Gephi updates with 0.9.1 version

splash091A new Gephi version has been released and can be downloaded from gephi.org. This version is an update from the 0.9.0 version released last December and mostly addresses issues discovered since.

One notable improvement is a new localization: German! Gephi is now localized in nine languages (English, French, Spanish, Japanese, Brazilian Portuguese, Russian, Chinese, Czech and German) and we hope to continue the momentum on this effort in the future.

new_german_l10n

Other notable improvements include a better support for parallel edges, appending to existing workspaces and how filters are saved in .gephi files. More than 60 bugs were fixed with a majority of them reported by the community. Thanks to all users who took the time to help! The complete list of bugfixes and improvements can be found in the changelog on GitHub.

In the next few weeks we would like to focus on documentation as there’s still many features brought in the 0.9.0 version without up-to-date documentation. This is especially important for more complex features such as dynamic graphs, which got a major upgrade.

As usual, please share your experience/feedback on our Facebook group or on Twitter.

A close look at the Gephi user community

Last December we asked Gephi users to participate in a survey. The survey’s main objective was to better understand who users are and what kind of projects they work on. One important dimension we wanted to explore was the diversity of the user community. Through the projects we’ve seen in research and on the web we knew that Gephi users were diverse, but we wanted to quantify it. Ultimately, we aim to make the tool better so it supports users’ needs, but this is a process that requires first a good understanding of who the audience is and what are their objectives. Below we summarized our findings about the profile of users, the types of networks they work with and finally useful usage statistics the community can reflect on.

Profile

The largest share of Gephi users work in academia. The project started in the academic sphere from where it has spread into business, artistic and non-profits domains as well. Working at a profit organization is the second most common occupation, which confirms that network analysis is no longer reserved to scientists.

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Q12. What is your occupation? n=285; multiple choice

Given that the largest group of users works in academia, it is not surprising that the most common title among Gephi users is a researcher.

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Q14. What is your title? n=285; multiple choice

The user community is also widely spread around the world. Users from 46 different countries participated in this study. This confirms the importance of localization for as many languages as possible (Gephi currently supports eight). While many countries were represented by only a handful number of participants in the study, large concentration of users is, as expected, in the US (23%) and in France (15%). Significant presence in France is predetermined by Gephi’s presence in universities and businesses within which Gephi was originally founded.

Networks

Social networks are by far the most commonly analyzed type of networks when using Gephi. 70% say that they typically analyze social networks when using Gephi. Social media and semantic network analysis are also common and typically analyzed by 46% and 43%, respectively. The rest of the networks are less common with ecological network analyzed by about 5% of users.

Despite SNA (Social Network Analysis) being the dominant use there is a large variety of other use as well. That said, networks can be analyzed only if the data are accessible and we (the community) still have work to do to ease network collection and formatting.

We always wondered if given occupations are more likely to work with specific types of networks. Based on this study, some differences exist, but they are not as prominent as we have expected. We found that people working at profit organizations are more likely to use Gephi to analyze business and financial networks. While in total 24% use Gephi to analyze business network, it is 44% among those who work in a profit organization compared to only 12% among those who do not work in a profit company. Differences for other types of networks were not conclusive.

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Q5. What type(s) of network do you typically analyze using Gephi? n=285; multiple choice

Gephi users commonly deal with a wide range of network sizes. Although the typical network has between 100 to 10K nodes, every size from <100 nodes to 1M nodes represent at least 10% of users. In total that is more than 5 orders of magnitude difference in data size, and without taking edges in consideration!

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Q6. What is/are the graph size(s) you deal with when working with Gephi? n=285; multiple choice
Q7. And what is the TYPICAL size of a graph that you manipulate with Gephi? n=285; single choice

While more than half of Gephi users have never used Gephi to analyse dynamic networks, the vast majority of the community is likely to use it in the future.  This confirms the importance of the set of features related to dynamic networks that has long been one of Gephi’s primary focus.

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Q8. Have you ever used Gephi to work with dynamic networks (networks over time)? n=285; single choice

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Q9. How likely are you to use Gephi to analyze dynamic networks (networks over time) in the future? n=285; single choice

Usage

Both online and offline sources are important touch points through which people learn about Gephi for the first time. While web search is the most common way how people find Gephi, word of mouth remains an important channel and is not to be underestimated.

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Q2. How did you first learn about Gephi? n=285, single choice

The community is very diverse when it comes to usage frequency which suggests that Gephi users are likely to have diverse needs. Occasional users are likely to have different expectations from a software than regular users.  About one third uses Gephi at least once a week which confirms that there is a relatively large base of heavy users who use Gephi regularly.

