Archive for the ‘Ontopia’ Category

A Million First Steps in Topic Maps [318 Example Topic Maps]

Thursday, January 2nd, 2014

A Million First Steps in Topic Maps by Aki Kivela.

From the post:

British Library released images and information from the 17th, 18th and 19th century books under a title “A million first steps”. The information was released as a series of structured text files placed at the GITHUB. The images were stored into the Flickr. License of the images and the information is public domain.

Wandora Team has converted the data files in GITHUB into the topic map serializations. Topic map serializations are XTM 2.0 formatted and can be viewed/edited in many topic map applications such as Wandora and Ontopia. Information has been divided into separate XTM files each containing information about books published during one year. Filename reflects the publishing year. License of the topic map conversions is same as the license of original data files i.e. public domain. Topic map files doesn’t contain actual images or image files but links to images in Flickr.

Information about the used topic map data model:

  • Each book topic has a basename that is a combination of book’s title and identifier.
  • Each book topic has a subject identifier that is derived from book’s identifier. Identifiers doesn’t resolve.
  • Each book topic has an English display name that is book’s title.
  • If book has a Digital Service Library identifier, it is attached to the book topic as an occurrence. Also, PDF link to the book is attached to the book topic as a separate occurrence.
  • If book has an Ark id, it is attached to the book as an occurrence.
  • Author topic is associated with the book topic.
  • Publication date topic is associated with the book topic.
  • Image topics are associated with the book topic.
  • Place of publishing topic is associated with the book topic.
  • Image topic has a subject identifier and a subject locator that resolve original image file in Flickr.
  • Image topic has a basename that is image’s identifier.
  • Image topic has occurrences for the image number, the page number and the volume number.

What can be done with the topic map conversions of the “Million first steps”? Next chapters describe some ideas.

Wandora and other topic map applications can provide a nice viewer for the book data and especially images. Topic map applications can also provide alternative publishing options that create a WWW site or a specific visualization out of the topic maps.

The user can easily enrich the information captured into the topic map, either manually or semiautomatically. A topic map is fundamentally a graph and topic map applications contain powerful tools to alter and modify the graph. Also, topic maps are incremental and two or more different topic maps can be merged. This enables linked data type merging of book information with some other information sources. Wandora has over 50 different information extractors.


Download XTM conversions of the Million first steps (26.8 MB).

If you have been looking for example topic maps, here are three hundred and eighteen (318) of them. Not every year has a topic map in case you are wondering about the missing years.

Kudos to the Wandora team for splitting the topic maps by year of publication of the books containing the images!

Library interfaces often enable date range searching and that will help identify other materials to associate with the images in question.

Not to mention that annotating images from a particular year will make it easier to make a noticeable impact on the starting topic map.

So, which year are you going to take?

I was going to pick 1611 because of the King James Bible but interestingly, there appear to be no entries for the KJV in that year.

Will have to look around the images at Flickr and pick another year.

Ontopia Runs on Raspberry Pi [This Rocks!]

Tuesday, December 4th, 2012

Ontopia Runs on Raspberry Pi by Kevin Trainor.

From the post:

I am pleased to report that I have had the Ontopia Topic Maps software running on my Raspberry Pi for the past week. Ontopia is a suite of open source tools for building, maintaining and deploying Topic Maps-based applications. The Raspberry Pi is an ultra-affordable ARM GNU/Linux box based upon the work of the Raspberry Pi Foundation. My experience in running the out-of-the-box Ontopia apps (Ontopoly topic map editor, Omnigator topic map browser, and Vizigator topic map vizualizer) has been terrific. Using the Raspberry Pi to run the Apache Tomcat server that hosts the Ontopia software, response time is as good or better than I have experienced when hosting the Ontopia software on a cloud-based Linux server at my ISP. Topic maps open quickly in all three applications and navigation from topic to topic within each application is downright snappy.

