After its sucessful launch on the 17th of December 2011, and while still in its comissing phase, Pleiades is already sending us beautiful images. This new release, and especially the JPEG2000 support part, has been tested against real Pleiades images kindly provided by the comisioning team.

There are exciting new stuff in all corners of the library. Some of the notable changes in this release are:

Large JPEG2000 file (Pleiades-like) support and Pleiades metadata handling in OTB (more information here)
Efficient JPEG2000 visualisation and ROI decompression tools in Monteverdi
Revamp of otb applications in a generic and scalable framework (more information here) : launch applications from Command-Line, from an auto-generated QT GUI, from python, from within QGis …
Lots of new algorithms : Dimensionality Reduction (ICA, PCA, NAPCA, MNF, MAF…), change detection (MAD), Hyperspectral Unmixing, elevation map from stereo data, compare segmentation with a ground truth (Hoover) …
And as usual a lot of bug fixes…

Note that the OTB Software Guide is now 658 pages long, and that we also provide the “Orfeo ToolBox Cookbook, a guide for non-developers”, which gives an insight on how to use Monteverdi and the OTB applications, and also contains the complete reference documentation of the OTB applications. This guide is now 158 pages long.

There are a lot more new things in this release ! For more information, please read the complete release note available here. The source packages for OTB (Library 3.12, Applications 3.12, Monteverdi 1.10) are available on Sourceforge as usual. For our Ubuntu (10.4,10.10, 11.4 and 11.11) users the new version is available for update through you favorite package manager software. OpenSuse and CentOS packages will be available soon. For MS-Windows users, there are also a binary auto-install packages available for Monteverdi, new OTB applications and OTB-Wrapping! For Mac OS X users, an Apple Disk Image (DMG) is available for Monteverdi and also a new OTB MacPort.

All the details related to the installation of these binary packages can be found on the download page.

Best regards,

Manuel GRIZONNET, on behalf of OTB development team.

GeoTools Team: GeoTools considering a switch to Git

noreply@blogger.com (Andrea Aime) — Tue, 31 Jan 2012 15:55:47 +0000

Hi all,

the GeoTools developers have been working, so far, with Subversion as the main version control system. However various core developers have been using Git as a SVN client for quite some time so far, and an official mirror of Geotools, automatically kept in synch with Subversion, is already available on GitHub.

We are now considering switching permantently from Subversion to Git, meaning the Subversion repository will eventually be abandoned and only the Git official central repo will be kept up to date.

Before making such move we'd like to hear from the users community, please take one minute to share your opinion about the switch to Git:

Click here to go to the poll.

gvSIG Team: New gvSIG courses in English, Spanish and Italian on the gvSIG-Training platform available

Tue, 31 Jan 2012 08:47:59 +0000

[Más abajo en español]

The gvSIG-Training e-Learning platform opens its registration period for the first courses in 2012. These courses, that are included in the Certification Program of the gvSIG Association, are the following:

-Restricted Registration, which registration period starts on January 30th:

1st edition of the “gvSIG for users course” in English. Duration: 10 weeks. Starts: 07 May 2012. gvSIG certification program: 90 Credits.
2nd edition of the “gvSIG for users course” in Italian. Duration: 10 weeks. Starts: 02 April 2012. gvSIG certification program: 90 Credits.
3rd edition of the “gvSIG for users course” in Spanish. Duration: 10 weeks. Starts: 26 March 2012. gvSIG certification program: 90 Credits.
2nd edition of the “Advanced Geoprocessing: Sextante on gvSIG” course in Spanish. Duration: 10 weeks. Starts: 05 March 2012. gvSIG certification program: 30 Credits.
1st edition of the “Advanced Geoprocessing: GGL libraries on gvSIG” course in Spanish. Duration: 10 weeks. Starts: 26 March 2012. gvSIG certification program: 30 Credits.
1st edition of the “3D extension of gvSIG for users” course in Spanish. Duration: 2 weeks. Starts: 23 April 2012. gvSIG certification program: 30 Credits.

- Open Registration, which registration period starts on February 6th:

1st edition “Navtable extension and normalization of tables on gvSIG” course in Spanish. Duration: 1 week. gvSIG certification program: 10 Credits.
1st edition “Network Analysis extension on gvSIG” course in Spanish. Duration: 2 weeks. gvSIG certification program: 20 Credits.
1st edition “OGC Services Publishing Extension on gvSIG” course in Spanish. Duration: 1 week. gvSIG certification program: 20 Credits.
1st edition “PostGis for users Basic course” in Spanish. Duration: 3 weeks. gvSIG certification program: 40 Credits.

If you participate in any of these courses, you get credits of the gvSIG certification program, that allows you to opt for the “gvSIG User” and “Expert gvSIG User” certification [1]; and at the same time you contribute to the sustainability of the gvSIG project.

For more information, you can visit our platform, http://www.gvsig-training.com, or write us to the next e-mail addresses: inscripciones@gvsig-training.com; info@gvsig-training.com

[1] http://www.gvsig.com/services/certification

Nuevos cursos de gvSIG en español, inglés e italiano disponibles en la plataforma gvSIG-Training

La Plataforma de Capacitación a Distancia gvSIG-Training anuncia que el proceso de inscripciones del primer corte del 2012 para los siguientes cursos, que forman parte de la oferta del Programa de Certificación de la Asociación gvSIG, da inicio según se detalla a continuación:

- En la modalidad de Matrícula Restringida, con inscripciones abiertas a partir del próximo 30 de enero:

3a edición “gvSIG para usuarios en Español”. Duración: 10 semanas. Inicia: 26/03/2012. Programa de certificaciones gvSIG: 90 Créditos.
2a edición “Geoprocesamiento Avanzado: Sextante sobre gvSIG” en Español. Duración: 10 Semanas. Inicia: 05/03/2012. Programa de certificaciones gvSIG: 30 Créditos.
2a edición “gvSIG para usuarios en Italiano”. Duración: 10 semanas. Inicia: 02/04/2012. Programa de certificaciones gvSIG: 90 Créditos.
1a Edición “gvSIG para usuarios en Inglés”. Duración: 10 semanas. Inicia: 07/05/2012. Programa de certificaciones gvSIG: 90 Créditos.
1a edición “Geoprocesamiento Avanzado: Librerías GGL sobre gvSIG en Español”. Duración: 10 Semanas. Inicia: 26/03/2012. Programa de certificaciones de gvSIG: 30 Créditos.
1a Edición “Extensión 3D de gvSIG para usuarios en Español”. Duración: 2 semanas. Inicia: 23/04/2012. Programa de certificaciones gvSIG: 30 créditos.