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Q3. On average, how often do you use Gephi? n=285; single choice

Online tutorials and online forums are key sources for users to learn about Gephi. This confirms the importance of creating and updating online tutorials. It also suggests that the community is well engaged to be able to provide answers one another on online forums and groups.

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Q4. What source(s) have you used/are you using to learn how to use Gephi? n=285, multiple choice

Conclusion

This survey is a first, yet important step in understanding the Gephi user community at large. It also gives a general overview of the network visualization and analytics field and we hope this can be useful for others as well. But for us – the Gephi leadership team – this will help us in our future community management efforts. It will also help design a better tool in the future as we better understand its user community.

In addition, talking about what kinds of projects users work on also helps shape the understanding of what network analytics is used for, and ultimately bring more people to the community. In the near future we want to double-down on this topic and start a series of articles highlighting the most interesting projects. Many of the respondents indicated their willingness to share what they have worked on so there’s already plenty to choose from.

Finally, to reflect on the diversity of users we believe it simply reflects that networks are everywhere. Analyzing networks bring insights and answers to many different problems.

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Appendix
  • Survey was conducted among Gephi users community. While the results provide a unique view into the Gephi community it is important to clarify that they are not meant to be representative of the entire community world wide.
  • The survey invitations were distributed throughout the week of Dec 1st 2015 via email, Twitter and Facebook
  • Final data set contains responses collected between Dec 1st 2015 and Dec 23rd 2015
  • A total of 285 participants completed the survey

Gephi 0.9 released: Play with network data again

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We’re proud to announce the release of the next major version of Gephi! This 0.9.0 version has been more than three years in the making but today brings an exciting new life to this project, and the graph/network analytics community at large. You can download it here for Windows, Mac OS X and Linux.

Gephi is the leading graph visualization software – known as the “Photoshop for networks” and is open-source and free. It has been downloaded more than a million times and is used by many scholars and data scientists around the world. This new release brings new features in the area of dynamic networks (i.e. network over time) and major compatibility and performance improvements.

Since the last release in 2013, users were facing compatibility issues with Java, which have been resolved with this release. Development had slow down three years ago but had never stopped. In fact, in March 2013 the time had come to think about what Gephi 1.0 would look like and realize it needed a new core. This was by far the most complex project the team had to overcome but developers had a long-term vision and know that future developments will now rely on a robust and extensible core, with world-class performances.

The world is increasingly complex and interconnected. Gephi’s purpose is to unfold this complex relational data in a way anyone can understand them. It allows you to visualize graph data as a map and create the visualizations to support your narratives. State-of-the-art algorithms make readable layouts, highlighting communities or influential nodes. Visual tools tweak colors and shapes to reveal hidden patterns in the data, helping solving complex problems. More and more network-maps are pictured in online, offline press and other communication media. They spread from science to business, art and activism. People are increasingly exposed to them and learn how to read them. Gephi aims to accelerate this commoditization process by providing free and easy-to-use tools.

What’s new in Gephi 0.9?

The list is too long! The complete changelog for this version can be found on GitHub’s release page.

Next steps

There are a few immediate next steps coming up right after this release. Following-up on the recent plugin development announcement we’ll get in touch with plugin developers and start migrating plugins to this version. There’s more than 80 plugins to update!

Then, we’ll identify and resolve new issues that appeared with this version. A future Gephi 0.9.1 release will come next year to address those.

A Gephi Toolkit release will also be made very soon so developers can update their application built on top of Gephi’s modules. In the meantime, we’re interested in users’ feedback and want to hear from you on Twitter or Facebook. Issues can directly be reported on GitHub as well, where the developers are.

Finally, thanks to all contributors and the community for supporting this project!

Plugin development gets new tools and opens-up to the community

Since the introduction of the Gephi Marketplace and tools such as the Plugins Bootcamp we’ve seen more and more plugins being developed. Even developers with little experience with Java give it a try and succeed in creating their first plugin. We want developers to be productive and make it as easy as possible to get started with plugin development and find help along the way. As the release of the 0.9 version is near, it’s time to review our plan on that matter and upcoming improvements. Here’s the summary:

  • The gephi-plugins base repository (i.e. repository plugin developers fork) is now using Maven for building and is simpler. It contains only 4 files versus 890 for the Ant-based system.
  • All Gephi modules are published on Maven central, making it very easy to inspect and extend.
  • Introduction of a custom Maven plugin designed to facilitate plugin development.
  • The submission and review of plugins will be entirely based of GitHub, making it more scalable and transparent.
  • A new online portal for plugins is coming up with an easier edit experience and new features.

