OSGeo Planet

Paulo van Breugel: K-fold cross validation in GRASS GIS

OSGeo Planet - Thu, 2017-07-27 16:28
A common technique to estimate the accuracy of a predictive model is k-fold cross-validation. In k-fold cross-validation, the original sample is randomly partitioned into a number of sub-samples with an approximately equal number of records. Of these sub-samples, a single sub-sample is retained as the validation data for testing the model, and the remaining sub-samples …

Continue reading K-fold cross validation in GRASS GIS

Categories: OSGeo Planet

GIScussions: FOSS4G, from Nottingham to Uganda to Boston

OSGeo Planet - Thu, 2017-07-27 13:58

FOSS4G 2013 Logo

I have recently been chatting by mail with Bernard Muhwezi who is the Manager of Geo-Information Services at the Uganda Bureau of Statistics. Bernard is attending FOSS4G in Boston this year, he told me about what had happened in his country since he returned from FOSS4G 2013 in Nottingham, (Bernard authorised me to share this mail)

I attended FOSS4G Nottingham, and collected materials and CDs and trained in QGIS, when I came back I trained 54 mapping staff in-house, and we mapped the whole country and digitized the geography to the lowest level of census 2014 enumeration areas with QGIS and have since encouraged my agency to adopt FOSS (see attached). We have had all our staff and the students that have their internship at my division train and utilize FOSS since then.

We are very seriously interested, and even-if we are unable to obtain the funds to participate in such Conferences, tell your colleagues out there that they have been of great contribution to our work here in Uganda at large. While we never easily managed to source and maintain vendor offshelf GIS softwares like ESRI and others, QGIS, SAGA, GRASS, etc have made our work visible and we shall now continue to encourage ourselves forward.

What a great example of how attendance at FOSS4G and the enthusiasm of one user led to  the adoption of FOSS at the UBS. This is why all of us who volunteer, who write the software and the docs and work on the outreach programmes and running the events do it. And FOSS4G is the culmination of our year.

I’m looking forward to meeting Bernard and over a thousand other open source geo developers, advocates and users at FOSS4G in Boston in a couple of weeks.

If you would like to help someone like Bernard attend the next FOSS4G then you could do worse than make a donation to the FOSS4G Travel Grant Programme

Categories: OSGeo Planet

gvSIG Team: Towards gvSIG 2.4: SQL Server

OSGeo Planet - Thu, 2017-07-27 09:15

As we told in a previous post about SpatiaLite, in the next gvSIG Desktop version we will have a great number of improvements related to databases. We can find SQL Server support among them.

SQL Server is a relational database management system, developed by Microsoft. Probably Oracle and SQL Server are the most used proprietary databases.

At this way we continue increasing the data source support in gvSIG Desktop.

Filed under: development, english, gvSIG Desktop, testing Tagged: database, geodb, gvSIG-2.4, SQL Server
Categories: OSGeo Planet

gvSIG Team: Camino a gvSIG 2.4: SQL Server

OSGeo Planet - Thu, 2017-07-27 07:49

Como comentábamos en otro post sobre SpatiaLite, en la próxima versión de gvSIG Desktop vamos a tener un buen número de mejoras relacionadas con bases de datos. Entre ellas podremos encontrar el soporte a SQL Server.

SQL Server es un sistema de manejo de bases de datos del modelo relacional, desarrollado por la empresa Microsoft. Probablemente, junto a Oracle, sea una de las bases de datos privativas más utilizadas.

De este modo continuamos ampliando el soporte a fuentes de información en gvSIG Desktop.

Filed under: gvSIG Desktop, spanish Tagged: bases de datos, geodb, gvSIG-2.4, SQL Server
Categories: OSGeo Planet

gvSIG Team: Towards gvSIG 2.4: SpatiaLite

OSGeo Planet - Thu, 2017-07-27 06:33

At the next version of gvSIG Desktop we will find a series of improvements related to databases. One of them is the SpatiaLite support.

SpatiaLite is an SQLite database engine where spatial functions have been added. SQLite is a simple, solid, easy-to-use and swift Database Manage System (DBMS).