As you will see in my discussion of testing below, I have experienced good results with up to two simultaneous users. So, my future test plans include testing with more simultaneous users and testing with the Ontopia RDBMS Backend installed. Based upon the performance that I have experienced so far, I have high hopes. Stay tuned for further reports.

What a great way to introduce topic maps to experimenters!

Thanks Kevin!

Awaiting future results! (And for a Raspberry PI to arrive!)

See also: A Raspberry Pi Supercomputer

Unicode Escape Sequences – LTM & Omnigator

Thursday, November 15th, 2012

While writing a short topic map today I created the topic:

[ru1-1-2-2 : morph = “YM\u0022Y03”;

The basename is based on:


in a standard Hebrew transliteration system.

I substituted the \u0022 Unicode escape sequence for double-quote mark.

Which displayed:


So far, so good.

But I also had:

[ru1-1-13-2 : morph = “&:D\u002274Y”;

The basename being derived from:


Can you guess the character that was displayed without looking?

In case you are wondering, I tried to introduce a space between the escape sequence and “74” (an accent reference) to see if it made any difference:

&:D\u0022 74Y

Same result.

(spoiler space)

The result:

Failed Escape Sequence

Not exactly what I was hoping for.

The real answer is to obtain an UTF-8 version of the file in Hebrew, so I don’t have to worry with ASCII transliteration.

Still, you may encounter a case where you need to use Unicode escape characters.

Take this as a cautionary tale.

Ontopia 5.2.1 and HBase [Port 8080 Conflicts]

Thursday, June 14th, 2012

I have HBase 0.92-1 and Ontopia 5.2.1 installed on the same Ubuntu box. (An obvious “gotcha” and its correction follows.)

The Catalina server will not start with the following error message in {$basedir}/apache-tomcat/logs/catalina.(date).log:

SEVERE: Error initializing endpoint Address already in use <null>:8080

To discover what is using port 8080, use:

sudo lsof -i :8080

Result (partial):

java 5314 hbase

You can either reset the port on HBase or open up {$basedir}/apache-tomcat/conf/server.xml and change:

<Connector port=”8080″ protocol=”HTTP/1.1″


<!– Redefined port to avoid conflict with hbase
<Connector port=”8090″ protocol=”HTTP/1.1″

The comment about avoiding conflict with HBase isn’t necessary but good practice.

(Cloudera has a note about the 8080 issue in its HBase Installation documentation.)

Workshops Semantic knowledge solutions

Thursday, May 10th, 2012

Workshops Semantic knowledge solutions by Fiemke Griffioen.

From the post:

Morpheus is organizing a number of one-day workshops Semantic knowledge solutions about how knowledge applications can be developed within your organization. We show what the advantages are of gaining insight into your knowledge and sharing knowledge.

In the workshops our Kamala webapplication is used to model knowledge. Kamala is a web application for efficiently developing and sharing semantic knowledge and is based on the open source Topic Maps-engine Ontopia. Kamala is similar to the editor of Ontopia, Ontopoly, but more interactive and flexible because users require less knowledge of the Topic Maps data model in advance.

Since I haven’t covered Kamala before:

Kamala includes the following features:

  • Availability of the complete data model of Topic Maps standard
  • Navigation based on ontological structures
  • Search topics based on naming
  • Sharing topic maps with other users (optionally read-only)
  • Importing and exporting topic maps to the standard formats XTM, TMXML, LTM, CXTM, etc.
  • Querying topic maps with the TOLOG or TMQL query languages
  • Storing queries for simple repetition of the query
  • Validation of topic maps, so that ‘gaps’ in the knowledge model can be traced
  • Generating statistics

The following modules are available to expand Kamala’s core functionality:

  • Geo-module, so topics with a geotag can be placed on a map
  • Facet indexation for effective navigation based on classification

The workshops are on Landgoed Maarsbergen (That’s what I said, so I included the contact link, which has a map.)

