Projects

Following a comment from Alexandre on a previous post, I included SQLite in my performance test of database engines running under Java. What prevented me from using SQLite in the previous test is that it’s not a pure Java database and one have to use third-party JDBC driver and implementation classes in order to manage this database engine. IMHO, I also dislike another fact: SQLite does not enforce data type constraints ( and it’s a feature, not a bug) so everything is stored as ASCII string, even if you have very few other “artificial” data types. ...

I’m wondering why Sun chose Derby for its JavaDB … I used JavaDB on a project and my main reason was that it’s embedded in the last Java Runtime Engine (JRE). But I saw a clear degradation of performances (my main criteria is speed) when I had to access the embedded database. And it became worst when I ran my project from a CD-ROM (because it has to be distributed). So I decided to run a small, rough test and compare JavaDB with two other free Java database engines: H2 and HSQLDB. And the results are astonishing: JavaDB seems to be the slowest, hence the worst choice (except for the license). Here are the results (click to show the normal size graphs): ...

There are many websites around that allow you to download videos from YouTube. But it’s not possible to do it directly from YouTube. And you end up with a proprietary Flash video file. Although you can install the Flash plug-in on your computer, there are cases when you don’t want to do so or you are even not able to do so. So, for whatever reason, you want a video from YouTube on your computer in a file format suitable for any kind of multimedia viewer? Here is a small (15 lines) bash script to download and convert a YouTube video you like in standard MPEG format. For that purpose, you’ll need wget (usually, you already have it on your GNU/Linux box) and ffmpeg. ...

Someone hoped my laptop doesn’t make too much noise after I posted a photo of the Tecra logo on Flickr. The short answer is no, it doesn’t make too much noise. At 10cm from the fan output, I can measure 42 dB when the fan is off and 52dB when it’s on. Beside the fact that I don’t hear that noise when I have my headphones, it was not sufficient for me. I wrote small python and gnuplot scripts to collect and display temperature, fan status and load ( .tar.gz file, 1.3ko). During those 2 hours, I checked my e-mails, read news on the web and wrote the OPML output in catrss (that’s why load averages increase at the end, when I’m debugging the software). Here are the results (click on an image to see a larger version): ...

A few days ago, I released the first version of catrss, a tool used to concatenate RSS file(s) to standard output. Today, I added OPML output to this tool. Here it is in version 0.2 (.tar.gz file, 16ko). OPML is a file format first used in a commercial application. Now it’s widely used for the exchange of links between news aggregators. Because of that, I had to implement it in catrss: it’s a potential format for the output of catrss. ...

I’ve just released the version 0.2 of Picklist Editor. Now you have a table of all the proteins on the right of the gel. If you double-click on a cell, you can edit it (note this is not a recommended behaviour). After revalidating the table, your new spot will be included in the gel (and saved to your picklist if you like it). For me, this version is stable and fully functional :-) ...

When you work with 2D gel electrophoresis in proteomics, you end dealing with “pick lists”. For this purpose, I wrote Picklist Editor, a tool to help visualize and modify this pick list. As usual, software and source code are available here. Feel free to use it and report any bug or your wish list :-) (and if you didn’t understand everything above because you are not in the proteomics field, just go to the page too because I also wrote a small introduction) ...

One day, one has to sit at his/her table and try to really understand how to deal with XML. Since I think I can only learn with a project in mind, I took Alexandre Dulaunoy’s mergerss suggestion and tried to develop my own catrss. As the name implies, catrss is one of the many descendants of the cat command. Catrss is used to concatenate RSS file(s) to standard output. In its most simple form, you simply have to give it some RSS files to parse and it will concatenate them for you ; the command is: ...

After discovering the Flickr API, I started coding oncolour this night and here is the result … oncolour is a PHP script that allows you to display your photos from Flickr on your own website and with a specific background colour. It’s better with an example … This URL " http://www.epot.org/flickr/oncolour.php?id=860125589," will give this result: Some other solutions have been developed and used ( example) but this one is really free: free for use (see here how to use it - even for your photos - and a description of all the options) and free to re-use (see here how to download the script and use it on your own server). Feel free to use it! :-)

I told you it’s boring to lay down the whole day (see previous post). And even if I have a laptop, it’s very uncomfortable to type when you are on your bed with a leg on top of 3 pillows. Anyway, I’m not here to talk about my life but to share two small Python scripts. Their goal is to retrieve two television evening news programmes (from RTBF1 and France2, both in French). With that, I can directly watch evening news from my laptop (no need to browse their website nor install ad hoc Firefox plugin; everything can be done from the command line). ...