This version does not provide any major, user-visible features but is mainly a re-implementation in the Ruby programming language. Since Mac OS X 10.5 Apple ships the operating system with a full Ruby installation and also includes the RubyCocoa bridge for interfacing Ruby code with Cocoa and the OS X Frameworks. wkpdf uses this bridge for accessing the WebKit framework for rendering HTML as PDF.

The new wkpdf version provides the same features as the previous Objective-C version of wkpdf, but provides a simpler installation procedure. Also, the source code of the project is now hosted on github.com and I hope that this will encourage other developers to contribute to wkpdf. The old wkpdf website wkpdf.plesslweb.ch and the Subversion repository http://svn.plesslweb.ch/wkpdf will be discontinued.

For the impatient among you, you can install wkpdf with the following command:

sudo gem install plessl-wkpdf --source http://gems.github.com

For more information about wkpdf and how to use it, please refer to the brand new wkpdf website at http://plessl.github.com/wkpdf. Developers can browse wkpdf’s latest source code and clone or fork the wkpdf git repository at http://github.com/plessl/wkpdf/tree/master.

I hope you enjoy the new version and I’m looking forward to your feedback.

It gives us great pleasure to announce our integrated issue tracking system! On repository pages you’ll now see an “Issues” tab in the top menu.

I have been longing for this feature for a long time. Time to say goodbye to my privately hosted Trac installations.

Based on this style I created plainyr-rev.bst which uses plain formatting, i.e., the references are simply numbered, and sorts the references with the most recent references first.

You can download this style from my latex-goodies git repository at github.com. If you are not a git user yet, you can get a tarball of the files by using the download button.

I hope you find this style useful.

It’s been a couple of weeks since I’ve finished reading the book “Cosmic Jackpot” by Paul Davies (ISBN: 978-0618592265) and I’m still impressed by this wonderful book. Paul Davies is physicist and cosmologist and has written a number of popular science books on cosmology. In “The Cosmic Jackpot” Davies discusses one of the fundamental questions of cosmology and philosophy: “Why is the universe fit for life?”

Before discussing possible answers of why the universe allowed for the development of life, Davies’ book takes the reader on a journey and explains the basic concepts of particle physics and cosmology. While I’ve read a number of articles on these and related topics, I think the Davies’ explanations are much more clear and to the point than many other articles. Davies has an unusual talent of giving the reader an introduction almost without any mathematics, but avoids falling into the trap of oversimplifying the topics.

Davies explains the development of the universe from the big bang to today. He explains why the development of life in the universe critically depends on specific properties of the universe, for example the distribution of mass after the big bang, the weight of subatomic particles, or the value of certain physical constants. Thought experiments of physicists have shown, that if these properties would differ only sightly from their actual values, the development of life as we observe it today would be impossible. Consequently, the development of life could have been pure coincidence.

This observation has puzzled numerous physicists and philosophers. Some have rejected the idea of life being a product of coincidence, some have been motivated to work on theories that explain the existence of life in the universe, without blaming it on pure coincidence. Over the course of the book Davies introduces a number of these theories that range from “everything is coincidence” over the “multiverse theory” that predicts an infinite number of parallel universes, an explanation relying on an external god-like creator to the belief that the universe is only a projection of our mind. Being a physicist by profession Davies stresses the theories that base on a solid mathematical foundation. But he also provides some insightful discussions of the more philosophical or even religious approches for an explanation of life from the perspective of a scientist.

I found reading the book very inspiring. It provides a readable and entertaining introduction to cosmology and discusses some of the recent ideas on how the universe can be explained. I can highly recommend reading this book.

The following list presents a choice of my favorite MAC applications (in alphabetical order):

• BibDesk
• Cocoabooklet
• CSSEdit
• Flip4Mac
• iStopMotion
• Macports
• MarsEdit
• NetNewsWire
• OmniFocus
• OmniGraffle
• OmniOutliner
• Perian
• Quicksilver
• Skype
• Skim
• SSH Keychain
• SuperDuper
• TextMate
• TubeTV
• Tunatic
• VLC Videoplayer

Plugins für Mail.app:

• GPGMail Plugin
• Mail Act-On
• Mail Tags

I don’t longer use these applications, that were still on my list last year:

• Carbon Emacs I have completely moved to TextMate. Although Emacs was my beloved editor for more than 10 years, I did never long back for Emacs. In particular I fell in love with my new LaTeX workflow based on TextMate and BibDesk.
• Kinkless GTD obsoleted by OmniFocus
• TeXniscope obsoleted by Skim
• PdfView obsoleted by Skim

Until the advent of CUDA, using the massive parallelism of the GPU for general purpose computations required to disguise the computations as OpenGL commands. The advent of CUDA greatly simplifies this process and allows to directly program the GPU in a multi-threaded programming model in C (with some extensions).

I looking forward doing some experiments with CUDA on my Mac. If you already gave CUDA a try on Mac OS X, I encourage you to share your experience in the comments to this post.

Unfortunately, a change in the WebKit version shipped with Leopard has broken wkpdf on Leopard. Leopard users of wkpdf will be glad to hear, that starting with version 0.2.0, that has just been released, wkpdf will be Leopard compatible.

You can find more information about wkpdf on the wkpdf website.

Fortunately GA allows for tracking a click on a link manually by attaching to each link that should be tracked a onclick JavaScript action which calls the function urchinTracker(arg). GA stores the argument “arg” that is supplied to this function.

Hence, for tracking outgoing links there are two possiblities: a) add a JavaScript onclick action to all links, or b) generate the onclick action automatically with some JavaScript magic, like will explain in the following recipe:

• Download the JQuery libary from http://www.jquery.org. The following examples assume, that the library is installed under the relative path “js/jquery.js”.

