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SIENews

The newsletter of the SIE de Investigación y Enseñanza N. 56 - November/December 2016

"Práctica de Empresa" internships at SIE

During the last month we have had two ULL fourth-year physics students working with us under the "Práctica de Empresa" program, one of them in collaboration with the Sky Quality Group. Their internship period is almost finished, and the results of their work will be presented on Wednesday 21st of December.

David has been working on developing an aggregate calendar of astronomical talks broadcast live. First, he wrote a Python program that reads and parses the seminars' schedule from those research centers that broadcast their talks and publish their calendars in a suitable format (such as RSS or fixed-format HTML), and store this information in a local database. Now, he's working on the PHP code to display the whole list of all seminars in a weekly or monthly view, together with a search tool (some customizations are also possible). We expect to incorporate this new interesting application in the SIE website or in iactalks; more info and details will be offered in the next SIENews issue.

Pablo has been working with the "Sky Quality Group" and us on a tool to publish online the data received from the Automatic Weather Station Las Moradas, located at the ORM. Building on partial work already done in this project, he has focused on finishing all pending tasks in both data gathering process and web visualization, in particular making a robust connection to the AWS, getting the raw data and processing them so that they can be stored in the database, and finally adapting the existing web site to the new requirements. Last but not least, thanks to Pablo's work, the processed data, besides being displayed on the web, can also be retrieved directly by other groups that wish to use them, for instance the GTC staff.

Supercomputing statistics

We have computed the usage statistics of our supercomputing resources, from January 1st to December 19th 2016.

HTCondor has been used for 1,509,884 horas, which is equivalent to having a 180-core computer devoted full-time to running HTCondor jobs.

The usage of TeideHPC has been of 3,344,042 CPU-hours, which amounts to about 67,000 weekly (about 75% of the limit of 87,500 hours allocated to IAC users).

Finally, for LaPalma we have 3,230,204 CPU-hours, of which 141,083 (about 4.4 %) were used by IAC researchers, and the rest by RES users.

All together, IAC researchers have carried out 5 millions CPU-hours, that is 570 years of computing time, in less than one year.

Python bindings for Supermongo

Supermongo is one of the the most venerable graphics package for Unix, being almost 30 years old. It is still widely used by the astronomical community, and by a number of IAC users who still find Supermongo simple yet powerful. On the other hand, Python is becoming the main astronomical programming language, with a immense array of add-on modules, among which the plotting package matplotlib. Does this mean that you will have to give up SM if you use Python? The answer is NO.

Not many people know that there are some nice Python bindings for Supermongo, which allow you to use the plotting facilities of SM from inside Python, while arrays and variables are managed by numpy. A couple of simple scripts to illustrate this kind of SM usage are provided in /net/nas4/inves2/sieinves/invsoft1/py-supermongo/. If interested, please get in touch with Nicola (an SM fan).

Bleachbit

Exceeding the home quota may have very nasty effects: you can lose your firefox's bookmarks, receive weird errors when launching applications, or even be locked out altogether from your account. Often the culprit are temporary files, such as the browser's cache, files marked as deleted in the file manager, thumbnails, etc., whose location is usually deeply buried in the $HOME file system. To check your home quota, type quota -s.

Bleachbit is a simple tool that helps you get rid of unnecessary files. You can either use the GUI, by just typing (unsetenv LD_LIBRARY_PATH ; bleachbit ) [tcsh] or (unset LD_LIBRARY_PATH ; bleachbit) [bash] (this is needed to work around an issue with GTK in the graphical interface), or take advantage of the command line, for instance bleachbit --preview firefox.cache followed by bleachbit --clean firefox.cache. For usage details, see http://docs.bleachbit.org/. Be careful when using bleachbit: only delete those items you are sure 100% they can be deleted, and disable options you do not understand or not feel safe with.

Agedu

After using bleachbit, you may wish to obtain a global assessment of how much space your data occupy, how old they are, etc. This can be easily achieved by running agedu. A nice explanation of how it works can be found on the agedu main site, or in the Find Out Wasted Disk Space In Linux article. Just to have a quick look at it, first run agedu -s ${HOME}, then agedu -w --auth none and point your browser to the URL shown. So, if you are short of space in your home, despite running bleachbit, give agedu a try to find old, forgotten data that you can delete.

SIE de Investigación y Enseñanza :: N. 56 - November/December 2016 - Contact: