Author Archives: Jorge

About Jorge

I'm a geogeek living near Valencia, Spain. I work on geomatics and I try to have fun with technology and free software.

Aggregating data for infowindows

Aggregating points: JSON on SQL and loops on infowindows


NOTE: I’ll use CARTO but you can apply all this to any webmapping technology backed by a modern database.

Get all the data

So we start with the typical use case where we have a one to many relationship like this:

    select e.cartodb_id,
           e.displayname,
           e.division,
           e.photourl,
           l.cartodb_id as locaction_id,
           l.location,
           l.the_geom_webmercator
      from locations l
inner join employees e
        on e.location = l.location
  order by location

Easy peasy, we have a map with many stacked points. From here you can jump to this excellent post by James Milner about dense point maps. My example is not about having thousands of scattered points that at certain zoom levels overlap. Mine is a small set of locations but many points “stacking” on them. In this case you can do two things: aggregate or not. When you aggregate you pay a prize for readability: reducing all your data to those locations and maybe using visual variables to show counts or averages or any other aggregated value and finally try to use the interactivity of your map to complete the picture.

So at this point we have something like this map, no aggregation yet, but using transparency we can see where CARTO has many employees. We could also use a composite operation instead of transparency to modify the color of the stacked points.

Stacking points using transparency

Stacking points using transparency

Aggregate and count

OK, let’s do a GROUP BY the geometry and an aggregation like counting. At least now we know how many people are there but that’s all, we loose the rest of the details.

    select l.the_geom_webmercator,
           min(e.cartodb_id) as cartodb_id,
           count(1) as counts
      from locations l
inner join employees e
        on e.location = l.location
  group by l.the_geom_webmercator
Grouping by location and counting

Grouping by location and counting

Aggregate one field

But in my case, with CARTO we have PostgreSQL at hand so we can do way more than that. PostgreSQL has many many cool features, handling JSON types is one of them. Mix that with the fact that almost all template systems for front-end applications allow you to iterate over JavaScript Objects and you have a winner here.

So we can combine the json_agg function with MustacheJS iteration over objects to allow rendering the names of our employees.

    select l.the_geom_webmercator,
           min(e.cartodb_id) as cartodb_id,
           l.location,
           json_agg(e.firstname) as names, -- JSON aggregation
           count(1) as counts
      from locations l
inner join employees e
        on e.location = l.location
  group by l.the_geom_webmercator,l.location

And this bit of HTML and Mustache template to create a list of employees we can add to the infowindow template:

<ul style="margin:1em;list-style-type: disc;max-height:10em;">
{{#names}}<li class="CDB-infowindow-title">{{.}}</li>{{/names}}
</ul>
{{^names}}loading...{{/names}}

List of employees on the infowindow

We could do this without JSON types, composing all the markup in the SQL statement but that’s generating quite a lot of content to move to the frontend and of course making the whole thing way harder to maintain.

Aggregate several fields

At this point we can repeat the same function for the rest of the fields but we need to iterate them separatedly. It’d be way better if we could create JSON objects with all the content we want to maintain in a single output field we could iterate on our infowindow. With PostgreSQL we can do this with the row_to_json function and nesting an inner double SELECT to give the properties names. We can use directly row_to_json(row(field1,field2,..)) but then our output fields would have generic names.

    select l.the_geom_webmercator,
           min(e.cartodb_id) as cartodb_id,
           l.location,           
           count(1) as counts,
           json_agg(row_to_json((
             SELECT r
               FROM (
                 SELECT photourl as photo,
                        coalesce(preferredname,firstname,'') as name
             ) r
           ),true)) as data
      from solutions.bamboo_locations l
inner join solutions.bamboo_employees e
        on e.location = l.location
  group by l.the_geom_webmercator,l.location
  order by counts asc

With this query now we have a data field with an array of objects with the display name and web address for the employee picture. Easy now to compose this in a simple infowindow where you can see the faces and names of my colleagues.

<div style="column-count:3;">
{{#data}}
<span style="display:inline-block;margin-bottom:5px;">
  <img style="height:35px;" src="{{photo}}"/> 
  <br/>
  <span style="font-size:0.55em;">{{name}}</span>
</span>
{{/data}}
</div>

{{^data}}
loading...
{{/data}}

Adding pictures and names

That’s it. You can do even more if you retrieve all the data directly from your database and render on the frontend, for example if you use D3 you probably can do fancy symbolizations and interactions.

One final note is that if you use UTF grids (like in these maps with CARTO) you need to be conservative with the amount of content you put on your interactivity because with medium and big datasets this can make your maps slow and too heavy for the front-end. On those cases you may want to change to an interactivity that works like WMS GetFeatureInfo workflow, where you retrieve the information directly from the backend when the user clicks on the map, instead of retrieving everything when loading your tiles.

Check the map below and how the interactions show the aggregated contents. What do you think of this technique? Any other procedure to display aggregated data that you think is more effective?

Ráfaga

How a daily digest of geospatial links is distributed


TL;DR If you are interested on getting a daily digest of geospatial links subscribe to this mailing list or this atom feed. Take «daily» with a grain of salt.


Over the last six years Raf Roset, one of my favourite geonerds out there, has been sending all the cool stuff he founds about our geospatial world to Barcelona mailing list at OSGeo mailman server. He started circa 2011 sending one link per mail, but in 2013-04-03 he started to make a daily digest. A gun burst in Spanish is called Ráfaga so the joke was really at hand when someone proposed to call those digests that way.

Time passes, September 2014 and I ask Raf to send them also to Valencia mailing list, since most people there understand Catalan and the content was too good to be enjoyed only by our loved neighbours. Finally in January 2015 I decide to start translating them into Spanish and send them also to Spanish and Seville mailing lists.

Then in May I join CARTO and @jatorre thinks is a good idea if I can send them to the whole company mailing list so after some weeks I stop translating them into Spanish. Since that day I only do it English, trying to follow Raf lead everyday translating his mails and forwarding them to CARTO internal mailing list and the rest of the OSGeo ones.

Also at June I decided to put those mails in a simple website so the Ráfagas would also be accessible on GitHub and a static jekyll website so anyone could use the Atom feed to reach them.

Final chapter, in July I also decide to create a dedicated mailing list just for those people who are only interested in receiving those digest mails, obviously thinking in a broader audience, not just my fellow friends from Spain. I think at some point I will stop sending them to the Spanish lists because normally Ráfagas don’t fire any discussion and I’m sending the same message to three lists. To be fair they sometimes provoke discussions at CARTO mailing list. By the way I’m almost certain the full team has a filter to move them to their archives and they think I’m just an annoying spammer (a couple of times I’ve changed the subject just to troll them xDDD).

To conclude I want to post here my daily Ráfagas experience:

  • Raf is an early bird and sends the digest in the morning, I copy the contents into a shared Google Doc where a group of collaborators help me on translating the content. It may seem not a lot of effort, but doing this every single day needs a team. Really.
  • I go to my favorite text editor, put the translated content into a new file and start a local server to check the website renders properly.
  • If everything is OK I copy the rendered content and send it to CARTO and OSGeo mailing lists
  • I commit and Push to the GitHub repo so the website is updated along with the feed.
  • I archive Raf’s mail from my inbox.

Creating a Ráfaga

That’s it. Raf you are a formidable example of perseverance and I hope you’ll have the energy to keep giving us all those contents for many years. Thanks mate!

2016-12-25_222434-selection

Creating a collaborative photo map: From Flickr to CARTO with Amazon Lambda


Phew, it’s been almost two years since my last techie blog post. I know I know, blame on me, I should’ve been writing more here but at least I did some nice posts at CARTO blog. Anyway, It’s Christmas today and because Internet is my playground and any piece of data I can put on a map can be a toy I spent a few hours having some geeky fun.

A few days ago a friend asked I knew any service to create a map of pictures in a collaborative environment. I thought maybe a trendy photo service like Instagram would be a good fit but it happens it’s super restrictive for developers so I headed to the good old Flickr. Flickr is one of those services that are really developer friendly, has a ton of super cool features and a decent mobile application and still, for some reason, it’s loosing its traction. Sad.

Anyway, Flickr has groups so a number of individuals can share geolocated pictures and they can display it on a map but sincerely, it has a very bad interface so probably we can do something better with CARTO. The issue then is how can we maintain an updated map in CARTO from a Flickr Group?

I’m a big fan of unmanaged services. I know there are people that love to maintain their servers but I’m not one of them. If I have to publish a website I try to use something static like uploading the site to Amazon S3 (i.e. my own website) or even better, use Github Pages like the Geoinquietos website. In this case not so long ago the only option to build an application to solve this issue was going to a PaaS service like Heroku, Amazon Beanstalk or Google App Engine, but they are meant for big applications typically involving a database and in general an architecture prepared for bigger things than this simple requirement. Over the last two years a new approach has emerged, a type of service that provides an automatically managed infrastructure to define small functions where each one is aimed to do a single functionality. They only live while they are being executed and afterwards the server is shut down. Amazon Lambda was the first of it’s class but recently also appeared Google Cloud Functions. On both services you can write your function in different languages (Python, Java, NodeJS, even PHP) and they can be triggered from a HTTP call or schedule its execution periodically.

As everything with Amazon, configuration from their website can be difficult and using it from the command line can be heroic. But it was a matter of time that something like Zappa would appear. Zappa is an application that makes deploying Python functions to Lambda dead easy. You basically configure a few settings and code your function and it takes care of the full cycle of deploying, versioning and even you can tail the logs from the cloud into your console in real time.

So to make this as short as possible, I coded a Lambda function that is exposed as a url acting as a proxy to Flickr API. This proxy will take URL arguments (or use some defaults) to retrieve photos information and will output them as a valid GeoJSON file. This allows me to create a CARTO Synchronized Table that updates every hour for example and retrieves the last pictures sent to a group (up to 500, as a Flickr API limitation). This dataset can then be used to create a BUILDER dashboard to present the pictures as nicely as possible.

2016-12-25_225604-selection

Map for the last 500 pictures of the “Your Best Shot of 2016” group on Flickr

Additionally, on this map I kind of reverse geocoded image locations using a world borders dataset so I was able to add a country widget. Apart from that and a bit of CartoCSS to reproduce Flickr logo, the dashboard is quite simple. If you click on any of the images the pop up highlights the image (I love this feature) and you can go and visit the picture page in Flickr.

2016-12-25_225653-selection

Pop up with the picture

But there are other methods on Flickr that returns photos, you can create a map of an account public uploads, or a map of the most interesting photos of the day, by photoset, etc. etc. All using the same proxy!!

I’ve created a github repo with the source code of this proxy (just around 130 lines of code) and more detailed instructions on how to set up your environment to deploy your own version of it on your account and use it in your own integrations. I have more ideas that I want to explore and I’ll try to share it here when I do them.

  • Leverage the Foursquare real time API to create a dataset in CARTO that is automatically updated every time I do a check-in
  • How to configure a scheduled task using the CARTO Engine SQL API. This is a super common use case when you develop projects with CARTO.
  • Create a CARTO Engine proxy to allow anonymous users to perform some tasks only accessible by default to authenticated users.

What do you think of this approach? Have you used Lambda for any other interesting use cases? Do you want me to continue posting on this topic about the other ideas I have? Feel free to comment here or reach me on twitter.

Sevilla

III Edición Geocamp ES


A través de Geoinquietos Sevilla

El próximo 20 de junio se celebrará en Sevilla la tercera edición de la versión española de la Geocamp este año organizada por Geoinquietos Sevilla.

¿Qué es una Geocamp?

– Una desconferencia sobre temática GEO y software libre.
– Evento basado en el concepto de Barcamp y que se viene celebrando desde hace tiempo en Portugal.

El mundo de las tecnologías de la información geográfica (TIG) y el software libre está teniendo cada vez más peso en el mundo en que vivimos, tanto desde el punto de vista personal como profesional. Muestra de eso, en últimos años, se está generando un movimiento muy significativo formado por gente con grandes inquietudes sobre estos temas, a la par que están apareciendo cada vez más  profesionales del sector que participan en proyectos y jornadas de carácter nacional e internacional.

A partir de una de estas participaciones, concretamente en la Geocamp del año 2012 en Campo Maior (Portugal), nace la idea de crear un evento similar aquí en España, donde compartir experiencias y conocimientos sobre temas geo y software libre. Aquí está el germen de la Geocamp española.

Organizada por un grupo de Geoinquietos y apoyados por un conjunto de empresas e instituciones, la Geocamp es un evento con formato desconferenciaque intenta favorecer la participación y la colaboración, puesto que serán los propios participantes de la Geocamp los que conformen el programa de charlas el mismo día de su celebración, justo antes de comenzar. Por supuesto, está garantizada la participación de grandes nombres del mundo del software libre y de la geomática a nivel nacional e internacional.

La Geocamp 2015, que viene precedida de sus anteriores ediciones, realizadas en La Coruña y Vigo, respectivamente, se celebrará en el Parque del Alamillo, parque metropolitano que discurre entre el municipio de Santiponce y la propia ciudad de Sevilla y es de acceso libre (previo registro) y gratuito. Además, se ofrecerá a los asistentes coffe break y almuerzo para reponer fuerzas, regalos, etc., así como alguna sorpresa final. Todo esto gracias a los patrocinadores del evento.

Patrocinadores III Geocamp.es

Para estar atentos a todas las novedades sobre la Geocamp 2015 está disponible su portal web (http://geocamp.es/) y el blog de Geoinquietos (http://geoinquietos.blogspot.com.es/), así como sus perfiles de Twitter y Facebook.

Página de registro: http://geocampes2015.eventbrite.es/

¡Os esperamos en Sevilla!

Fuente de la foto original: https://flic.kr/p/ambxAZ

About Antipodes Map


We’ve been pretty quiet over the last year but that doesn’t mean we’ve been unoccupied. Last summer we (Pedro and me) participated with some friends on a hackathon with a project to give to teachers from our region a tool to help them to relocate, precalculating travelling times with OSRM and some open datasets, one of them a database of schools that our government published as a spreadsheet. That gave us the chance to work and improve our knowledge on the CartoDB Platform, we used their JavaScript API to place a Leaflet map with a parametrized map where the SQL that defined the layer changed depending on user selections. The project is online with some slides with further information, all in Spanish.

De Casa al Cole map

De Casa al Cole Map

After that experience, and thanks to Pedro’s friendship with Carlos Galcerán, a Cuban GIS consultant working in New Zealand, we had the opportunity to put our brains working again for another pet project. The idea is easy, have you ever wondered who is on your antipodes? Yes, three quarters of our planet are oceans so the chance to have an inhabited antipodes is not high but here in Spain, it happens that half of the Iberian Peninsula is antipodal to New Zealand. Join that with the possibility to have data about schools on both countries and well, that’s reason enough for us to start playing. Imagine a geography class on primary school, say in the north coast of Galicia, where kids can contact their antipodal school in Christchurch and practice their English, or kiwis practicing their Spanish, both learning about our cultures, favorite sports, our differences.

We started with a dataset only for Galician schools and end up digging a national registry of schools to create a full dataset of schools for the country. That and the help of Carlos and some help from the Spanish Embassy in New Zealand, gave us all the data needed to set up two tables on CartoDB, so the last piece was just a web interface to develop. With the recent release of OpenLayers 3, and having played with it a bit before, I wanted to do something more complex. We’ll leave the technical details about data and software for another post or two. The application is available at http://antipodes.decasaalcole.com.

Antipodes Map

Antipodes Map

If you like the idea and know someone in New Zealand or Spain that could be interested, please spread the word. And of course, the data is available for reuse on CartoDB and the code is also on GitHub, ready to be reused on other lucky antipodal combinations, we’d love to see both data and software reused and improved!!