• Add the following JavaScript code to the header of your HTML page:

    <script type="text/javascript" src="js/jquery.js"></script>
    <script type="text/javascript">
    
    $(document).ready(function() {
      $("a.track").click(function() {
        var prefix = "link/"
        var msg = $(this).attr("href");
        re = /^(\w+):\/\//;
        tracking_url = msg.replace(re,"$1/");
        urchinTracker(prefix + tracking_url);
      });
    });
    </script>

• Add a class=”track” attribute to each link (<a> element) that shall be tracked, for example: <a href="http://www.test.org/lib/paper1.pdf" class="track">PDF<a>. Since links can be assigned an arbitrary number of class attribute this method can be applied universally.

• The required onclick action is dynamically generated using JQuery. The use of JQuery ensures that this method works with all major web browsers. The onclick action that calls Google Analytic’s link tracker is only added for elements that have a class="track" attribute. These elements are selected by the XPath expression a.track.

• The argument for the link tracker is generated from href attribute of the URL. The URL is reformatted, such that it looks like a path. Additionally, the URLs are prefixed with a path component that specifies the protocol. For example http://www.test.org/lib/paper1.pdf is transformed to the “path” link/http/www.test.org/lib/paper1.pdf.

Now everything should be setup fine and you will be able to track clicks to your outgoing links in Google Analytics.

While this method is a significant improvement over the default behavior of Google Analytics, it is still not perfect. Tracking the download of document only works if the user is loading the document directly in the browser by clicking on the link. If the user instead uses the “Save as..” action of the context menu or just copies the URL and downloads the file otherwise, the download will not be registered. One solution would be the use of download wrappers, as they are used by sourceforge and others, but I find these wrappers annoying. If you have an idea how to improve the proposed method without using wrapper pages, please let me know in the comments.

With this recipe, you will be able to easily export your emails from Outlook Express and import them to Apple’s Mail.app but also to almost any other email program. The trick is to migrate the emails using an intermediary IMAP email account.

A short primer to POP and IMAP email accounts

Most free email services only support the POP protocol for accessing emails. When accessing your email with POP, your email client downloads every new email from the email server of your provider first. The emails are stored only on your local computer. This is an advantage for your email provider because the provider must not provide storage space for all of your emails on his server but only a rather small storage for buffering your new emails until your email program downloads them. For you as user POP has a number of disadvantages. The most serious disadvantage is that you can store your emails only on one computer because the emails are removed from the server at retrieval.

The IMAP is the much more powerful successor to POP. With an IMAP email account, all emails stay on the server and your email client is only downloading a copy of the emails. This allows you, to access your emails from multiple computers, for example, at home, at the office and with webmail, without every having to worry about synchronization. You can even create mail folders on the IMAP server, which are also synchronized between all email clients. While IMAP is a big advantage for you, IMAP consumes more storage and computing resources at your email provider, since all of your emails are stored on the server. This is the reason, why most free email services don’t offer IMAP accounts.

Since POP and IMAP are widely used, almost every email client–even Outlook Express–support both protocols.

Migrating Emails using an intermediary IMAP account

Given this preliminaries about IMAP, you will probably already guess how emails can be exported from Outlook Express. Yes, we will use an intermediary IMAP account for that. Outlook Express allows for moving and copying Emails between accounts, hence we can move all emails from a POP mailbox and local mail folders to an IMAP account and vice versa:

• The first thing you need is an email account with IMAP support. For example, the following providers offer free IMAP email accounts: GMX, FastMail or AIM Mail. The services differ mainly in the size of the IMAP storage space that is offered.

• After creating for your IMAP account, you need to add this account to Outlook Express. Start Outlook Express and choose Option “Accounts” from the “Tools” menu. Click “Add” “Mail…” to bring up the Internet connection wizard. Here you need to fill in the name of the data for your email server, which you have received from your email provider.

• Now you are ready to start the migration. Outlook Express will show both email accounts, your old POP account and your new IMAP account. You can start moving emails from your POP account to your new IMAP account with drag and drop. You can also move local folders to the IMAP account. Be patient, uploading your emails to the IMAP server can take a long time, since the Internet uplink for DSL and Cable modems is generally much slower than the downlink.

• After you have moved (or copied) all of your emails to the IMAP server, you need to setup your IMAP account also in Apple Mail.app (or any other Email client). You add a new mail account in the “Account” preference pane of Mail. Mail will then import all emails from your IMAP account. If you chose to use the new IMAP account and the corresponding email address as your standard account, you are done now. If you would like to stick to your previous POP email account, continue with the next step.

• Setup your POP account in Mail. You can now move email from your IMAP account to the Inbox of your POP account. A local mail folders can be created with the menu “Mailbox” → “New Mailbox…”. Chose location “On My Mac” to make the folder local. You can now move emails from the intermediary IMAP account to your local folders.

I hope you find this hint useful. I know that the hint is obvious once you know it. But I have wasted way too many hours helping some of my friends migrating their Outlook Express email with other methods, before coming up with this idea.

wkpdf now allows for selecting the paper format and orientation for the PDF output. For example, you can store a A5 landscape version of Apple’s developer website with:

wkpdf --source http://developer.apple.com --output out.pdf --format A5 --landscape

You will notice, that the default page borders are a little too large. A future release of wkpdf will allow you to use custom page borders.

Further, I have improved the parsing of command line arguments and the handling of errors. wkpdf now properly sets the exit code on failure and success, which allows scripts to determine whether the PDF conversion was successful.