Archive for the Linux Category

the end of travel?

Posted in Books, Linux, Travel, University life with tags , , , , , , , on June 25, 2017 by xi'an

First came the bad news that travelling [by plane] with any electronic device larger than a small cell phone would be prohibited unless the device was checked in. I first thought this was a sort of weird protectionism for American airlines, since only Middle-East carriers seem to be impacted at the moment, but there are serious hints this could soon be extended to all flights to the USA. And to the UK. And likely to about every flight in a near future. That is fairly annoying and more, not only because it hugely reduces the ability to work on a plane [unless carrying paper printouts of every paper one wanted to read or review during a long flight, until this is as well considered as a fire hazard!], but mostly because quite likely these electronic devices in checked-in bags will be damaged or stolen. So the only convenient [least inconvenient] solution may be to stop travelling with laptops and operate on remote or cheap disposable machines from whenever one is. Since I presume even the smallest PCs like Raspberry Pi’s will be banned at some point. The only good news are for computer companies. And book sellers maybe.On top of this, I learned that the UK has [again!] copied the US in requiring visitors and even its own citizens to open devices to Border or Customs officers. And to disclose social media identities and associated passwords. A British Human Rights activist was recently arrested at London Heathrow for refusing to do so. And I read today that divulging those media IDs are now optional on the visa waiver program and possibly soon to be compulsory. Which sounds insane as a way to fight terrorism as it is obvious to set parallel accounts. And yet another travel nuisance.

At some point in the past, I had mused that we would soon be forced to travel with no personal item, maybe not even our own clothes, but a uniform provided by the airline. With luggages on a drone plane following by a safe margin. The invasion of privacy now contemplated and soon implemented by states that do not any longer seem concerned with Human Right goes way beyond this fantasy scenario. If travelling between countries means a massive reduction of one’s rights and dignity [which is already quite reduced under the current conditions], travelling may soon become a rare occurrence…

the vim cheat sheet

Posted in Kids, Linux, R, University life, Wines with tags , , , on March 18, 2015 by xi'an

Ubuntu issues

Posted in Kids, Linux with tags , , , on February 28, 2015 by xi'an

screen shot with ubuntu 10.10It may be that weekends are the wrong time to tamper with computer OS… Last Sunday, I noticed my Bluetooth icon had a “turn off” option and since I only use Bluetooth for my remote keyboard and mouse when in Warwick, I turned it off, thinking I would turn it on again next week. This alas led to a series of problems, maybe as a coincidence since I also updated the Kubuntu 14.04 system over the weekend.

  1. I cannot turn Bluetooth on again! My keyboard and mouse are no longer recognised or detected. No Bluetooth adapter is found by the system setting. Similarly, sudo modprobe bluetooth shows nothing. I have installed a new interface called Blueman but to no avail. The fix suggested on forums to run rfkill unblock bluetooth does not work either… Actually rfkill list all only returns the wireless device. Which is working fine.
  2. My webcam vanished as well. It was working fine before the weekend.
  3. Accessing some webpages, including all New York Times articles, now takes forever on Firefox! If less on Chrome.

Is this a curse of sorts?!

As an aside, I also found this week that I cannot update Adobe reader from version 9 to version 11, as Adobe does not support Linux versions any more… Another bummer. If one wants to stick to acrobat.

Update [03/02]

Thanks to Ingmar and Thomas, I got  both my problems solved! The Bluetooth restarted after I shut down my unplugged computer, in connection with an USB over-current protection. And Thomas figured out my keyboard had a key to turn the webcam off and on, key that I had pressed when trying to restart the Bluetooth device. Et voilà!

Glibc GHOST vulnerability

Posted in Linux with tags , , , , , on January 28, 2015 by xi'an

screen shot with ubuntu 10.10Just heard about a security vulnerability on Linux machines running Red Hat version 5 to 7, Ubuntu 10.04 and 12.04, Debian version 7, Fedora versions 19 and older, and SUSE versions 11 and older. The vulnerability occurs through a buffer overflow from some functions in the C library Glibc, which allows for a remote code to execute, and the fix to the problem is indicated on that NixCRaft webpage. (It is also possible to run the GHOST C code if you want to live dangerously!)