- En la modalidad de Matrícula Abierta, con inscripciones abiertas a partir del próximo 6 de Febrero:

1a Edición “Extensión de Navtable y normalización de tablas de gvSIG en Español”. Duración: 1 semana. Programa de certificaciones gvSIG: 10 créditos.
1a Edición “Extensión de Análisis de Redes de gvSIG en Español”. Duración: 2 semanas. Programa de certificaciones gvSIG: 20 Créditos.
1a edición “Extensión de publicación de servicios OGC de gvSIG en español”. Duración: 1 semana. Programa de certificaciones gvSIG: 20 créditos.
1a Edición “PostGis para usuarios Básico en Español”. Duración: 3 semanas. Programa de certificaciones gvSIG: 40 créditos.

Al participar en cualquiera de estos cursos obtienes créditos del programa de certificación gvSIG que te permite optar a la certificación “gvSIG Usuario” y “gvSIG Usuario Experto” [1]; al mismo tiempo que contribuyes al sostenimiento del proyecto gvSIG.

Para mayor información visita nuestra plataforma http://www.gvsig-training.com o escríbenos a la siguientes direcciones de correo electrónico: inscripciones@gvsig-training.com; info@gvsig-training.com

[1] http://www.gvsig.com/servicios/certificacion/certificacion

Filed under: opinion

gvSIG Team: DiSiD nuevo socio de la Asociación gvSIG

Mon, 30 Jan 2012 18:02:33 +0000

Una de las noticias que más nos gusta dar es el salto de una de las empresas colaboradoras a empresa de pleno derecho de la Asociación gvSIG.

En el 2012 DiSiD deja de ser empresa colaboradora para constituirse en socio de pleno derecho de la Asociación gvSIG. Tras un periodo de incubación durante el que se han desarrollado diversos proyectos conjuntamente, ambas partes hemos constatado la coincidencia absoluta en el modelo de negocio del Software Libre que interpreta la Asociación gvSIG.

La incorporación de nuevos socios es siempre un hecho significativo, pues refuerza nuestro modelo de producción, permitiéndonos avanzar en la sostenibilidad del proyecto siendo fieles a sus parámetros de colaboración y solidaridad en lo que denominamos una nueva ética de los negocios.

Para los que no la conozcáis, DiSiD es una empresa de ingeniería informática especializada en tecnología Java de código abierto, con diversas lineas de negocio como: desarrollo de portales corporativos con gestión de contenidos digitales, soluciones de tiendas virtuales y comercio electrónico, consultoría tecnológica, formación, desarrollo de aplicaciones a medida y sistemas de información geográfica.

Dentro de esta última linea lleva varios años como colaborador de la Asociación gvSIG, participando activamente en el desarrollo y arquitectura software de gvSIG, haciendo especial hincapié en la versión 2.0. Participa también en otros desarrollos basados en gvSIG, como el proyecto de llevar gvSIG a la aulas de primaria y secundaria -gvSIG Educa/Batoví- que se está desarrollando en colaboración con el Gobierno de Uruguay en el marco del Plan Ceibal y del que esperamos en breve poder anunciar una primera versión oficial.

En su apuesta por proyectos de código abierto, DiSiD es el principal impulsor del proyecto gvNIX junto con la Conselleria de Infraestructuras, Transportes y Medio Ambiente. Dicho proyecto consiste en un framework Java de desarrollo rápido de aplicaciones empresariales.

Participa activamente también en otros proyectos de software libre como: Spring Roo, Spring Framework, Apache Ofbiz, Liferay, etc.

¡Bienvenidos a la Asociación gvSIG!

Filed under: Business, gvSIG Association, spanish

Simone Giannecchini: Developer's Corner: Introducing Database Level Security in GeoServer

noreply@blogger.com (Andrea Aime) — Mon, 30 Jan 2012 15:51:23 +0000

During our work we support manu GeoServer Enterprise installations which pull data from a spatial database of some sort, normally via a connection pool, a tool that keeps database connections around so that we don't have to open and close them at every request (something that could be very expensive).

The pool accesses the database via a shared user, that all GeoServer requests end up using. Some requests only require data reading (WMS GetMap), others modify data (WFS Transaction), some even create new tables (RESTConfig data uploading for example).

The pool user must be able to perform all and any of the operations that GeoServer needs, meaning that more often than not it has very wide powers of what it can do on the database.

GeoServer built in security, as well as extensions such as GeoRepository, allow to control what specific users can do and shield the database from security issues.

However in some enviroment the preferred security management policy is to have security restrictions operate at the database level instead, with the pool user being given minimal rights (normally, to list and describe the tables, but without any actual access to them). This has some advantages:

the security is setup just once for the variety of applications that might access the database
each user can actually perform only the operations that he/she was allowed to, regardless of eventual bugs/security holes in the application level software
leverages the DBA expertise

GeoSolutions recently implemented the ability to use DBMS session startup and teardown scripts that can be used to alter the user accessing the database for the duration of the current request, turning back to the pool user when the request is complete.

These commands can be specified in the configuration User Interface while setting up the data store. For example, if we wanted to have each and every PostgreSQL session use the credentials of the current GeoServer user we'd use the following setup:

Different databases will of course use different commands, or custom, in house package calls, to setup the current session user. See the GeoServer documentation for more details on how this new functionality can be used.

We'd like to thank Astrium GEO-Information Services for sponsoring this improvement and sharing it with the GeoServer and GeoTools communities.

Application security is certainly one of the topics we like to deal with. There is of course a lot more to explore and improve, this topic is both rich and interesting. Want for example CAS or Shibboleth security in your GeoServer intallation? Maybe integration with Active Directory? Talk to us first!

The GeoSolutions team,

Sean Gillies: Geoprocessing for humans: date and time

sgillies@frii.com (Sean Gillies) — Mon, 30 Jan 2012 06:14:31 +0000

Fiona 0.7 roughly supports OGR date/time fields. Date, time, and datetime field values are turned into strings conforming to RFC 3339 "Date and Time on the Internet: Timestamps". Fiona is ignoring time zones in this version, but then OGR itself doesn't have much support for time zones, and neither do common vector data formats.

