Ghostscript 9.07 is buggy

...it fails to convert PDF into page images with "Error: /undefined in --run--".
I downgraded to the Quantal 9.06 edition. Due to dependency issues, a number of packages have to be downloaded (e.g. from http://packages.ubuntu.com/quantal/ghostscript) and replaced:

sudo dpkg -i ghostscript_9.06~dfsg-0ubuntu4_amd64.deb  ghostscript-x_9.06~dfsg-0ubuntu4_amd64.deb  libgs9_9.06~dfsg-0ubuntu4_amd64.deb  libgs9-common_9.06~dfsg-0ubuntu4_all.deb

Prevent ghostscript from getting upgraded immediately with

 sudo aptitude hold ghostscript_9.06~dfsg-0ubuntu4_amd64.deb  ghostscript-x_9.06~dfsg-0ubuntu4_amd64.deb  libgs9_9.06~dfsg-0ubuntu4_amd64.deb  libgs9-common_9.06~dfsg-0ubuntu4_all.deb

The downgrade doesn't seem to affect programs depending on ghostscript like LaTeX or lilypond.

Alekto - dual booting a Zenbook

After Tisiphone, an Asus Bamboo U43JC, bowed out after 2 1/2 years with FUBAR hinges, a 3/4 working LCD panel and a dead battery, the natural choice was to stick to Asus, of course. In fairness, finding something ultraportable with a full metal body and decent screen resolution that's not a Macbook Air and doesn't break the bank doesn't leave you many options beyond a Zenbook. I went for the UX31A DB71 with a 256 GB SSD and i7 3517U processor.

Okular inverse search for multiple editors (e.g. Kile)

Setting up inverse search for Kile/Okular is well documented, e.g. in the official Kile docs. What has always bugged me, though, is that the inverse search editor is set globally in the okularpartrc config file, which means that you can't set up inverse search with different editors for different source code types.
I put together a workaround that changes Okular's editor choice to Kile when Okular is called from Kile by temporarily overwriting the okularpartrc file.

Quick 'n dirty wxPython plot digitiser

There are a number of digitisers out there, but I wasn't happy with any of them - they either gave me weird results or didn't work on Linux. Also I hadn't played with wxPython in a long while.

Dependencies: wxpython, PIL, numpy, scipy.

What it does:

  - manual or automatic (scatter or line) detection of plot points by colour. 

  - axis calibrated ascii (x,y) data export.

Download

  

Compose key in KDE

The compose key is a useful feature if you regularly type international/special characters. Key combinations for pretty much everything can be found here:
https://help.ubuntu.com/community/GtkComposeTable
Enabling the key in KDE is a bit laborious though:
System Settings->Input Devices>Keyboard->Advanced tab->Compose key position.

Scheduled backups to an external hard drive

After a narrowly averted data loss, I decided to schedule daily backups to an external hard drive. The scheduler of choice for this would be anacron, which runs tasks after a specified delay at startup, but only if it it hasn't run before in a specified time period (daily, weekly etc.) This is arguably better than a startup job running at every boot or a cron job running every day at a certain time regardless whether the computer is switched off.
I used unison as the backup synchronisation manager, it has both a GUI interface and an intervention-free console batch mode. Copying exceptions and permissions rules can be easily defined in profile scripts. You can't run this script in pure batch mode, as you have to tell the user to connect the external drive before starting the backup, so I used the Kdialog (zenity on Gnome/Unity) app for pop-up messages.

Resuscitating Nanoengineer on Kubuntu

Nanoengineer has been unsupported for at least five years, and it shows. The 1.1.12 source zip file apparently contains corrupted files, and the code relies heavily on the deprecated python-Numeric.

Movie playback in Latex/Beamer: the current situation with Adobe Reader, Okular and Impress

A few years ago, the only option to include multimedia content in Linux presentations was linking to an external player. While the situation is still far from ideal, we have a few options now:

• Okular has been able to play back movies via mplayer for quite some time now. Features: pause and seek. Downside: poster images appear all black (fixed in KDE 4.10), control bar spacing.
• Adobe Reader can embed external flash players and videos. Features: pause. Downside: Flash, works only with old acroread.
• Open/Libre Office Impress movie playback finally works. Features: presenter console. Downside: plays immediately, pause and seek only outside presentation mode. Also, the LaTeX PDF has to be converted into page images.