From Ant to Maven

Before diving into plugins, let’s first review what has changed on how Gephi is compiled, built and packaged – as this directly affects plugins as well. Since the Gephi 0.8.2 version we have migrated our build system from Ant to Maven. This is in line with what the Netbeans Platform (i.e. which Gephi is based on) community recommends. It already has increased the level of automation we’re capable of as a result. The main benefits are (compared to Ant):

  • Maven is great at dependencies management. It’s now very clear what version of what library Gephi depends on, making it simpler to integrate. Dependencies are also downloaded automatically instead of being checked in the codebase
  • Unlike the Ant-based system, it’s independent from Netbeans. This allows developers not using Netbeans to develop Gephi and produce a build entirely from the command-line.
  • Gephi modules can now be placed on Maven Central (i.e. global repository where Maven finds its dependencies). This allows plugins to automatically find the Gephi dependencies online, reducing the manual steps at each Gephi upgrade.

Build assistant

There are a few critical steps we want to help plugin developers with and as a result started the development of a custom Maven plugin. This new tool will work behind the scenes when developers build their plugin. No installation or configuration is needed as it comes already as dependency of the gephi-plugins module. It already addresses common pain points and hope to automate more and more of the steps in the future. This is what it can do as of today:

  • Plugin validation: The assistant reviews the plugin configuration and metadata at each build. This allows for instance to check if the plugin depends on the correct Gephi version or remind the developer to define an author or license in its configuration.
  • Run Gephi with plugins: A single command allows to run Gephi with the plugins pre-installed. This makes testing faster than ever when developing plugins.
  • New plugin generator: A step-by-step command-line tool that creates the correct folder structure and configuration to get started.

In the future, we want to rely on this build assistant to further automate the process and for instance do easy migration or code generation. For instance, you could ask to generate a Layout plugin code and configuration. Afterwards, all needed would be to fill in the blanks in the code.

A new way to review and submit plugins

As the number of plugins grows, it’s important to have a clear process how plugins are reviewed and updated. We also want this process to be transparent and open to the community. So far, the process was based on the submission of the plugin binaries with a manual review done by the team. This helped us get where we are today, but we want to get it to the next level and propose to entirely move this process to GitHub – using the pull-request mechanism. This has multiple advantages, listed below:

  • Reviewing new/updated plugins can scale because any developer can read the code and contribute to the pull requests.
  • Developers are already asked to fork the gephi-plugins repository so submitting the plugin via GitHub is a natural extension to it.
  • There’s a clear history of each version, comment and what code has changed from one version to another.
  • It makes it easier to test plugins and detect issues before the plugin is approved.

As part of this migration, we’ll no longer add plugins with closed source code but all existing plugins for Gephi 0.8.2 will remain available. For security and stability reasons, it’s essential that each plugin’s code can be inspected before approval. In order for this to work, all existing plugins not already on GitHub or not forking the gephi-plugins repository will need to migrate. For those already set up, the migration will be easier but Ant-based plugins will still need to migrate to Maven.

To summarize, this is what the new 4-steps process looks like for developers:

gephi-new-plugin-development-process

In the current submission process we ask for additional information such as description, author or license as well as allow the upload of images. Going forward with GitHub, all of these data will directly be defined in the plugin’s configuration making it easier to update.

A new home for plugins (again)

Plugins are currently available online from the Gephi Marketplace, where users could also reach people providing teachings and support.  We have ideas on how to improve these community services and will be migrating them to a new architecture, starting with the plugins. We will tell you more about these changes in an upcoming post but for now our focus is on developing a new lightweight plugin portal that can directly be connected with the data source on GitHub.

Here is a preview of what it will look like for plugin pages:

new-plugin-frontend-preview

 

The content of this website will be automatically updated when plugins are published or updated. The way it works is with Travis CI (i.e. continuous integration platform) simply refreshing the JSON file after changes to the plugin repository on GitHub. Developers can even embed images and write the description in Markdown. This will remove entirely the need for plugin developers to login to the marketplace, update NBMs and metadata.

Migrating plugins

This new Maven-based repository along with the new submission process will be introduced with the Gephi 0.9 release. Let’s review what plugin developers need to know to bring their plugin to this new major version.

As with all major Gephi release, plugins compatibility needs to be evaluated as APIs may have changed. In fact, given this new version is based on an entirely redeveloped core it’s very likely code changes will be required. Hopefully, these changes will often be minor and actually simplify things (i.e less, more efficient code). Documentation will be published on these API changes and core developers will be available to answer questions as well.