There's an example of adding a date type field to a shapefile in test_collection.py.

with collection("docs/data/test_uk.shp", "r") as source:
    schema = source.schema.copy()
    schema['geometry'] = 'Point'
    schema['properties']['date'] = 'date'
    with collection(
            "test_write_date.shp", "w", "ESRI Shapefile", schema
            ) as sink:
        for f in source.filter(bbox=(-5.0, 55.0, 0.0, 60.0)):
            f['geometry'] = {
                'type': 'Point',
                'coordinates': f['geometry']['coordinates'][0][0] }
            f['properties']['date'] = "2012-01-29"
            sink.write(f)

A look at the shapefile's feature table in QGIS shows that I'm getting writing of dates right.

Reading that shapefile back in Fiona confirms that dates are read properly.

>>> from fiona import collection
>>> c = collection("test_write_date.shp", "r")
>>> from pprint import pprint
>>> pprint(c.schema)
{'geometry': 'Point',
 'properties': {'AREA': 'float',
                'CAT': 'float',
                'CNTRY_NAME': 'str',
                'FIPS_CNTRY': 'str',
                'POP_CNTRY': 'float',
                'date': 'date'}}
>>> for f in c:
...     print f['properties']['date']
...
2012-01-29
2012-01-29
2012-01-29
2012-01-29
2012-01-29
2012-01-29
2012-01-29

Be careful with this feature. Unless your data is destined for a legacy system, I think you're better off keeping track of time as RFC 3339 strings in a text field. Among other advantages, you'd gain millisecond precision and precise expression of UTC time offset.

Nathan Woodrow: A new QGIS plugin: Python Script Runner

Mon, 30 Jan 2012 02:44:58 +0000

Gary Sherman has just published a new Python plugin for QGIS that I think people will find very handy, I know I will. The plugin allows you to run Python scripts inside QGIS for tasks that don’t really require, or warrant, a whole plugin.

Go check out Gray’s post about the new plugin at http://spatialgalaxy.net/2012/01/29/script-runner-a-plugin-to-run-python-scripts-in-qgis/

The new plugin can be installed via the Plugin Installer using the “runner” or “script”. The Plugin Installer is another one of my favorite plugins for QGIS, being able to push out a new plugin and know that everyone can get it is a good feeling :)

Filed under: Open Source, qgis Tagged: FOSSGIS, gis, Open Source, osgeo, plugin, python, qgis, Quantum GIS

Gary Sherman: Script Runner: A Plugin to Run Python Scripts in QGIS

Mon, 30 Jan 2012 02:24:34 +0000

Following up on my last post, Running Scripts in the Python Console, I created a plugin to simplify running scripts:

The Script Runner plugin allows you to add your scripts to a list so they are readily available. You can then run them to automate QGIS tasks and have full access to the PyQGIS API. In addition, you can view information about the classes, methods, and functions in your module as well as browse the source:

In order for your script to work with ScriptRunner it has to implement a single function as an entry point. Here is some additional information from the Help tab of the plugin:

Requirements

In order for Script Runner to execute your script you must define a run_script function that accepts a single argument. This is the standard entry point used by Script Runner. A reference to the qgis.utils.iface object will be passed to your run_script function. You don’t have to use the iface object in your script but your run_script function must accept it as an argument.

Here is an example of a simple run_script function:

    def run_script(iface):
        ldr = Loader(iface)
        ldr.load_shapefiles('/vmap0_shapefiles')

In this example, the run_script creates an instance (ldr) of a class named Loader that is defined in the same source file. It then calls a method in the Loader class named load_shapefiles to do something useful—in this case, load all the shapefiles in a specified directory.

Alternatively, you could choose not to use classes and just do everything within the run_script function, including having it call functions in the same script or others you might import. The important thing is to be sure you have defined a run_script function. If not, Script Runner won’t load your script.

Working with Scripts

To run a script, you must add it to Script Runner using the Add Script tool on the toolbar. This will add it to a list in the left panel. This list of scripts is persisted between uses of QGIS. You can remove a script using the Remove Script tool. This just removes it from the list; it does nothing to the script file on disk.

Once you have a script loaded, you can click the Script Info tool to populate the Info and Source tabs in the panel on the right. The Info tab contains the docstring from your module and then a list of the classes, methods, and functions found in the script. Having a proper docstring at the head of your script will help you determine the puprose of script.

You can view the source of the script on the Source tab. This allows you to quickly confirm that you are using the right script and it does what you think it will.

Installing the Plugin

To install the plugin:

Open the Python plugin installer: Plugins->Fetch Python Plugins
Check to see if you have the new Official repository in your list of plugins by clicking on Repositories tab. The URL is http://plugins.qgis.org/plugins/plugins.xml.
If you have it, skip to step 5. If the new repository isn’t in the list, add it by clicking the Add button. Give it a name and insert the URL http://plugins.qgis.org/plugins/plugins.xml
Click on the Plugins tab
Enter scriptrunner in the Filter box
Select the ScriptRunner plugin and click Install

ScriptRunner adds an entry to the Plugins menu as well as a tool on the Plugins toolbar: . Click it and you are off and running.

Sean Gillies: PyCon

sgillies@frii.com (Sean Gillies) — Sun, 29 Jan 2012 23:08:01 +0000

I've just finished booking flights and hotel for my first ever PyCon. I'll be in Santa Clara on March 8 and leaving on the 11th. There are 3 talks related to mapping and spatial analysis on the 10th and I hope to make at least one of them. I expect to see a few folks from Fort Collins and the Front Range there. Is there anyone else affiliated with NYU attending? Any programmers in the humanities? I'd like to meet you.

csgis: gvSIG CE Link Text to Layer

noreply@blogger.com (test) — Sat, 28 Jan 2012 10:02:52 +0000

A new functionality "Link Text to Layer" will be implemented in gvSIG CE that let you create links between text elements (map document) and layers (view document).
If you set a layer in the view as not visible, the text in the layout will disappear simultaneously.
To use this new link option follow these instructions:
1.- Add layers to one/more view/s
2.- Create a new map document and insert the view you want to present as a map
3.- Insert the text you would like to have in the map

4.- By Click activate the text object and open the context menu with a right mouse click. Select the option set visibility link, a window with selectable layers will be opened. Select the layer you want to link with your text map object

5.- The text now has an active link to the layer. If you set the layer as not visible in the view, the text will also disappear in the map. Selecting the option remove visibility link, the link between layer and text will be deleted.