Ontopia 5.2.1 and the CLASSPATH

Tuesday, April 10th, 2012

In the latest release of the Ontopia suite, you will find the following comments in the installation document:


Now that you’ve set up your CLASSPATH environment variable you can verify it by issuing the following command:

java net.ontopia.Ontopia

It will run and produce the following output if it can find all the classes required:

Ontopia Topic Maps Engine [version]
Success: All required classes found.

If it fails you will get output similar to the following:

Ontopia Topic Maps Engine [version]
Class 'org.apache.log4j.BasicConfigurator' not found. Please add log4j.jar to your CLASSPATH.

The message is hopefully self-explanatory.

Well…, not quite.

At least in the latest release (5.2.1), I encountered the following error message from both Windows and Ubuntu setups:

SLF4J: Failed to load class “org.slf4j.impl.StaticLoggerBinder”.
SLF4J: See for further details.
Exception in thread “main” java.lang.NoClassDefFoundError: org/slf4j/impl/StaticLoggerBinder
at org.slf4j.LoggerFactory.getSingleton(

To cure this problem, I now have the CLASSPATH setting:


I say it cures the problem because I can replicate the problem at will on either box and this fix cures it on both boxes (different JDKs).

So, in addition to ontopia-engine-x.x.x.jar, add to your CLASSPATH:


Norwegian National Broadcasting

Tuesday, April 10th, 2012

Norwegian National Broadcasting

I wrote to Lar Marius Garshol recently about some examples of the use of topic maps in education in Norway. This was one of the resources in his response.

NRK/Skole is an educational site for school children publishing sound and video clips from the archives of the Norwegian National Broadcasting Company, the Norwegian equivalent of the BBC. A team of editors scour the archives to find suitable content, then cut it into clips suitable for use in an educational setting and attach metadata to these clips. The content ranges from interviews with historical figures, clips from the daily news, documentaries, and even comedy gags.

All clips on the site are represented as topics in the topic map, and associated with topics representing people and subjects that the clips are about. In addition, clips are also attached to the programs they were taken from, providing three navigational entry points into the portal: person, subject, or program.

In addition, clips are connected with knowledge goals taken from the national curriculum, which has been published as a topic map by the Ministry of Education. Thus, teachers can navigate the curriciulum for their subject to find clips supporting any particular knowledge goal in the curriculum.

It occurs to me that merging content from this topic map with one on the same news subjects say from Fox News could be quite amusing. Even without translation. I don’t remember if news clips count as “fair use” or not. You would need to check with legal counsel before re-use of Fox content.

BTW, other examples of topic map welcome!

Explore Geographic Coverage in Mapping Wikipedia

Saturday, April 7th, 2012

Explore Geographic Coverage in Mapping Wikipedia

From the post:

TraceMedia, in collaboration with the Oxford Internet Institute, maps language use across Wikipedia in an interactive, fittingly named Mapping Wikipedia.

Simply select a language, a region, and the metric that you want to map, such as word count, number of authors, or the languages themselves, and you’ve got a view into “local knowledge production and representation” on the encyclopedia. Each dot represents an article with a link to the Wikipedia article. For the number of dots on the map, a maximum of 800,000, it works surprisingly without a hitch, other than the time it initially takes to load articles.

You need to follow the link to: Who represents the Arab world online? Mapping and measuring local knowledge production and representation in the Middle East and North Africa. The researchers are concerned with fairness and balance of coverage of the Arab world.

Rather than focusing on Wikipedia, an omnipresent resource on the WWW, I would rather have a mapping of who originates the news feeds more generally? Rather than focusing on who is absent. Moreover, I would ask why the Arab OPEC members have not been more effective at restoring balance in the news media?


Friday, April 6th, 2012


Tutorial from TMRA 2010 by Lars Marius Garshol and Geir Ove Grønmo on the Ontopia software suite.

200+ slides so it is rather complete.

