• Relative Risk for Dummies

    Posted on January 6, 2012

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    I read a lot of health related studies, and most contain in their conclusion a statistical description of the result. To be able to draw valid conclusions for oneself it is very important to understand what all the numbers mean. I have recently learned all that, so here is an example together with an explanation: [Read More]

  • Health & Software Engineering

    Posted on January 4, 2012

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    One of my main interest apart from software development is health, mainly nutrition but also exercise. I will try to systematically collect my findings and write a health related blog post from time to time. [Read More]

  • Download Bitcoin Logos

    Posted on June 13, 2011

    I have recently joined the bitcoin network, and generated PNG images from these excellent bitcoin vector graphics. I have extracted all relevant images, and converted each one into a PNG with transparancy, and in 60, 90, 300, and 600 DPI. All PNGs are recompressed with optipng -o9 to be as small as possible. [Read More]

  • Smallest working QR Code

    Posted on June 6, 2011

    I’ve been playing a bit with QR code generators, and tried to generated a very small one for this homepage. This is the result: [Read More]

  • svn-shortlog -- Compact & Beautiful Subversion Changelog

    Posted on December 23, 2009

    At work we periodically have short developer meetings to discuss what has happened in the last month. To do this, we go through the bugs in our issue tracking system, and the subversion commits in our repository. Unfortunately, getting an overview of the subversion commits was rather cumbersome, and we could not find any efficient tool to do this. Hence, svn-shortlog was born. [Read More]

  • How to Generate Random Colors Programmatically

    Posted on December 9, 2009

    Creating random colors is actually more difficult than it seems. The randomness itself is easy, but aesthetically pleasing randomness is more difficult. For a little project at work I needed to automatically generate multiple background colors with the following properties: [Read More]

  • iRob Feeder in Action (Video)

    Posted on November 13, 2009

    Finally! PROFACTOR (the company I work for) has decided to get a youtube account and upload some videos. Best of all, this gives me a chance to show off a bit of my (our) work ;) [Read More]

  • Online Password Encrypter for Apache

    Posted on May 22, 2009

    Apache uses (among other hashes) SHA-1 keys for encryption in the .htpasswd. I administer a subversion server, and from time to time I have to add new external users to the system. This is usually rather cumbersome because there is no easy way to get to their encrypted password. [Read More]

  • Beautiful Font Hinting in Ubuntu 8.10 and 9.04

    Posted on January 22, 2009

    Even though I have an LCD monitor, I always have the subpixel hinting switched off because it is just painfully ugly to my eyes. Even when hinting is switched to maximum, the fonts are quite blurry (if you don’t believe me, type xmag and take a screenshot of your font. You can see red and blue linese everywhere). My eyes hurt when I see this. [Read More]

  • Java 1.5 Collections Hierarchy Graph

    Posted on January 5, 2009

    Here is an inheritence graph of some of the more important Java collection classes of Java 1.5. Instantiateable classes are blue and rectangular, abstract classes are just rectangular, and interfaces are elliptic: [Read More]

  • Approximation of sqrt(x) in Java

    Posted on January 5, 2009

    Yesterday I have played a bit with reinventing a fast approximation for sqrt() in Java. This might be handy with J2ME. Wikipedia has a nice article about Approximations that depend on IEEE representation. My version works, and on my Intel Dual Core with an average error of 1.57%, maximum error 4.02% it is 3.5 times faster than the original sqrt. In addition, it is very simple to improve the precision to 0.000161% average error and 0.000775% maximum error which is then 1.56 times faster than Math.sqrt(). [Read More]