September 2014 Update


Approximately a month ago nucleotid.es was a single page showing a handful of benchmark tables. Since then I have been able to add more features and the website has changed greatly. I will aim regularly write announcements to summarise these changes as nucleotid.es continues to change and improve in the future.

Assembler command bundles

A problem I encountered early on was how to manage running the same assembler in different ways. An example is the spades assembler which has the --single-cell and --careful flags, both of which should be evaluated for their effect on assembly quality. My initial approach was to create a new Docker image for each way of running an assembler. This resulted in Docker images like nucleotides/spades-3-single-cell-careful where command line flags were listed in the name.

This approach was ungainly and I assumed that more complex ways of running an assembler would generate longer and longer names. Furthermore if a new Docker image had to be created for each combination of command line flags then this would result in an overabundance and confusion of Docker images.

Instead, I created Docker images with "command bundles." These command bundles allow the same Docker container to be run in multiple different ways. Using the spades example from above, the spades container can be called on the command line as follows docker run nucleotides/spades default ... or docker run nucleotides/spades single-cell .... The first argument to each container should be the command bundle specifying how it should be run. I believe this simplifies the problem of benchmarking assemblers with multiple different command line options. You can see these command bundles in the second column of each table on the assembler benchmarks page.

Voting on the best assemblers

I have added more reference genome read sets for benchmarking. There are now 16 references, each with a corresponding table on the benchmarks page. A greater number of benchmarks provides more information on how the assemblers perform. If you browse these benchmarks there are visible trends as to which assemblers perform well. Viewing a large number of tables is however not an ideal way to compare assemblers.

I have tried to solve this visualisation problem by treating the benchmarks as an election. Each reference genome can be thought as 'voting' for the Docker image which assembles their corresponding reads the best. The best assembler is then the one that is 'elected' by all the reference genomes. I use the Schulze method for tallying the votes. At present there are the results of two elections on the assembler results page. The first is for the Docker image that produces the best NG50 and the second is for the assembler that produces the least number of incorrect bases.

List of assemblers

I have listed all the assembler Docker images on the assemblers page. This page shows each assembler Docker image and indicates whether an assembler has a homepage and a source code repository. You can see that if an assembler doesn't have a source code repository, such as github or bitbucket, then there is a small red cross. The aim of this is to encourage developers to provide resources related to their assembler for the bioinformaticians. In future I would like to add additional checks like providing a mailing list, an issue tracker and documentation.

Improved website appearance

I have spent some time improving the website appearance. I have limited ability when developing HTML and CSS and this shows when viewing the website on a mobile device. I have however tried to improve the front page of nucleotid.es to clarify the main goals of the project. I created some simple logos in Inkscape which are also visible on the front page. These logos are based on cogs or gears inside boxes, representing genome assemblers inside Docker containers.

No third-party assemblers have been submitted

At present the only Docker images on nucleotid.es are those I have written myself. I would encourage any interested developers to write a Docker image for their own or other assemblers. Creating a working image often takes a some time and so this project will progress slowly if I am writing all the Docker images myself. If you would be interested in developing an assembler image I would be happy to help by providing support through the nucleotid.es mailing list. The more assemblers that are included the benchmarking, the more accurate a reflection of the state of genome assembly this project provides.