Martin Davis: Let's do it again at FOSS4G-NA!

noreply@blogger.com (Dr JTS) — Sat, 28 Jan 2012 04:06:54 +0000

FOSS4G 2011 in Denver last September was such a good time, we're going to do it all over again at FOSS4G North America 2012!

It will be interesting to see who and how many attend. Some conference budgets might have been blown last year - but note that this event is cleverly timed to fall into a new fiscal! And being in D.C. there should be lots of suits and spooks in attendance.

I'm definitely looking forward to building on the momentum from the last conference, especially given my new gig with OpenGeo (ok, I'm definitely not booth-babe material - but being a booth-geek is probably more fun).

Tyler Mitchell: Ingres db access in QGIS via GDAL/OGR VRT

Sat, 28 Jan 2012 03:04:39 +0000

My title was already long enough, but I should have added the subtitle "...on Windows". Up until this week you had to be a Windows compiling guru and a GDAL/OGR master to get the driver for Ingres to build. With a wave of his hand, Frank fixed that this week and now I (a mere Windows padowan) was able to get it running. Here are a few of the things that transpired and some examples of the end result. Things are easier on Linux (what's new?), but I needed to crack the Windows nut for a few reasons since it wasn't quite as ready.

First off, if you are interested in hearing more about the Ingres geospatial capabilities, let me know or join our low volume, informal, list where I (am just starting to) post more info as it comes available or review our wiki (slowly getting updated). We are working, heads down, on getting the next Ingres db release out which will include geospatial capabilities in the core of the database (it's not an add-on). This release will be backed by Actian's subscription support services you can get 24/7 professional support for this open source product, with support spread around the world. Now onto the geek details...

Ingres Libraries & Database

Naturally you'll need Ingres db libraries to get started. We don't have a simple zip of files so I first pulled that together. You can likely download any of the Windows installer packs from the Ingres download pages: actian.com/downloads/ingres and it will include the library files you need. On my machine all the files I need were in two folders (lib and files) found in C:\Program Files (x86)\Ingres\IngresII\ingres\ with subfolders: lib - for libraries, and files - for headers/include.

If you also need the Ingres database too, grab a 10.1 (build 120+) installer to ensure it's capable. If that doesn't work then grab the windows installer from here that also included the geospatial capabilities but may be a little older. I haven't built Ingres from source on Windows yet, so won't attempt to walk you through that, but I'll get to that eventually.

Build GDAL/OGR

Grab the latest source for GDAL/OGR, the improvements were just committed this week. For those who may be new to GDAL/OGR - we are specifically interested in the OGR side of the equation as it manages the vector (not raster) data access we need.
Edit the nmake.opt file, specifically uncomment lines 356-360 and edit 356 to reflect the location of your Ingres libraries I mentioned above.
356 INGRES_DIR = C:\Users\tyler\src\ingres\ # files and lib folders are in here 357 INGRES_INC_DIR = $(INGRES_DIR)\files 358 INGRES_LIB = $(INGRES_DIR)\lib\iilibapi.lib \ 359 $(INGRES_DIR)\lib\iilibutil.lib \ 360 $(INGRES_DIR)\lib\libingres.lib
Then run, from the GDAL/OGR source folder:
nmake /f makefile.vc
It was that easy and I'm no pro on building on Visual Studio 2010 - having just downloaded the free express version last week.

(Note: I also built in GEOS support, it was just as easy to build from source in Windows, and all you need to do is edit nmake.opt as above but for GEOS after you have it built. You need this for our final step, if you want to hack up QGIS to use this new format from OGR.)

Check that it built in the support for Ingres by running, from the command line, some of the programs in the GDAL/OGR source\apps folder and adding the --formats option. For example:
apps\ogr2ogr --formats ... -> "MSSQLSpatial" (read/write) -> "Ingres" (read/write) -> "PCIDSK" (read/write) ...

Convert data to Ingres Geospatial

One of the reasons we really need this OGR support was for data loading and extracting. We are working on FME support but for those without FME, OGR and Geotools will remain critical!

Grab your favourite shapefiles and give ogr2ogr a try. The general syntax, to connect to a local Ingres database is like this:
ogr2ogr -f ingres @driver=ingres,dbname=[database name] [input.shp] -nln [new table name] #nln is optional e.g... ogr2ogr -f ingres @driver=ingres,dbname=canada roadlines.shp -nln roads
Depending on the projection/SRS of the data you may get notices complaining about not being able to INSERT into the spatial_ref_sys table. More on this at another time, but if you want to ignore it, feel free to add -skipfailures and/or -overlap - if you want to run it again easily.

The Ingres database access application is called 'sql' - when you run this from a command line you get an interactive session. Type 'help \g' (\g being like the ; on other databases) and it will list the tables that are in your database. You can also run:
ogrinfo @driver=ingres,dbname=[database name] - to see if the table was created.

Viewing QGIS

There is no QGIS specific database access provider setup for Ingres.. yet. (Want to help with it? Let me know!) So the approach I thought I try, was to use the OGR Virtual Format. For this you simply create an XML file that includes the connection information you used above. This virtual format is way more powerful than that but this will get you started:

<OGRVRTDataSource>
   <OGRVRTLayer name="road">
    <SrcDataSource>@driver=ingres,dbname=canada</SrcDataSource>
    <SrcLayer>road</SrcLayer>
      <GeometryType>wkbLinestring</GeometryType>
      <LayerSRS>EPSG:4326</LayerSRS>
      <GeometryField>shape</GeometryField>
    </OGRVRTLayer>
</OGRVRTDataSource>

Before you can use this in QGIS, consider that the GDAL/OGR that is distributed with it does not include Ingres support that we built earlier. Let the hacking begin, unless you want to build QGIS from scratch on Windows too :) I was using OSGeo4W - a great distribution for Windows with an easy to use installer for getting QGIS, GRASS and more up and running quickly. I copied these files from GEOS and GDAL into the OSGeo4W bin folder, after backing them up first of course :). Yes, this is a total hack but it saved me from rebuilding QGIS - ideally this won't be necessary in the future if we can get Ingres support built into the base distributions of GDAL/OGR.

cd C:\OSGeo4W\bin
rename gdal18.dll gdal18.dll.orig
rename geos_c.dll geos_c.dll.orig
copy C:\Users\tyler\src\gdal-svn\gdal19.dll gdal18.dll
copy C:\Users\tyler\src\geos-3.3.2\src\geos_c.dll

Now, start up QGIS, select Layer -> Add Vector Layer. Choose Browse for a dataset. Change the drop down type filter box (bottom right) to VRT - Virtual Datasource [OGR], find your VRT file and select Open. Give it some time, I found it slow, at least on this low end laptop I was using. I didn't get it to display attribute tables, likely due to my ignorance of the VRT format options and querying is slow.