Bicipaseo 21Sep

Mapping for the busy cartographer: today moving dots


This article describes how to make a quick map using some nice services we have at our hands. Nowadays almost everyone can create a maps using services like CartoDB, Mapbox, uMap or even Google My Maps. In this case I’ll show how I used the incredible flexibility of CartoDB to combine some Postgres/PostGIS SQL with CartoCSS to animate some dots on top of OSM cartography rendered by Mapbox.

This combination is really unique and convenient, other services only allow you to upload or draw some features and decide some static styling for them. But with this combination, using old SQL you can adapt your data for different uses, with CartoCSS the power of the Mapnik rendering library is available and finally, using the awesome Torque capabilities, animation can be added to our map.

About

The idea of this map is to represent a crowd of cyclists running along the future bike line by the interior ring of the city of Valencia. Tomorrow Sunday 21 September there will be a march to show the interest of city bikers for this line so my idea was to make people think about how the city look like with this (still imaginary) bike lane full of cyclists, instead of cars.

Data preparation

  1. Trace a line that represents the route
  2. Transform the line to EPSG:3857
  3. Make the line denser, placing points every 25 meters using the «Densify geometries given an interval» QGIS processing tool
  4. Convert the line to points (again with Processing) and give them these properties:
    • route it will serve to produce more routes in the future
    • lap to separate the points of the route of other points of interest outside the route
    • id to order the rendering of the points

Visualization

After uploading the dataset to my CartoDB account I’ve created a new visualization that will have these layers:

  1. A blurred line with the route
  2. A point marking the meeting place to start the activity, just in front of the city hall.
  3. The animated points moving over the route

Line

Load the layer paseo and customise the SQL. The SQL is quite self-explanatory, first we filter the points over the line and then we use the ST_MakeLine aggregated function to rebuild our original line.

WITH route AS (
  SELECT *
  FROM paseo
  WHERE route = 1 AND lap>0
  ORDER BY id)
SELECT
  1 cartodb_id,
  ST_MakeLine(the_geom_webmercator) as the_geom_webmercator
FROM route
GROUP BY lap

The styling of this layer is a simple CartoCSS rule with the only trick of a heavy blur filter.

#paseo[cartodb_id=1]{
    line-color: #A53ED5;
    line-width: 8;
    line-opacity: 0.7;
    line-comp-op: lighten;
    image-filters: agg-stack-blur(10,10);
}

Moving dots

This is the most important part of the map, of course. I have a path of points ordered and what I want is to show a more or less crowded ring of people moving. To do it, I’ve created a UNION of ten SELECTs to the table offsetting the id over the full range of id’s. To acieve that I’ve used this long SQL:

WITH route AS (
    SELECT * FROM paseo WHERE lap>0 AND route = 1
),
laps AS (
    SELECT
        cartodb_id, the_geom_webmercator,
        id
    FROM route r1
    UNION SELECT
        cartodb_id, the_geom_webmercator,
        CASE WHEN id  > 25 THEN id - 25 ELSE id - 25 + 254 END id
    FROM route r2
    UNION SELECT
        cartodb_id, the_geom_webmercator,
        CASE WHEN id  > 50 THEN id - 50 ELSE id - 50 + 254 END id
    FROM route r3
    UNION SELECT
        cartodb_id, the_geom_webmercator,
        CASE WHEN id  > 75 THEN id - 75 ELSE id - 75 + 254 END id
    FROM route r4
    UNION SELECT
        cartodb_id, the_geom_webmercator,
        CASE WHEN id  > 100 THEN id - 100 ELSE id - 100 + 254 END id
    FROM route r5
    UNION SELECT
        cartodb_id, the_geom_webmercator,
        CASE WHEN id  > 125 THEN id - 125 ELSE id - 125 + 254 END id
    FROM route r6
    UNION SELECT
        cartodb_id, the_geom_webmercator,
        CASE WHEN id  > 150 THEN id - 150 ELSE id - 150 + 254 END id
    FROM route r7
    UNION SELECT
        cartodb_id, the_geom_webmercator,
        CASE WHEN id  > 175 THEN id - 175 ELSE id - 175 + 254 END id
    FROM route r8
    UNION SELECT
        cartodb_id, the_geom_webmercator,
        CASE WHEN id  > 200 THEN id - 200 ELSE id - 200 + 254 END id
    FROM route r9
    UNION SELECT
        cartodb_id, the_geom_webmercator,
        CASE WHEN id  > 225 THEN id - 225 ELSE id - 225 + 254 END id
    FROM route r10
)
SELECT
    cartodb_id, the_geom_webmercator,
    ((random()*10-10) + id) id
FROM laps