One of the main advantages is that each SQLite database is a file that can be copied, zipped and interchanged in an easy way.

In addition, Geopaparazzi (and the next gvSIG Mobile) works with this database, so this improvement will allow to interchange work data from our Desktop and Mobile GIS in an easy way.

Here you have a short video where we can see how a shapefile can be exported to SpatiaLite:

Filed under: development, english, gvSIG Desktop Tagged: Database Manage System, gvSIG-2.4, SpatiaLite, SQLite
Categories: OSGeo Planet

Jackie Ng: Announcing: mapguide-react-layout 0.9.5

OSGeo Planet - Wed, 2017-07-26 18:08
This was originally going to be versioned 0.9.2, but the volume of changes was too big to be a bugfix-level single patch version bump, but at the same time, it was also not enough to warrant a minor version bump, so I decided to go half way with 0.9.5.

Here's what's new in this release.

Toggle-able Layer Transparency

The viewer options UI is now fleshed out to allow you to toggle transparency of:

  • The MapGuide map (and any tiled layer groups)
  • The MapGuide selection overlay
  • External Base Layers
To illustrate this, here's a self-explanatory GIF

This allows one to easily compare the MapGuide map against its base layer backdrops without requiring actual visibility toggling.
And yes, this works even on IE (11, the only version I care to support)
Sprite Icon Support
This release now supports the standard Fusion icon sprite. This will no longer load the individual icons for commands and widgets if it is clear they are referencing the standard icon sprite.

Targeted Command Support
If a command or widget requires execution in a New Window or a specific frame, the viewer will now support it. Note that if a command or widget is set to execute in a New Window, we won't actually spawn a new physical browser window, we'll run it in an iframe inside a BlueprintJS dialog component instead.
Other Changes/Fixes
  • Added support for extension properties for Buffer, FeatureInfo, Query, Search, SelectWithin, Theme.
  • Fixed Fusion MapMessage bar emulation
  • Fixed tooltip queries not being sent with pixel-buffered polygon geometries
  • Fixed zoom requests not snapping the scale to the closest finite list if viewing a tiled map
  • Legend now properly renders layers with multiple geometry styles
  • Fix excessive BlueprintJS toaster components being created and not cleaned up
  • Fix flyout menus requiring double-click to re-open (after clicking a menu item inside the first time)

Project Home PageDownloadmapguide-react-layout on npm
Categories: OSGeo Planet

gvSIG Team: Camino a gvSIG 2.4: SpatiaLite

OSGeo Planet - Wed, 2017-07-26 11:35

En la próxima versión de gvSIG Desktop vamos a encontrar un buen número de mejoras relacionadas con bases de datos. Una de ellas es el soporte de SpatiaLite.

SpatiaLite es un motor de base de datos SQLite al que se le han agregado funciones espaciales. SQLite es un Sistema Gestor de Bases de Datos (SGBD, DBMS por sus siglas en inglés) que es simple, robusto, fácil de usar y muy ligero.

Una de las ventajas que presenta es que cada base de datos SQLite es simplemente un archivo que se puede copiar, comprimir e intercambiar fácilmente.

Por otro lado, Geopaparazzi (y el próximo gvSIG Mobile) trabajan con esta base de datos, por lo que esta mejora va a permitir intercambiar de forma sencilla los datos de trabajo entre nuestro SIG de escritorio y móvil.

Os dejo con un pequeño vídeo en que vemos como se exporta un shapefile a SpatiaLite:

Filed under: Geopaparazzi, gvSIG Desktop, gvSIG Mobile, spanish Tagged: Base de datos espacial, geodb, SpatiaLite, SQLite
Categories: OSGeo Planet

gvSIG Team: Towards gvSIG 2.4: Icon theme configuration

OSGeo Planet - Wed, 2017-07-26 11:05

This utility, called “Icon theme configurator”, will allow the user to create its own icon sets, in order to customize the appearance of his own gvSIG Desktop, (for more information, check out the previous post about the new set of icons available in gvSIG 2.4).

These new tools will also allow the user to create a package with the icon theme created, so it is possible to share it and install it through the “Add-on Manager”.