Summary

So OGR is working well with Ingres geospatial types and I'm really glad we've got that ready to go on both Linux and Windows (anyone want to try Mac?). We have a queue of fixes, improvements and new features to add to the Ingres database over the upcoming months. We are also focusing on performance (any R-Tree gurus around interested in digging into the Ingres indexing code with us? :) ). This initial development and testing has us off to a good start and I hope you'll be interested in following along as we continue toward our next release. If you are interested in learning more or share thoughts I invite you to drop me a note at tyler.mitchell at actian !dot! com. Or follow me on Twitter. You can also read about my open source geo book publishing endeavours at http://locatepress.com.

Sandro Santilli: A walk on the wild side

Sat, 28 Jan 2012 00:03:20 +0000

How topology starts making sense in PostGIS 2.0.0

OpenGeo Blog: Getting Curvey

Fri, 27 Jan 2012 20:39:16 +0000

PostGIS has supported curved geometry types — CIRCULARSTRING, COMPOUNDCURVE< CURVEPOLYGON — since version 1.4, but the number of functions that directly calculate against the curved features has remained pretty small. You can generate a bounding box, or calculate a length, but that’s about it.

A COMPOUNDCURVE made up of a line string, a circular arc, and another line string.

In order to do more complex calculations like area calculation or intersections, you have to first convert the curved object into a linearized approximation, using the ST_CurveToLine function. This is fine for functions that return numbers (like ST_Area) or booleans (like ST_Intersects), but what about functions that return derived geometries?

Linearized version of the compound curve. The arc has been replaced by a regular collection of lines.

For derived geometries, the result will be linearized like the inputs. But portions of the geometry will be linearized versions of the original curves: wouldn’t it be nice to have those curves back for storage?

Yes, it would which is why ST_LineToCurve exists. The line to curve logic works on the premise that a linearized version of a curve will have a certain amount of regularity in it.

The version of the code from PostGIS 1.4 and 1.5 works by looking at the angles between successive segments. Segments that share an angle of deflection with neighbours are probably components of a circular arc. This worked OK, but the code involved a fair amount of trigonometry.

By looking at angles between edges, you can find edges that are former components of an arc.

A simpler approach used for 2.0 turned out to be looking at the circle the arc is inscribed on. Any circular arc in PostGIS is defined by a start point, mid point and end point. Between them, they imply a circle, and the center of the circle can be calculated. Any successive point which is the same distance from that center point as the arc points can be considered part of the arc.

By using the circle as a basis for comparison, each successive point needs a simple distance check, instead of a trig check.

The new code is a lot simpler, and can deal with derived segments of more variable length that the old code.

The simplest way to prove that it works is to wrap a curved geometry in multiple nests of ST_LineToCurve and ST_CurveToLine, pushing the geometry back and forth between representations. While the functions are not perfect inverses (the segmentization routine doesn’t necessarily include the middle control points of the input arcs) you can see that the space bounded by the geometries does not change.

Happy curving!

Sean Gillies: Geoprocessing for humans: a pip requirements file

sgillies@frii.com (Sean Gillies) — Fri, 27 Jan 2012 17:52:57 +0000

In the geospatial software I'm writing and using these days, concerns are well separated. Fiona reads and writes features. Only. Shapely provides computational geometry algorithms. Only. Pyproj (not my work, but a favorite package) transforms coordinates between spatial reference systems. Only. The separation of concerns helps keep interactions between them predictable and as a user you pay only for what you eat.

A programmer-analyst's daily work has all the above concerns (and more, probably). A pip requirements file makes installing all three packages as easy as installing a single package like osgeo.ogr. I've uploaded one to GitHub: https://gist.github.com/1689767. This Gist includes an example of using Fiona, pyproj and Shapely together. Fetching them all, assuming you've got pip and the GDAL/OGR libs and headers already on your system, is just:

$ pip install -r https://raw.github.com/gist/1689767/mersh.txt

Gary Sherman: QGIS: Running Scripts in the Python Console

Fri, 27 Jan 2012 17:10:51 +0000

The QGIS Python console is great for doing one-off tasks or experimenting with the API. Sometimes you might want to automate a task using a script, and do it without writing a full blown plugin. Currently QGIS does not have a way to load an arbitrary Python script and run it¹. Until it does, this post illustrates a way you can create a script and run it from the console.

There are a couple of requirements to run a script in the console:

The script must be in your PYTHONPATH
Just like a QGIS plugin, the script needs a reference to qgis.utils.iface

Setting up the Environment

By default, the Python path includes the .qgis/python directory. The location depends on your platform:

Windows: in your home directory under .qgis\python. For example, C:\Documents and Settings\gsherman\.qgis\python
Linux and OS X: $HOME/.qgis/python

To see what is in your PYTHONPATH you can do the following in QGIS Python console:

import sys
sys.path

While you could use the .qgis\python directory for your custom scripts, a better way is to create a directory specifically for that purpose and add that directory to the PYTHONPATH environment variable. On Windows you can do this using the Environment Variables page in your system properties:

On Linux or OS X, you can add it to your .bash_profile, .profile, or other login script in your home directory:

export PYTHONPATH=$PYTHONPATH:/home/gsherman/qgis_scripts

Writing the Script

With the environment set, we can create scripts to automate QGIS tasks and run them from the console. For this example, we will use a simple script to load all shapefiles in a specified directory. There are a couple of ways to do this:

Write a simple script with a function that accepts qgis.utils.iface as an argument, along with a path to the shapefiles
Create a Python class that uses an __init__ method to store a reference to the iface object and then add methods to do the work

We will use the latter approach because it is more flexible and allows us to initialize once and then call methods without having to pass the iface object each time.

