Tuesday, April 20, 2010

FACETS CodeJam #4 registration now open

Registration is now open for the 4th Annual FACETS CodeJam meeting (http://neuralensemble.org/codejam4), which will take place June 22nd-24th, 2010 in Marseille, France.

The goal of the FACETS CodeJam workshops is to catalyze open-source, collaborative software development in computational and systems neuroscience and neuroinformatics, by bringing together researchers, students and engineers to share ideas, present their work, and write code together. The general format of the workshops is to dedicate the mornings to invited and contributed talks, leaving the afternoons free for discussions and code sprints.

For the 4th FACETS CodeJam, the main theme of the meeting will be workflows: what are the best practices for combining different tools (simulators, analysis tools, visualization tools, databases etc.) to ensure the efficient and reproducible flow of data and information from experiment conception to publication and archiving? Our invited speakers include:

• Dr Juliana Freire, who will talk about scientific data management, workflows and provenance, and give a demonstration of the VisTrails system.

• Dr Hugo Cornelis, who will talk about simulation project workflows in the GENESIS 3 simulator, and give a GENESIS 3 demonstration.

• Dr Gael Varoquaux, a primary contributor to the MayaVI 3D visualization tool for Python, will talk about analysing and modelling spontaneous brain activity in neuroimaging with

We invite contributions on any topic related to software in neuroscience, but especially on topics related to the main theme - if you think you have a good system for managing your workflow, please come and share it with us. If you have ideas for organising code sprints, whether a feature that you would like to see added to an existing tool or an idea for new software, please also let us know.

The meeting is being organised by Andrew Davison, Abigail Morrison, Eilif Muller and Laurent Perrinet.

Registration & Further Information

The registration deadline in 4 June 2010, and is limited to 40 participants.

Please consult the meeting website at


for registration and further information.

Tuesday, April 6, 2010

Tracking computational experiments with Sumatra

“I thought I used the same parameters but I’m getting different results”

“I can’t remember which version of the code I used to generate figure 6”

“The new student wants to reuse that model I published three years ago but he can’t reproduce the figures”

“It worked yesterday”

“Why did I do that?”

We would like to announce the release of version 0.1 of Sumatra, a tool for tracking computational experiments and analyses so as to be able to easily replicate them at a later date.

Replication of computational experiments or analyses ought to be easy, given that computers don't suffer from the problems of inter-subject and trial-to-trial variability that make reproduction of biological experiments so challenging. In general, however, it is not easy, perhaps due to the complexity of our code and our computing environments, and the difficulty of capturing every essential piece of information needed to reproduce a computational experiment using existing tools such as spreadsheets, version control systems and paper notebooks.

The aim of Sumatra is to record as much as possible of the experimental context (software versions, parameters, dependencies, platform information, what files were produced, etc.) automatically, and make it easy to annotate the record with information that cannot be obtained automatically (why the simulation or analysis was performed, tags for later searching, etc.).

Given the large differences in the workflows of different researchers (command line, GUI, batch-jobs (e.g. in supercomputer environments), or any combination of these for different components (simulation, analysis, graphing, etc.) and phases of a project), it is difficult to provide a one-tool-fits-all solution, therefore Sumatra provides the core functionality as a Python package on top of which various different interfaces can be built.

Sumatra currently provides a command-line interface and a rudimentary web interface; we hope that people will also be interested in incorporating Sumatra's functionality within their own tools.

Sumatra 0.1 may be downloaded from the INCF Software Center or from PyPI.

For more information and documentation, check out https://neuralensemble.org/trac/sumatra/.