What is an icon set?

gvSIG Desktop has internally an icon set which includes all the images that are used in the program interface such as the menu and button icons, cursors, document icons, TOC layer icons…

In addition to the default icon set that we have been using in gvSIG since some previous versions already, gvSIG is able to load other kind of icon sets. In this post we will show you how to do it.

The “Icon theme configurator” plugin can be installed from the ‘Add-on Manager’, as shown in the following video:

This functionality will allow the user:

  • To view the variety of icons that has already installed.
  • To apply as default a set of icons to the gvSIG Desktop interface.
  • To create a new set of icons.
  • To create packages with sets of icons.

How to work with the ‘Icon theme configurator’?

When installed, the ‘Icon theme configurator’ tool cannot be reachable through the toolbar of gvSIG or through the menus. The start must be done through the “script launcher” or directly from the “script editor”.
In this example we will open the “Icon theme configurator” through the “script launcher”:

Then, we select the “iconThemeConfigurator” script by clicking on it twice, as it is shown in the image:

And the following window will pop up:

Firstly, in the “View” tab, it will appear the list of icon sets that we have already installed. By selecting the icons it is possible to preview them, to see their name and the group they belong to.

Secondly, in the “Select” tab, we will see the full list of icon sets installed in gvSIG. We must select one set as default. This step can also be done from the “Preferences” side of the application, in the section “General / Icon Set”.

Then, in the “Create” tab we can export a folder located in “gvSIG / icon-theme” the internal gvSIG Desktop icon set. We must indicate a code, name, author and description. The most relevant fields are the code (which will be the name of the folder that will be created in the route gvSIG / icon-theme”) and name”. It is recommended that the code does not contain spaces or special characters (letters, numbers and hyphens only).

Once the theme is created, and the name and location of the file appear in subfolders, then it is possible to replace the “internal” icons with the new ones we have previously created, keeping the name and location.

In the following video the whole procedure is shown step by step:

When the replacing of the original icons with the new ones is done, the next step would be to create a package. The user will be able to share and install the Package from the “Add-on Manager”. This task can be performed on the “Package” tab:

First we will have to select the folder of our game of icons. Click “Next” and fill in the metadata of the package. It is important to fill in the fields that appear in red, as this information is the one that will be displayed in the “Add-on Manager”, when a user is going to install the plugin containing an icon set.

Press “Next” again and it will show the route and name of the package that will be created; By default it is saved in the “Install” folder located in the following route “gvSIG-desktop / gvSIG-desktop-2.4.0”. Then the user will have the package ready to work with.

Finally, in this video it is shown the process of creating a package from an icon set:

Following this procedure a game icons will be created in a format of 16 × 16 and 22 × 22 pixels, as presented in an earlier post of the gvSIG blog.

To sum up, in this article of the blog we have shown you the very simple steps needed to change an icon set in gvSIG from version 2.4 – on. We only have to redesign the game of icons that we want to apply to our favorite GIS.

Filed under: english, gvSIG Desktop Tagged: gvSIG-2.4, icon configuration, icon package, icon sets, icon theme configuration
Categories: OSGeo Planet

gvSIG Team: Towards gvSIG 2.4: Changing gvSIG interface. A new set of icons

OSGeo Planet - Tue, 2017-07-25 09:51

gvSIG has used the same set of icons for a good number of years. Therefore, we have made the decision to give the user the opportunity to change themes or icons set easily. To do that, we have created a plugin which we will describe in a post later. Here, we want to show the excellent set of icons that Mario Fèvre from the company TreCC S.A. has been created, as well as the instructions to work with them in gvSIG Desktop 2.4.

In addition to both tool sets, a complete guide for styles has been created. You can check this out here (now in Spanish).

There are two sets, one where the icons size is 16×16 and the other with 22×22. This second one meets the demands of part of the gvSIG community that asked to work with larger buttons.

The two sets can be downloaded in the following links:

Any of them can be installed, once downloaded, by using the “Set administrator > Using file”, so far (they will be also available in the official repository in the final version). You should select either “TreCC-icon-set” … 22×22 or 16×16, depending on your preferences.

Once it is installed, gvSIG Desktop must be restarted. Then, there´s one more step to indicate to the application in case one of the new set of icons wants to be used.