Plugin developers will also get contacted regarding moving their code to GitHub with a step-by-step guide. We’re considering adding a migrate command to the new Gephi Maven plugin to facilitate the transition from Ant but that’s an unfunded project at the moment (if you’re interested contributing to that, please let us know). Stay tuned for details right after the release on the path to migration.

And again, thanks for all your hard work on bringing your ideas to life though new Gephi plugins!

 

Gephi boosts its performance with new “GraphStore” core

Gephi is a graph visualization and analysis platform – the entire tool revolves around the graph the user is manipulating. All modules (e.g. filter, ranking, layout etc.) touch the graph in some way or another and everything happens in real-time, reflected in the visualization. It’s therefore extremely important to rely on a robust and fast underlying graph structure. As explained in this article we decided in 2013 to rewrite the graph structure and started the GraphStore project. Today, this project is mostly complete and it’s time to look at some of the benefits GraphStore is bringing into Gephi (which its 0.9 release is approaching).

Performance is critical when analyzing graphs. A lot can be done to optimize how graphs are represented and accessed in the code but it remains a hard problem. The first versions of Gephi didn’t always shine in that area as the graphs were using a lot of memory and some operations such as filter were slow on large networks. A lot was learnt though and when the time came to start from scratch we knew what would move the needle. Compared to the previous implementation, GraphStore uses simpler data structures (e.g. more arrays, less maps) and cache-friendly collections to make common graph operations faster. Along the way, we relied on many micro-benchmarks to understand what was expensive and what was not. As often with Java, this can lead to surprises but it’s a necessary process to build a world-class graph library.

Benchmark

We wanted to compare Gephi 0.8.2 and Gephi 0.9 (development version) so we’ve  created a benchmark to test the most common graph operations. Here is what we found. The table below represents the relative improvement between the two versions. For instance, “2X” means that the operation is twice faster to complete. A benchmarking utility was used to guarantee the measurements precision and each scenario was performed at least 20 times, and up to 600 times in some cases. We used two different classic graphs, one small (1.5K nodes, 19K edges) and one medium (83K nodes, 68K edges) . Larger graphs may be evaluated in a future blog article.

Benchmark / Graph SMALL (n=1490, e=19025) MEDIUM (n=82670, e=67851)
Node Iteration 23.0x 34.6x
Edge Iteration 40.1x 109.4x
Node Lookup 1.6x 2.1x
Edge Lookup 1.2x 2.3x
Get Edge 1.1x 1.2x
Get Degree 2.5x 2.3x
Get Neighbors 3.4x 1.2x
Set Attributes 2.3x 0.1x
Get Attributes 3.3x 4.0x
Add Nodes 6.2x 5.7x
Add & Remove Nodes 1.4x 2.9x
Add Edges 7.7x 3.8x
Add & Remove Edges 3.3x 1.8x
Create View 2851.0x 4762.3x
Iterate Nodes In View 2.7x 1.5x
Iterate Edges In View 11.6x 7.3x
Save Project 2.4x 1.7x
Load Project 0.6x 0.6x
Project File Size 1.9x 1.5x

These benchmarks show pretty remarkable improvements in common operations, especially read ones such as node or edge iteration. For instance, in average it takes 40 to 100 times less CPU to read all the edges in the graph. Although this benchmark focus on low-level graph operations it will bring material improvements to user-level features such as filter or layout. The way GraphStore creates views is different from what we were doing before, and doesn’t require a deep graph copy anymore – explaining the large difference. Finally, only the set attribute is significantly slower but that can be explained by the introduction of inverted indices, which are updated when attributes are set.

And what about memory usage? Saving memory has been one of our obsession and there’s good news to report on that front as well. Below is a quick comparaison between Gephi 0.8.2 and Gephi 0.9 for the same medium graph above.

Benchmark Gephi 0.8.2 Gephi 0.9 Improvement
Simple graph 115MB 52MB 2.2X
Graph with 5 attribute columns 186MB 55MB 3.4X

This benchmark shows a clear reduction of memory usage in Gephi’s next version. How much? It’s hard to say as it really depends on the graph but the denser (i.e. more edges) and the more attributes, the more memory saved as significant improvements have been made in these areas. Dynamic graphs (i.e. graphs that have their topology or attributes change over time) will also see a big boost as we’ve redesigned this part from scratch.

What’s next?

All of the GraphStore project benefits are included in the upcoming 0.9 release and that’s the most important. However, the work doesn’t end and there’s many more features and performance optimization that can be added.