The script looks like this:

#!/usr/bin/env Python
"""Load all shapefiles in a given directory.
  This script (loader.py) runs from the QGIS Python console.
  From the console, use:
    from loader import Loader
    ldr = Loader(qgis.utils.iface)
    ldr.load_shapefiles('/my/path/to/shapefile/directory')
 
  """
from glob import glob
from os import path
 
class Loader:
    def __init__(self, iface):
        """Initialize using the qgis.utils.iface 
        object passed from the console.
 
        """
        self.iface = iface
 
    def load_shapefiles(self, shp_path):
        """Load all shapefiles found in shp_path"""
        print "Loading shapes from %s" % path.join(shp_path, "*.shp")
        shps = glob(path.join(shp_path, "*.shp"))
        for shp in shps:
            (shpdir, shpfile) = path.split(shp)
            self.iface.addVectorLayer(shp, shpfile, 'ogr' )

Running the Script

To open the console use the Plugins->Python Console menu item.

The comment at the head of the script explains how to use it.

First we import the Loader class from the script file (named loader.py). This script resides in the qgis_scripts directory that is our PYTHONPATH.

from loader import Loader

We then create an instance of Loader, passing it the reference to the iface object:

ldr = Loader(qgis.utils.iface)

This creates the Loader object and calls the __init__ method to initialize things.

Once we have an instance of Loader we can load all the shapefiles in a directory by calling the load_shapefiles method, passing it the full path to the directory containing the shapefiles:

ldr.load_shapefiles('/home/gsherman/qgis_sample_data/vmap0_shapefiles')

The load_shapefiles method uses the path to get a list of all the shapefiles and then adds them to QGIS using addVectorLayer.

Here is the result, rendered in the random colors and order that the shapefiles were loaded:

Some Notes

When testing a script in the console you may need to reload it as you make changes. This can be done using reload and the name of the module. In our example, reload(loader) does the trick.
You can add more methods to your class to do additional tasks
You can create a “driver” script that accepts the iface object and then initializes additional classes to do more complex tasks

1. I have plans on the drawing board to implement this feature.

Free and Open Source GIS Ramblings: Looking for Roundabouts in OSM

Fri, 27 Jan 2012 11:17:11 +0000

Roundabouts are handled interestingly in OSM: They can be both nodes or ways and represented as points, lines or polygons.

And this is how they can be downloaded for a specific area:

> wget http://open.mapquestapi.com/xapi/api/0.6/node[highway=mini_roundabout][bbox=15.86,47.95,16.88,48.70] > wget http://open.mapquestapi.com/xapi/api/0.6/way[junction=roundabout][bbox=15.86,47.95,16.88,48.70]

Note: Not all XAPI servers are available all of the time. Check this site if the server is down: OSM Wiki – Xapi.

Cameron Shorter: Presenting at GeoNext conference

noreply@blogger.com (Cameron Shorter) — Fri, 27 Jan 2012 01:46:25 +0000

I'm speaking at the GeoNext conference, and will be answering audience questions on the topic of:

"Where to start with Geospatial Open Source Software, and how to build a business around Open Source products".

Speakers at the GeoNext conference are covering topics around emerging geospatial business trends, which are being driven by such things as mobile phones, commoditisation of data, and web 2.0 principles such as crowd sourcing. It is running in Sydney, Australia on 29 February 2012. More details here: http://geonext.com.au/
If you will be coming, then let me know and come and say hello.

Slashgeo (FOSS articles): OpenGeo Announces Gold Level Sponsorship for 2012 FOSS4G-NA

Thu, 26 Jan 2012 21:01:51 +0000

OpenGeo Announces Gold Level Sponsorship for 2012 FOSS4G-NA

FOSS4G North America Regional Conference to be Held in Washington, D.C.

New York, NY, January 26, 2011 — OpenGeo, the organization behind the OpenGeo Suite has announced their sponsorship of the 2012 FOSS4G-NA conference. The Free and Open Source Software for Geospatial - North America (FOSS4G-NA) conference will be hosted by OSGeo North America from April 10th to 12th, 2012 at the Walter E. Washington Convention Center in Washington, D.C. Confirmed keynote speakers include Michael Byrne, CIO of the Federal Communications Commission (FCC).

OSGeo North America is the newly-formed North America chapter of OSGeo, an international not-for-profit whose mission is to support and promote the collaborative development of open geospatial technologies and data. OSGeo North America has scheduled this regional follow-up to focus on the North American open source geospatial community. Just as they did at the 2011 FOSS4G global conference in Denver, OpenGeo is once again committed to a gold level sponsorship, In addition, this year members of OpenGeo are also volunteering on the conference organizing committee.

Eddie Pickle, OpenGeo COO said "Supporting FOSS4G and OSGeo is a top priority for OpenGeo. FOSS4G is always a key forum for meeting with our friends, clients, and partners as well as for exchanging knowledge to improve open source geospatial software. A regional event in Washington, D.C. will allow us us to focus on the evolving landscape of open source geospatial in North America. We’re especially interested to see how government agencies have been adopting open source technology to address their needs." He continued "We’re also happy to announce that our own Paul Ramsey has volunteered to be the FOSS4G- NA 2012 conference chair; we know the conference will be a success with Paul at the helm."

About FOSS4G-NA 2012

FOSS4G is an annual global conference organized by OSGeo that focuses on bringing together individuals and organizations working with free and open source geospatial software; FOSS4G-NA is a regional event for North America and is being organized by the North American Regional chapter of the Open Source Geospatial Foundation (OSGeo), with additional support from members of a volunteer program and conference committee and the conference sponsors

About OpenGeo

OpenGeo is a social enterprise working to build the best web-based geospatial technology. The company brings the best practices of open source software to geospatial organizations around the world by providing enterprises with supported, tested, and integrated open source solutions to build the Geospatial Web. OpenGeo also supports open source communities by employing key developers of PostGIS, GeoServer, and OpenLayers. Since 2002, the company has provided successful consulting services and products to clients like the World Bank, Google, Ordnance Survey Great Britain, Portland TriMet, MassGIS, Landgate, and the Federal Communications Commission. OpenGeo is the geospatial division of OpenPlans, a New York-based 501(c)(3) non-profit that informs and engages communities through journalism and open source software. All of OpenGeo's revenue has been and will continue to be re-invested into innovative and useful software in support of the OpenPlans mission.