The first with subquery filters the points of the path for this route that feed the next subquery: 10 unions with an id offset separation of 25 points. This subquery is passed to the main query that finally randomizes the id by +-5 positions, that is the order, so the moving dots are not regular, giving a more interesting (anarchic?) effect.

Using the wizard, the main aspects of the Torque animation are set up. It’s important to use a proper resolution, duration and frame count to adjust the rendering to a nice motion. Afterwards some last touches to the CSS to adjust the compositing operation and specially the trails, leaving just one more rendering of a similar point, instead of the default bigger and more transparent feature.

Map {
-torque-frame-count:64;
-torque-animation-duration:30;
-torque-time-attribute:"id";
-torque-aggregation-function:"count(cartodb_id)";
-torque-resolution:4;
-torque-data-aggregation:linear;
}

#paseo{
  comp-op: minus;
  marker-fill-opacity: 1;
  marker-line-color: #FFFFFF;
  marker-line-width: 0.5;
  marker-line-opacity: 1;
  marker-type: ellipse;
  marker-width: 6;
  marker-fill: #41006D;
}
#paseo[frame-offset=2] {
 marker-width:6;
}

Meeting point

To add a feature to the map to render the meeting point, I manually added a new feature to the layer using the CartoDB editor. This feature will have the property lap=0 so it won’t be on the other layers. The SQL for this layer is just a

SELECT * FROM paseo WHERE route = 1 and lap = 0

And the CartoCSS is quite simple with the only important trick to use an external SVG. I’ve used directly the town-hall marker from the Mapbox Maki repository.

#paseo{
  marker-fill-opacity: 0.9;
  marker-line-color: #FFF;
  marker-line-width: 1.5;
  marker-line-opacity: 1;
  marker-placement: point;
  marker-type: ellipse;
  marker-width: 40;
  marker-fill: #3B007F;
  marker-allow-overlap: true;

  marker-file: url(https://raw.githubusercontent.com/mapbox/maki/mb-pages/src/town-hall-24.svg);

Fixed info window

On this layer I’ve also configured an infowindow so when you click on the town hall icon you get some data about the schedule for the event.

Base map

I started using the Nokia day grey base map offered by CartoDB, but after a couple of iterations on the design, I thought it could be great to use a pale purple base map so I went to Mapbox web and quickly crafted a variation of their Mapbox Streets base layer.

Other components

Finally, using the new nice CartoDB layout capabilities I’ve added a simple title for the mobile version of the rendering and a couple of texts and an image (uploaded to imgur) for the logo of the group promoting this activity.

Conclusion

Well that’s all. You can check the visualization here. The job took like 4 to 5 hours. I finished the first animated version in 2/3 hours but you know, devil is in details and designing is always about iterations and refinement. Anyway I’m quite satisfied on the result and I think it serves for its purpose. Definitely I’ll have the opportunity to review and refine this process, as I imagine more routes and bike marches will happen in Valencia where bikers are winning the battle 🙂

What do you think about this visualization. What do you like and what do you hate? Improvements? I’d love to hear your thoughts and comments to make better maps.

Update: almost same effect without crazy UNION

This morning Pedro-Juan asked my, why so many UNIONs? why not using just one long CASE?. After accepting the challenge I did something with CASEs but then realized that I wast just looping over a smaller set of id values, so I could use the modulo function. So the long UNION SQL could be reduced to this easy and simple SQL:

SELECT
    cartodb_id, the_geom_webmercator, 
    ((random()*10-10) + id%3) id
FROM paseo WHERE lap>0 AND route = 1

Wow, that’s so concise compared with the huge SQL above!! Using this id%3 I forced all the values to be just 1,2,3 but with the afterwards random the moving effect is achieved.