Then, we count on the community’s help to start collaborating with us on the GraphStore library – calling all database and performance experts. GraphStore will continue to live as an all-purpose Java graph library, released under the Apache 2.0 license and independent from Gephi (i.e. Gephi uses GraphStore but not the opposite). We hope to see it used in other projects in the near future.

graphstore-api

GraphStore API, represented as a graph

Announcing Gephi 0.9 release date

Gephi 0.9

Gephi has an amazing community of passionate users and developers. In the past few years, they have been very dedicated creating tutorials, developing new plugins or helping out on GitHub. They also have been patiently waiting for a new Gephi release! Today we’re happy to share with you that the wait will come to an end December 20th with the release of Gephi 0.9 for Windows, MacOS X and Linux.

We’re very excited about this upcoming release and developers are hard at work to deliver its roadmap before the end of 2015. This release will resolve a serie of compatibility issues as well as improve features and performance.

Our vision for Gephi remains focused on a few fundamentals, which were already outlined in our Manifesto back in 2009. Gephi should be a software for everyone, powerful yet easy to learn. In many ways, we still have the impression that we’ve only scratched the surface and want to continue to focus on making each module of Gephi better. As part of this release, we’ve undertaken one of the most difficult project we’ve worked on and completely rewrote the core of Gephi. Although not very visible for the end-user, this brings new capabilities, better performance and a level of code quality we can be proud of. This ensure a very solid foundation for the future of this software and paves the way for a future 1.0 version.

Below is an overview of the new features and improvements the 0.9 version will bring.

Java and MacOS compatibility

This release will restore Gephi’s compatibility with the latest Java versions on all platforms. This will resolve issues our users encounter with Java 7 and 8. Compatibility issues with Mac OS will also be resolved and full support for Retina display screens added.

New redeveloped core

This release will improve performance and reliability by a large margin. The graph structure at Gephi’s core has been redeveloped from scratch and will bring multiple new features, better performance and lower memory consumption. On benchmarks, simple operations such as reading nodes or setting attributes see performance improvements ranging from 2X to 100X. This new core will make many operations in Gephi faster and push the envelope even further in large graphs exploration. Reducing memory usage has also been an area of focus and we have measured a 2X reduction compared to Gephi 0.8.2 on a medium-size graph.

New Appearance module

We’re introducing a new user module named Appearance designed to combine and replace Ranking and Partition modules. Appearance will group in one place all controls acting on the node or edge appearance. The partition capabilities will also greatly improve as part of this new module and a new palette selector is being added. In addition of the default palettes, we’re also adding a cool palette generator designed to find the optimal colors (i.e. partitions can be differentiated from each other). Moreover, it will be possible to “Auto-apply” partitions as well, which is a feature that was only available for Ranking so far.

Appearance Partition Palette selector Palette Generator

Timestamp support

This 0.9 release adds a new way to represent networks over time: timestamps. So far, users could only represent time using intervals and that was cumbersome when the underlying network data was collected at fixed time intervals (e.g. one network per day). Starting with this release, Gephi will support both intervals and timestamps to represent evolving network topology and/or evolving attribute values.

GEXF 1.3 support

The GEXF format is also evolving to its 1.3 version. This version improves the support for graphs over time and introduces the ability to represent time using timestamps rather than intervals. In addition, it’s now possible to set a timestamp or an interval for the entire graph, allowing building collections of GEXF files where each represents a “slice”. This is a common request from the community and we hope this will greatly facilitate the exploration of longitudinal networks.

Multiple files import

With the 0.9 version users will be able to import multiple files in Gephi at the same time. Once the files have been read, two choices are offered, either to import each file into a separate workspace or merge them into the same workspace. The latter is a powerful option when used with dynamic graphs. Indeed, a collection of GEXF files representing the same network over time will be imported in Gephi in a single step.

Import Report Multiple Graphs

Multi-graph support

Multi-graph exampleThis release will bring support for multi-graphs, where multiple edges can exist between two nodes each with a different relationship. Users will be able to import, filter and run algorithms on these graphs but the support for visualizing these graphs will come in a further release.

New workspace selection UI

We’ve heard users’ feedback and the workspace selection user interface will be improved. The new interface will be a “tab-style” interface where each workspace is a tab and switching from one workspace to another only requires a single click. Tabs will be located at the top just under the perspective selection. The previous interface is located at the bottom right corner and will be entirely removed.Workspace Tabs

Gephi Toolkit release

A new release of the Gephi Toolkit, based on the 0.9 version will be made soon after December 20th.

Bug fixes

We’ve done a serious bug squash and already addressed many difficult issues, more to come until the release date.

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Follow us on Twitter or join the Facebook group to get the latest news. If you want to know more about this upcoming release, or want to help out please send us a note.