Daniel Morissette: Intellectual Property vs Copyright

noreply@blogger.com (Daniel Morissette) — Thu, 26 Jan 2012 18:22:52 +0000

In the past I have often used the terms Intellectual Property and Copyright to mean essentially the same thing, without realizing that this was incorrect. Maybe that was because English is not my native language, but probably not since I have actually heard several others making the same mistake as well.

This morning in a discussion on this topic on the OSGeo Incubator mailing list, Frank Warmerdam explained the difference between the two terms and now I better understand why the terms Intellectual Property and Copyright should not be confused, especially in the context of Free and Open Source Software (FOSS).

I thought I'd share a copy of Frank's great explanation here in case it helps others better understand the distinction:

Daniel,

I believe the rationale behind avoiding the term Intellectual Property
has two parts.

First, it attempts to conflate a variety of very different legal mechanisms.
Primarily copyright, patents and trademarks. Giving them all one name makes
it harder to separate out things we might agree with (copyright) from things
we might not (ie. Patents).

Second, it expresses these legal mechanisms in a manner that implies that
they are some sort of fundamental or manifest right rather than limited
government granted monopolies intended to serve specific needs of society

[...]

You can read the full email and the rest of the thread here.

Simone Giannecchini: Improving GeoServer SQL Server support

noreply@blogger.com (Andrea Aime) — Thu, 26 Jan 2012 10:42:26 +0000

Dear All,

in recent times we were hired to improve GeoServer SQL Server support story.

The SQL Server store was created and maintained during spare time by Justin DeOliveira, however due to lack of production usage, and work time to pour on it, it failed to reach to the same level of robustness and speed as the best supported stores, such as Oracle and PostGIS.

Our work this week tried to close this gap with a number of little and big improvements that make the code run faster and in a more reliable way:

add support for connection validation (very important for SQL Azure, which is very keen on closing pooled connections in your face)
use binary encoding, instead of text, to transfer geometries from the database
support for data paging at the database level
make sure the rich database test suite we have in GeoTools is fully implented for SQL server, ensuring good support for use cases such as dynamic SQL views, proper date/time encoding in filters, and the like, both on the development series and on the stable series

Our develoment focused on testing the code against both SQL Server 2008 and SQL Azure. SQL Azure is the SQL database one can use in the Microsoft Azure cloud system: while it does look a lot like SQL Server 2008, it does not quite behave the same way in all cases, and requires a specific JDBC driver to work properly.

There are still some improvements missing on the table, such as geography columns support, but we're sure you'll be able to get more out of a production usage of GeoServer and SQL Server now.

Interested in sponsoring further improvements? Looking for professional support service that deliver for your group? Let us know!

The GeoSolutions team,

Micha Silver: Spatialite and Excel on talking terms

Wed, 25 Jan 2012 19:53:59 +0000

The recent stable version of Spatialite, 3.0, supports linking to and importing Excel spreadsheet tables. Read on to see how it’s done.

The developers of spatialite have added a driver for *.xls files (thru the FreeXL library ). You can either link to, or import a single sheet from an Excel file provided that:

the file is Excel 2003 format (not the newer xml format)
the table is “cleanly” formated – only data in rows, no empty rows, etc.
the first row contains either column headers, or straight-away the first data entry

However the columns of data are imported into spatialite without any data type. If you want to specify the data type for each column, my procedure is:

link to the external table (create a virtualXL table)
create your own, well defined table
use the SQL construct “INSERT INTO … SELECT FROM…” in order to copy all data from the linked table into your structured table.
then run the spatial funtions AddGeometryColumn() and MakePoint() in order to convert the table to a spatial layer

These few steps might seems a bit complex just to get a table of data into spatialite, but this method insures that data will be structured exactly as you want.

If you’re working with spatialite from the command line, here’s the command syntax for loading an excel sheet:

.loadxl <args> Loads a XL spreadsheet (.xls) into a SpatiaLite table arg_list: xl_path table_name [worksheet_index [first_line_titles{0/1}]]

Note that the worksheet index begins with 0. So if you have more than one sheet in your Excel file, be sure to set the correct index for the worksheet containing the table. The last parameter indicates (by values 0 or 1) whether the first row holds column headers. So for example you could import the first sheet of an excel worksheet called ‘host_trees.xls’, which contains column headers in the first row, with the following command:
spatialite>.loadxl 'host_trees.xls' host_trees 0 1 XL loaded

3770 inserted rows
spatialite>

We’ll follow the full procedure to smoothly import a spreadsheet of longitude,latitude data and create a spatial layer with screen shots from the spatialite_gui. Suppose we begin with a table that looks like this:

Excel table of data with Longitude/Latitude loctaions

First import the table using the VirtualXL button. This creates a link in the spatialite db to the sheet from Excel.

Importing an Excel table as VirtualXL

In the next image note that the linked data table has no types for the columns. So we’ll create our premanent table (named here ‘MyHostTrees’)within spatialite, specifying the correct data types, then we will transfer the date over from the virtual table to the permanent one. Follow the steps…

Crete a new, permanent table with correct data types

Now we transfer the data from the virtual table to the permanent table using the SQL construct: “INSERT (…) INTO … SELECT … FROM …”. Here’s how it looks:

Copy data from virtual table to permanent table

We continue by making this new table a spatial table with the AddGeometryColumn() function, then we populate this Geometry column using the MakePoint() function.

Using the AddGeometryColumn function

Populating the Geometry column

And here’s the result:

Spatial table containing data with Geometry column

Gary Sherman: Using the QGIS Raster Calculator

Wed, 25 Jan 2012 18:12:44 +0000

The raster calculator allows you to perform mathematical operations on each cell in a raster. This can be useful for converting and manipulating your rasters. Operators include:

Mathematical (+, -, *, /)
Trigonometric (sin, cos, tan, asin, acos, atan)
Comparison (<, >, =, <=, >=)
Logical (AND, OR)

To perform operations on a raster or rasters, they must be loaded in QGIS. The raster calculator is accessed from the Raster menu and brings up the dialog:

Let’s look a few examples.