Go to “Preferences > General/Set of icons” and choose the icons set to be used as shown in the picture below:

Then, restart gvSIG Desktop to see the new interface of our favorite GIS. By the way, in the last builts there’s no option to go back and see the traditional set of icons (do not forget that we are in the test phase) although we expect to include this option in the future builts.

Here a short video that shows the new gvSIG Desktop:

Finally, we would like to mention that gvSIG Desktop 2.4 will be launched with the “traditional” set of icons. This is not just the one that most of the users are familiar with but also it is the one that all the existing documents are referred to. However, the new icons will be also at your disposal in the application. Eventually, in the next versions, we will consider the opposite: gvSIG will be able to be released with the new icons set, with the traditional one available.

Filed under: english, gvSIG Desktop Tagged: gvSIG-2.4, Set of icons, symbology
Categories: OSGeo Planet

Free and Open Source GIS Ramblings: Dynamic styling expressions with aggregates & variables

OSGeo Planet - Sat, 2017-07-22 18:56

In a recent post, we used aggregates for labeling purposes. This time, we will use them to create a dynamic data driven style, that is, a style that automatically adjusts to the minimum and maximum values of any numeric field … and that field will be specified in a variable!

But let’s look at this step by step. (This example uses climate.shp from the QGIS sample dataset.)

Here is a basic expression for data defined symbol color using a color ramp:

Similarly, we can configure a data defined symbol size to create a style like this:

Temperatures in July

To stretch the color ramp from the attribute field’s minimum to maximum value, we can use aggregate functions:

That’s nice but if we want to be able to quickly switch to a different attribute field, we now have two expressions (one for color and one for size) to change. This can get repetitive and can be the source of errors if we miss an expression and don’t update it correctly …

To avoid these issues, we use a layer variable to store the name of the field that we want to use. Layer variables can be configured in layer properties:

Then we adjust our expression to use the layer variable. Here is where it gets a bit tricky. We cannot simply replace the field name “T_F_JUL” with our new layer variable @style_field, since this creates an invalid expression. Instead, we have to use the attribute function:

With this expression in place, we can now change the layer variable to T_M_JAN and the style automatically adjusts accordingly:

Temperatures in January

Note how the style also labels the point with the highest temperature? That’s because the style also defines an expression for the show labels option.

It is worth noting that, in most cases, temperature maps should not be styled using a color ramp that adjusts to a specific dataset’s min and max values. Instead, we would want a style with fixed value to color mapping that makes different datasets comparable. In many other use cases, however, it is very convenient to have a style that can automatically adapt to the data.

Categories: OSGeo Planet

GIScussions: Pay it forward

OSGeo Planet - Fri, 2017-07-21 12:53

Pocket Change

FOSS4G starts in Boston in just over 3 weeks time, there will be close on 1000 attendees (could go higher if you are one of the late registrations) learning, sharing, networking, having a bit of geofun, making new friends and building the Open Source Geo community. There will be hundreds of presentations, workshops, keynotes, lightning talks, birds of a feather, meet ups, loads of QGIS and lots of new stuff. So who wouldn’t want to be there?

Look at the map of delegate home countries

Not many delegates from the southern hemisphere are there? Most of the delegates are from the US and Western Europe, which is understandable – a week in Boston at FOSS4G will cost at least $1,500 plus the cost of flights, outside the budget of many people.

Thanks to some generous sponsorship we have been running a FOSS4G Travel Grant Programme to help some FOSS4G contributors and enthusiasts to join us in Boston, we have now made 10 awards to people from the lowest 3 World Bank income categories (that’s mainly incomes of less than $4,000 pa).

There were many more deserving applicants than we had funds to support, so we want to do a bit of crowdfunding to raise money to bring a few more to Boston

  • Every 60 people who donate $25 will enable 1 extra person to attend FOSS4G
  • If everyone who has registered for FOSS4G chipped in just $15 we could bring 10 more people to FOSS4G
  • If you or your company are feeling very generous, you could even sponsor 1 individual yourself
So why should you put your hand in your pocket? Do you remember the person who helped you to get started in geo? Do you remember the buzz from attending your first big geo conference, maybe it was a FOSS4G, maybe it was an ESRI UC, maybe it was an AGI GeoCommunity? Maybe, you don’t even do geo, but you still remember someone who helped you to get started on the path that you are following. Now is an opportunity to “Pay it forward” and help someone else to get started in geo and make a difference in their home country.