The CartoCSS would need also some changes to allow to “fill” the rendering over all the animation time. Check the differences with the above code, specially the number of offsets added:

Map {
-torque-frame-count:50;
-torque-animation-duration:8;
-torque-time-attribute:"id";
-torque-aggregation-function:"count(cartodb_id)";
-torque-resolution:2;
-torque-data-aggregation:linear;
}

#paseo{
  comp-op: minus;
  marker-fill-opacity: 1;
  marker-line-color: #FFFFFF;
  marker-line-width: 0.5;
  marker-line-opacity: 1;
  marker-type: ellipse;
  marker-width: 6;
  marker-fill: #41006D;
}
#paseo[frame-offset=4] {}
#paseo[frame-offset=8] {}
#paseo[frame-offset=12] {}
#paseo[frame-offset=14] {}
#paseo[frame-offset=16] {}
#paseo[frame-offset=18] {}
#paseo[frame-offset=20] {}
#paseo[frame-offset=22] {}

The resultant visualization can be accessed here. Which one do you like more? Do you think it’s worth the simplicity over the (in my opinion) slightly worse effect?

Cartografiando para Filipinas en OSM


Tras una semana frenética de actividad en OpenStreetMap para ayudar en todo lo posible en la crisis por el tifón Haiyan/Yolanda, acabar haciendo una sesión de formación y sobre todo construcción de comunidad en Valencia para mí ha sido toda una experiencia.

Por un lado la increíble respuesta de la comunidad OSM en general a esta crisis (ya casi llegamos a los mil colaboradores), con noticias cada día más esperanzadoras de la cantidad de información que se ha generado en tan poco tiempo, así como la actividad en la lista de correo del equipo HOT. Por otro lado artículos en medios de comunicación como The Atlantic y espectaculares visualizaciones como la del NY Times. Y finalmente la guinda con la sorpresa de obtener una buena aceptación por parte de los estudiantes de cartografía de Valencia para participar en la sesión.

De hecho se nos desbordó un poco el asunto y tuvimos que prometer que repetiremos la actividad la semana que viene en la universidad con ellos para que no vinieran todos hoy. Y menos mal porque hemos casi llenado las instalaciones que tan amablemente nos han cedido la gente de beCode. Creo que vamos a seguir contando con ellos para hacer cosas juntos, ya que casi sin conocernos nos han abierto sus puertas y nos ofrecido de forma desinteresada su local para que hagamos allí lo que se nos ocurra. ¿Mola no?

Al final hemos sido algo más de veinte personas, prácticamente todas noveles en OSM. Tras una charla ultra rápida sobre qué es OSM y qué íbamos a hacer hoy, la gente se ha puesto primero a pillarle en tranquillo a JOSM, y después ya a trabajar. Y la tarea no era para nada sencilla, ya que había que comparar datos anteriores al tifón (la imagen proporcionada por Bing) con la imagen del satélite Pleiades que Esri ha servido para que la comunidad pueda identificar los daños del tifón. Imágenes desplazadas, usuarios que no habían sido muy cuidadosos con la creación de cartografía y algunas nubes más o menos densas han sido los mayores problemas que ha tenido la gente para poder dar de alta nuevos edificios y carreteras y marcar aquellos que han quedado destruidos por el paso de Haiyan.

Como suele ser habitual en estas sesiones, han habido muchas dudas, algún problema técnico y unos cuantos despistes por mi parte pero en general la gente creo que ha entendido tanto la mecánica del trabajo en OSM, como la importancia del trabajo en estas situaciones de desastres medioambientales. Realmente sesiones como hoy hacen comunidad y me alegra ver que las nuevas generaciones de cartógrafos se interesan por estos temas, espero que cale el mensaje y desde Geoinquietos Valencia hayamos contribuido a aumentar la comunidad de OSM en nuestra ciudad.

A ver qué tal nos sale la semana que viene.