Maps for Linux & Ubuntu


Everyone uses digital maps these days, I assume. At least I do. Since I’ve been using them more often lately, I checked if there are any apps for Linux and especially Ubuntu. The search returned 4 apps.

Maps (aka gnome-maps)

is a map application for GMONE. Its use is slick and fast. It is supposed to be simplistic
Search and directions is functional (based on MapQuest if I’m not mistaken) but geolocation isn’t. Moreover, the satellite imagery is not available at high resolution.


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Solution for “Error interpreting JPEG image file (Not a JPEG file: starts with 0x89 0x50)”


I recently faced a problem opening some JPG images that I have downloaded somewhere over the internet, probably Twitter. So I though I’d share the problem and the simple solution.

When I tried opening an image I got the following error

Error interpreting JPEG image file (Not a JPEG file: starts with 0x89 0x50)

As the error states I was trying to open an image with a JPEG extension but which was not actually a JPEG image. To further verify this and know the actually format I ran this command in the terminal:

file file_name.jpg

which will give you something like this:

PNG image data, 346 x 480, 8-bit/color RGB, non-interlaced

The solution was to imply replace .jpg or .jpeg with the appropriate format, .png in this case.


I can’t open .jpg files, what to do?, Ask Ubuntu
Why am I getting the error: “Not a JPEG file: starts with 0x89 0x50”, StackOverflow

Installing Some Basic R Packages in Ubuntu


The following is how I configured my R workspace (and Rstudio) and this was first shared on a Coursera’s “Getting and Cleaning Data” course forums.

First make sure that R is version 3+. If not update it according to this stackoverflow question.

Java for rJava

Install Java (needed for rJava) first from a terminal:

sudo apt-get install openjdk-6-jre

which will install openjdk-6-jdk.
If this doesn’t work install all its packages:

sudo apt-get install openjdk-6-*

OR you might prefer openjdk-7-jdk

sudo apt-get install openjdk-7-*

You should find that it is installed using this command:

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Mainframs, Unix, CERN computing center, Ubuntu driving Mercedes-Benz


Here’s a couple of interesting videos I’ve watched recently:

Mainframes and the Unix Revolution

If you liked this video, I suggest you read the book “Turing’s Cathedral”. Check the review.

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Take care of your eyes at the screen with Redshift

Before Redshit I was using f.lux [1] which seems to be broken in Ubuntu’s Unity. I searched for an alternative & found positive reviews about Redshift, which is inspired by f.lux.
By default, redshift fetches your approximate location using the internet (geoclue method) & uses it. if you prefer to manually set it, check the help. And if you, like me, prefer it to use a preset location &/or other configuration (without having to do it every time you run your system), create a text file named redshift.config under your ~/.config/ directory. You can do this from the terminal:
cd ~/.config/
gedit redshift.config
In this file, copy & edit the content below:

;This is a configuration file for the screen color temperature adjuster Redshift.

;Copy this file to your ~/.config/ directory for redshift to use.
;All lines starting with a semicolon areignored (e.g, adjustment-method).
;To change your location, edit the lat & lon numbers. If these two lines are set to be ignored, redshift will fetch your location using the internet.

; Global settings

; The location provider and adjustment method settings are in their own sections.
Make sure to edit the numbers in the last two lines to correspond to your location, before saving & exiting the editor.
This way, every time redshift runs, it uses this configuration file. If you want it to automatically run on startup, add it to your Startup Applications (command: gtk-redshift for the gui & redshift for the cli).
Unlike f.lux, redshift only has a “toggle” option in the gui. The toggle toggles redshift on/off in case you need to. Other preferences are edited from within the configuration file or from the terminal.
 I’d like to thank the the code author, Jon Lund Steffensen, for making this tool; It is, to my knowledge, the only alternative to f.lux for Linux.
That’s basically it for now. May your eyes stress less while you work!

Thanks for reading

Compiling Muesli Fortran


Here is the code you need to compile and install the free numerical and graphical MUESLI library, developed by Édouard Canot [1].

sudo apt-get install 'libatlas-dev liblapack-dev zlib1g-dev libreadline6-dev imagemagick  
libx11-dev libpng12-dev g++ gfortran' #installing dependencies
 Note: for Ubuntu 10.04 replace “libatlas-dev” by “libatlas-headers”)
tar xvfj muesli-linux-all-2.6.3_2012-05-03.tar.bz2 #untar

cd muesli-linux-all-2.6.3_2012-05-03/GNU_GFC
./configure --f90=gfortran --blas=/usr/lib/ --lapack=/usr/lib/lapack/ #configuring

make -s distclean #clean your distribution from previous installation
make -s (or for detailed output: make MODE=verbose) #compiling; this will take some time

cd tests #testing
make #make the test files
./run_all #run all the made test files

cd ..
make install #installing

cd tests/fgl #testing fgl
make #make the test files
./run_all #run all the made test files

And here’s a video on how to do that [1]:

For further help, please contact MUESLI’s author from the respective homepage [2].

[2] MUESLI library homepage:

Ubuntu 12.04 & Cinnamon

Hello again,

Precise Pangolin

Those who will try Ubuntu 12.04 & have a multitouch touchpad will notice the new feature (when enabled)!
Some not very apparent new features (relative to 10.04 & not 11.04 or 11.10!) are:
  • Installation time (i.e; start of copying files to notification or required reboot): 6~7 minutes.
  • Properties of an image in the image viewer gives you the folder name the image is located in & the ability (which I like) to open this folder by clicking the name.
  • Two-finger scrolling: In the “Mouse and Touchpad” settings, under Touchpad I enabled horizontal scrolling (which I do not understand why it is not enabled by default) & chose “Two-finger scrolling” instead of “Edge scrolling”. The latter was not comfortable in my case; I sometimes couldn’t lock the scroll & use it, but with the two-finger option (which needs some time to get used to) is much better; I can now use two fingers anywhere on the pad to scroll not just verticall or horizontally but in any direction (i.e; both vertical & horizontal).


I’d also like share with you the relatively new desktop graphical user interface (GUI): Cinnamon. Below are two images of the desktop, which unlike Gnome 2 which has two panels, has only one main panel.
Cinnamon might very well appeal to Gnome 2 users who do not wish to switch to neither Gnome 3 that Fedora employs nor Ubuntu’s new Unity.
A particular feature employed in Cinnamon that adds to Gnome 2 that I really appreciate is a graphical feature. What I really like is the Mac-like drop-down window when saving a file. All I can show you is the screenshots below:
The default GUI for Mint 12 with its default one-panel look.
Cinnamon panel settings
Cinnamon panel settings
It is very easy to edit the panel settings &/or add a new panel.

If you like what you see & would like to try it out, you can install it on Precise Pangolin (12.04 LTS) as follows (read note below first):

Note: Keep in mind that Cinnamon is a newly born project & so it is under active development &  you might possibly face bugs (but keep in mind ithat it has already the default for Mint 12). It deserves to be tried; Note that the above ppa is the “stable” repository.
Personally, I guess It is going to be second after Unity, though I am also testing LXDE, XFCE, fluxbox, openbox,…
Update (2012-06-05): For more about Cinnamon, check the article “Cinnamon 1.4” by Tim Schürmann and Kristian Kißling from Linux Magazine.

If you really enjoyed Cinnamon, I highly suggest that instead of installing Ubuntu & Cinnamon that you install the Ubuntu-based Linux Mint (or its other alternative, the Debian-based Linux Mint Debian Edition -LMDE).

Thanks for reading 🙂