Go on, dig deep, dig a bit deeper, you will feel good about your donation and someone else will get the chance to experience the goodness of FOSS4G. So click on the donate button now (the money will go to OSGeo Foundation and PayPal waive credit card charges as they are a NFP)

May the FOSS be with you


Categories: OSGeo Planet

Fernando Quadro: Geolocalização no Hipsters.tech

OSGeo Planet - Fri, 2017-07-21 12:39

Esta semana foi a vez da Geoinformação ser abordada no podcast Hipsters.tech, promovido pela Alura. O episódio #53 foi um bate papo que contou com a presença de Roberto Marin (CTO da Maplink) e Fred Hohagen (CEO e fundador da Maplink) além dos hosts Paulo Silveira e Maurício Linhares.

O bate papo foi bastante interessante sendo discutidos assuntos como Geomarketing, Geolocation, Big data, logística, entre outros bastante relevantes.

Indico aqueles que tenham interesse ouvir o podcast, pois vale a pena. Se você quiser escutar pode iniciar agora mesmo clicando no play logo abaixo:

Categories: OSGeo Planet

Jackie Ng: So ... where's MapGuide Open Source 3.2?

OSGeo Planet - Thu, 2017-07-20 15:25
Here's the story, since I gather not everyone reads the mapguide-users mailing list where I mentioned this subject many months ago.

I've decided (many months ago) to skip on making this release.

The differences between 3.1 and (a 3.2 release if I had decided to make one) is so small that it isn't worth investing the build resources on a 3.2 release cycle.

Since I'm skipping on a 3.2 release, it means that we have a good year-long window of solid development time to get some compelling features into the release after it (currently set as 3.3). Some of this development work is already starting to bear fruit.

Now that's not to say there isn't going to be a MapGuide release sometime between now and when 3.3 is out. I still do hope to put out the (hinted previously) patch releases for MGOS 2.6, 3.0 and 3.1 in between, but that requires me rebuilding my build infrastructure first and that is currently taking a back seat to landing some solid features into 3.3 first, so that's where things are at.

And as always. As these features land, you can expect this blog to talk about it.
Categories: OSGeo Planet

gvSIG Team: 9as Jornadas da América Latina e do Caribe de gvSIG: “gvSIG: Geotecnologias livres e desenvolvimento sem fronteiras”

OSGeo Planet - Wed, 2017-07-19 06:23

De 4 a 6 de outubro de 2017 serão realizadas as 9as Jornadas gvSIG da América Latina e do Caribe (LAC) em Santa Maria (Rio Grande do Sul – Brasil) sob o lema “gvSIG: Geotecnologias livres e desenvolvimento sem fronteiras”, a nova reunião de usuários e desenvolvedores ligados ao software gvSIG organizada no Brasil.

Já está aberto o período para  envio de propostas para comunicações. A partir de hoje as comunicações podem ser enviadas ao seguinte endereço eletrônico: jornadas.latinoamericanas@gvsig.org. Toda as informações sobre as normas para a apresentação de comunicações podem ser consultadas no tópico comunicações. O período de submissão de resumos se encerra no dia 26 de agosto.

O período de inscrições para as Jornadas LAC será aberto no dia 8 de agosto. As inscrições são gratuitas (vagas limitadas).

Filed under: community, events, portuguese, training Tagged: 9as Jornadas LAC
Categories: OSGeo Planet

gvSIG Team: 9as Jornadas de Latinoamérica y Caribe de gvSIG: “gvSIG: Geotecnologias livres e desenvolvimento sem fronteiras”

OSGeo Planet - Tue, 2017-07-18 15:44

Del 4 al 6 de octubre de 2017 se celebrarán las 9as Jornadas de Latinoamérica y Caribe de gvSIG en Santa María (Rio Grande do Sul – Brasil) bajo el lema “gvSIG: Geotecnologias livres e desenvolvimento sem fronteiras”, un nuevo encuentro para el intercambio de experiencias en el uso y desarrollo de gvSIG.