Ontopia 5.2.0

Thursday, February 2nd, 2012

Ontopia 5.2.0

A new release from the Ontopia project has hit the street! Ontopia 5.2.0!

From the “What’s New” document in the distribution:

This is the first release in the new Maven structure. It includes the modularization of Ontopia along with bug fixes along with some new functionality.

The following changes have been made:

  • Ontopia is now divided into Maven modules based functionality. For developers working with Ontopia as a dependency this means that there is a more controlled way of including parts of Ontopia as a dependency. This change does not affect Ontopia distribution users.
  • The distribution has been updated to include Tomcat version 6.
  • The DB2TM functionality has been extended and improved.
  • Ontopoly had several outstanding bugs. Support for exporting TM/XML and schema without data was added.
  • Tolog now supports negative integer values and some basic numeric operations through the numbers module.
  • Ontopia now uses Lucene 2.9.4 (up from 2.2.0).

Thirty-seven (37) bugs were squashed but you will need to consult the “What’s New” file for the details.

Please send notes of congratulation to the team for the new release. They know you are grateful but a little active encouragement can go a long way.

Ontopia now supports numbers in tolog

Monday, September 5th, 2011

Ontopia now supports numbers in tolog

Peter-Paul Kruijsen announces support for numbers in tolog:

Over the past years Ontopia was not able to work with numbers. Sorting e.g. a list of occurrence values could result in ‘123’, ’45’, ‘6’, ’78’. For one of our customers, we needed an implementation that would sort these as ‘6’, ’45’, ’78’, ‘123’, as well as an implementation for adding, subtracting, multiplying and diving numbers.

I have just committed NumbersModule to Ontopia [1]. It will be available in the upcoming 5.2.0 release. With this addition, tolog queries can now work with numbers. It supports these predicates:

  • value(string, result): Parses a string (e.g. an occurrence value) into a number. Pattern and locale are optional, e.g. to parse ‘€ 5.026,34’ for us Europeans
  • format(number, result): Formats a number into a string. Pattern and locale are optional, e.g. to format a number as ‘42.6 %’.
  • absolute(result, number): Calculates the absolute value of a number.
  • add(result, number, number): Adds numbers. Providing more than 2 input values is allowed.
  • subtract(result, number, number): Subtracts numbers. Providing more than 2 input values is allowed.
  • multiply(result, number, number): Multiplies numbers. Providing more than 2 input values is allowed.
  • divide(result, number, number): Divides numbers. Providing more than 2 input values is allowed.
  • min(result, number, number): Calculates the minimum value. Providing more than 2 input values is allowed.
  • max(result, number, number): Calculates the maximum value. Providing more than 2 input values is allowed.



See the post for full details.

Thanks Peter-Paul!


Saturday, March 26th, 2011


From the post:

Ontopia’s developer team is committed to switch from Ant to Maven as build and project management tool for the Ontopia code base. Making this switch has been ongoing work since 2009. This blog post serves as a summary of the work that has been done so far and the work that still needs to be done.

Near the end of the post, you will find:

You can help us by building Ontopia with Maven yourself and either trying out the distribution or the new artifacts as dependencies in other projects. Issues you find can be reported on the Ontopia issue tracker. Keep in mind however that this branch is quite old and might not contain fixes already committed to the trunk.

So, you can have topic map software while learning or practicing your skill with Maven.

Sounds like a win-win situation to me.


Sunday, January 16th, 2011

I saw a tweet dated 2011-01-15 saying that Ontopia was alive.

Since Ontopia is a name known to anyone interested in topic maps for more than 30 minutes, I decided to take a look.

It is indeed the Ontopia software for topic maps.

It was disappointing that the homepage, despite being alive! needs updating. Such as not referring to last year’s TMRA conference.

All the additional resources listed are good ones, but the selection is somewhat limited.

One of my goals for 2011 is to develop a bibliography of topic map papers, presentations, etc.

Will have to see how the year goes.