Simple Mathematical Calculation

Doing a simple calculation is easy. In this example we have a Digital Elevation Model (ancc6) loaded in QGIS. The DEM contains elevations for a 1:63,360 quadrangle in Alaska. The coordinate system is geographic and the elevation value in each cell is in meters. If we wanted to create a raster with elevation in feet, we can use these steps to create the expression:

Bring up the raster calculator
Double click on ancc6@1 in the raster bands list to add it to the expression
Double click the multiplication operator (*)
In the expression box, type in the conversion factor for meters to feet: 3.28

This gives us the following expression:

ancc6@1 * 3.28

To complete the process, we specify a name for the output raster and the format we want to use. When you click OK, the operation will be performed and the new raster created, giving us a GeoTIFF with cell values in feet. If you leave the Add result to project box checked the output raster will be added to QGIS once the calculations are done.

If you only want to operate on a portion of a raster, you can use the extent setting to limit the area included in the calculation.

Using a Mask

Sometimes you might want to mask out part of a raster. An example might be one where you have elevations ranging from below sea level to mountain tops. If you are only interested in elevations above sea level, you can use the raster calculator to create a mask and apply it to your raster all in one step.

The expression looks like this:

(my_raster@1 >= 0) * my_raster@1

The first part of the expression in parentheses effectively says: for every cell greater than or equal to zero, set its value to 1, otherwise set it to 0. This creates the mask on the fly.

In the second part of the expression, we multiply our raster (my_raster@1) by the mask values. This sets every cell with an elevation less than zero to zero. When you click OK, the calculator will create a new raster with the mask applied.

Simulating a Rise in Seal Level

Using the raster calculator and a mask we can visually simulate a rise in sea level. To do this we simply create the mask and overlay it on the DEM or perhaps a DRG (topographic) raster.

The expression to raise sea level by 100 meters is:

ancc6@1 > 100

The output raster contains cells with either a 0 (black) or 1 (while) value:

The black areas represent everything below an elevation of 100 meters, effectively illustrating a sea level rise. When we combine this with a suitable background we can demonstrate the results:

We added the DRG for the quadrangle and overlaid it with the mask layer. Setting the transparency to 70% allows the DRG to be seen, illustrating the effect of raising sea level.

The raster calculator is a powerful tool. Check it out and see how you might use it in your analysis and map making.

Sean Gillies: Notes on learning Clojure

sgillies@frii.com (Sean Gillies) — Wed, 25 Jan 2012 17:13:08 +0000

I'm learning Clojure and having fun with it. I never learned a Lisp in school like many programmers my age did. The one variant I did try, about 15 years ago, was Scheme. I did a little Gimp scripting with it but nothing else. I think I had to mature a bit before I could appreciate the Lisp style for what it is.

For a language that's designed to be more simple than easy, it's surprisingly easy to use Java classes in Clojure. This is the first code I've written using JTS classes in a while.

user=> (.buffer
  (.read (com.vividsolutions.jts.io.WKTReader.) "POINT (0 0)")
  1.0)
#<Polygon POLYGON ((1 0, 0.9807852804032304 -0.1950903220161282, ...))>

I assumed I'd have to write something like a Python C extension module to do this and am thrilled to be wrong.

Slashgeo (FOSS articles): Marble 1.3.0 and "Marble Touch" Released

Wed, 25 Jan 2012 14:15:43 +0000

Marble 1.3 has been released with lots of new gems: Marble — the virtual globe and world atlas — now integrates with KDE Plasma. By allowing for coordinate and bookmark searches, Marble can be opened directly from the Plasma search bar.

The new Elevation Profile shows the incline of routes, which can be edited interactively.

Stargazers can view and track Earth satellites thanks to Marble participation in the European Space Agency (ESA) Summer of Code in Space.

During Google Summer of Code, Marble gained initial support for display of .osm (OpenStreetMap) files in vector format.

Owners of the Nokia N9/N950 are the first to receive the new mobile application Marble Touch.

Further details can be found in the feature guide.

Matt Sheehan: Flexible Mobile GIS Frameworks

Wed, 25 Jan 2012 13:53:15 +0000

We have spoken many times on this blog about our release of GeoMobile for ArcGIS. The link below will take you to a more detailed discussion:

http://www.webmapsolutions.com/free-mobile-arcgis-viewer-upgraded

Our logic for the release was:

To demonstrate a custom ArcGIS mobile application Build a cross platform mobile GIS app or one code base which runs on multiple platforms; iOS, [read full article]

Gavin Fleming: Confessions of an ex-Windows user

Wed, 25 Jan 2012 09:18:43 +0000

Education is undoubtedly the largest propaganda weapon in this consumerist-driven society. Having just completed matric, I realize that the first eighteen years of my life has been a period of unmitigated Windows brainwashing. It is a travesty to think how the capitalist greed of proprietary software has permeated my life for so long.

I recently began working at AfriSpatial with the intention of keeping myself busy during the holiday and earn some pocket money in the process. I was required to work in Linux which was a somewhat foreign OS to me and, afraid it would mysteriously hurt my fragile Windows PC, I installed Xubuntu OSGeo Live in a Virtual Box. At this stage life was treating me well…

One day, Windows decided to do an update which broke the harmony of my Virtual Machine by somehow preventing connection to the Internet. I wasted precious hours troubleshooting every conceivable error but this was to no avail. I had two choices: either forget about Linux and revert to the primitive ways of life before Linux or take a bold new step into a brighter future. So I actually had no choice and no more patience. I had to install Linux as a dual-boot. There was no other way.

This seemingly inconsequential event instigated a change; a purgation of conscience whose effects altered the kernel of my value system. I guess in hindsight this transmogrification was inevitable for an aspiring programmer.

Having joined the ranks of the converted Linux users, life has become so much brighter, so much more fulfilling, so much more. Gone are the days of tasteless architecture and graphics. The experience has been liberating. I blame schools for polluting their computer labs with expensive proprietary software when there are open source equivalents for just about everything (and often these ‘alternatives’ are better). Open source is undoubtedly the way forward. Anything Windows can do, Linux can do better. I am not trying to be antagonistic, just honest.

These are the confessions of an ex-Windows user.

Confessions of an ex-Windows user is a post from: AfriSpatial