Ya está abierto el periodo para el envío de propuestas para comunicaciones para las Jornadas. Desde hoy pueden enviarse las propuestas a la dirección de correo electrónico jornadas.latinoamericanas@gvsig.org, y serán valoradas por el comité científico de cara a su inclusión en el programa de las Jornadas. Toda la información sobre las normas para la presentación de comunicaciones puede consultarse en el apartado de Comunicaciones de la web. El periodo de recepción de resúmenes finalizará el próximo 26 de agosto.

El periodo de inscripción a las mismas se abrirá el próximo día 8 de agosto. La inscripción será gratuita.

¡Esperamos vuestras propuestas!

Filed under: community, events, portuguese, spanish, training Tagged: 9as Jornadas LAC
Categories: OSGeo Planet

gvSIG Team: Learn GIS for free. Extra Module : GPS and Mobile GIS

OSGeo Planet - Tue, 2017-07-18 12:55

Although “Learn GIS for free” course ended with the tenth module, today we offer you an extra module very interesting for those who are interested in using Mobile GIS to capture field data.

In this module you will know Geopaparazzi. It’s a tool developed to do fast qualitative technical and scientific surveys.

Note 1: We are working on a new version of gvSIG Mobile, based on Geopaparazzi and we hope to be able to give you news soon.

Note 2: It is also interesting that you know that there is a Geopaparazzi plugin in gvSIG Desktop that will be very useful for those who will work with these 2 applications of gvSIG Suite.

Extra 1. GPS System

Extra 2. GPS Survey

Extra 3. GPS to GIS

Enjoy and spread gvSIG Suite!

Giuliano Ramat made this course in the framework of a collaboration between the gvSIG Association and GISMAP.

Related posts:

Filed under: english, Geopaparazzi, gvSIG Desktop, training Tagged: course, free, GPS, survay, tutorial
Categories: OSGeo Planet

Fernando Quadro: MBA em Geociências e Geotecnologias

OSGeo Planet - Mon, 2017-07-17 20:05

Na área de Geociências existem pouquíssimos cursos profissionalizantes, bem como de graduação, e esta é uma área que toma cada vez mais importância. Este curso promove uma visão ampla e traz temas extremamente novos, interessantes e totalmente aplicáveis. A aplicação prática dos módulos apresenta ao aluno uma usabilidade direta do que está sendo proposto aumentando assim as possibilidades profissionais tanto do mesmo como da empresa na qual ele trabalha.

O curso é promovido pelo IPOG – Instituto de Pós-graduação e Graduação, uma Instituição de Ensino Superior (IES) onde o diferencial competitivo tem se dado pelos surpreendentes e duradouros resultados conquistados pelos programas de especialização. Cursos que, na maioria, são inéditos e contam com projetos pedagógicos arrojados, ministrados por um corpo docente altamente qualificado em preparar o aluno com bases sólidas, transformando-o em um profissional de alta performance.

Se você ficou interessado, e quer ter mais informações do curso, como ementa, diferenciais, entre outras coisas, acesse o link abaixo:


Categories: OSGeo Planet

gvSIG Team: Learn GIS for free. Module 10: Digital Elevation Model analysis

OSGeo Planet - Fri, 2017-07-14 10:35

We finish this free GIS course with the tenth module, where we show you how to work with Digital Elevation Models.

Digital Elevation Models (DEMs) are raster files with elevation data for each raster cell. DEMs are popular for calculations, manipulations and further analysis of an area, and more specifically analysis based on the elevation.

To follow the course you need:

10.1 DEM analysis in gvSIG

10.2 DEM derived data

10.3 DEM Visibility

Enjoy and spread gvSIG Desktop!

Giuliano Ramat made this course in the framework of a collaboration between the gvSIG Association and GISMAP

Related posts:

Filed under: gvSIG Desktop Tagged: course, DEM, Elevation Model, free, gis, raster, tutorial
Categories: OSGeo Planet
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