BibTool on the air

Posted in Books, Linux, Travel, University life with tags , , , , , , , , , , on October 23, 2014 by xi'an

Yesterday night, just before leaving for Coventry, I realised I had about 30 versions of my “mother of all .bib” bib file, spread over directories and with broken links with the original mother file… (I mean, I always create bib files in new directories by a hard link,

    ln ~/mother.bib

but they eventually and inexplicably end up with a life of their own!) So I decided a Spring clean-up was in order and installed BibTool on my Linux machine to gather all those versions into a new encompassing all-inclusive bib reference. I did not take advantage of the many possibilities of the program, written by Gerd Neugebauer, but it certainly solved my problem: once I realised I had to set the variates

check.double = on
check.double.delete = on
pass.comments = off

all I had to do was to call

bibtool -s -i ../*/*.bib -o mother.bib
bibtool -d -i mother.bib -o mother.bib
bibtool -s -i mother.bib -o mother.bib

to merge all bib file and then to get rid of the duplicated entries in mother.bib (the -d option commented out the duplicates and the second call with -s removed them). And to remove the duplicated definitions in the preamble of the file. This took me very little time in the RER train from Paris-Dauphine (where I taught this morning, having a hard time to make the students envision the empirical cdf as an average of Dirac masses!) to Roissy airport, in contrast with my pedestrian replacement of all stray siblings of the mother bib into new proper hard links, one by one. I am sure there is a bash command that could have done it in one line, but I spent instead my flight to Birmingham switching all existing bib files, one by one…

how far can we go with Minard’s map?!

Posted in Books, Linux, pictures, Statistics, Travel with tags , , , , , , , , , , on October 13, 2014 by xi'an

Like many others, I discovered Minard’s map of the catastrophic 1812 Russian campaign of Napoleon in Tufte’s book. And I consider it a masterpiece for its elegant way of summarising some many levels of information about this doomed invasion of Russia. So when I spotted Menno-Jan Kraak’s Mapping Time, analysing the challenges of multidimensional cartography through this map and this Naepoleonic campaign, I decided to get a look at it.

Apart from the trivia about Kraak‘s familial connection with the Russian campaign and the Berezina crossing which killed one of his direct ancestors, his great-great-grandfather, along with a few dozen thousand others (even though this was not the most lethal part of the campaign), he brings different perspectives on the meaning of a map and the quantity of information one could or should display. This is not unlike other attempts at competiting with Minard, including those listed on Michael Friendly’s page. Incl. the cleaner printing above. And the dumb pie-chart… A lot more can be done in 2013 than in 1869, indeed, including the use of animated videos, but I remain somewhat sceptical as to the whole purpose of the book. It is a beautiful object, with wide margins and nice colour reproductions, for sure, alas… I just do not see the added value in Kraak‘s work. I would even go as far as thinking this is an a-statistical approach, namely that by trying to produce as much data as possible into the picture, he forgets the whole point of the drawing which is I think to show the awful death rate of the Grande Armée along this absurd trip to and from Moscow and the impact of temperature (although the rise that led to the thaw of the Berezina and the ensuing disaster does not seem correlated with the big gap at the crossing of the river). If more covariates were available, two further dimensions could be added: the proportions of deaths due to battle, guerilla, exhaustion, desertion, and the counterpart map of the Russian losses. In the end, when reading Mapping Time, I learned more about the history surrounding this ill-planned military campaign than about the proper display of data towards informative and unbiased graphs.

unicode in LaTeX

Posted in Books, Linux, Statistics, University life with tags , , , , , , on October 9, 2014 by xi'an

As I was hurriedly trying to cram several ‘Og posts into a conference paper (!), I looked around for a way of including Unicode characters straight away. And found this solution on StackExchange:


which just suited me fine!