If your computation is dominated by exponential function evaluations, then it makes a significant difference whether you evaluate the exponential function exp() in single precision or in double precision. You can reduce your computing time by roughly 25% when moving from double precision (double)…
youtube-dl is a set of Python scripts for downloading videos from YouTube, Twitter, Vimeo, and many other sites, see for example the list of supported sites. This is a handy tool if you want to watch videos or listen to music on your smartphone: Download them with youtube-dl and store them on your…
In SQL Datamodel For J-Pilot I described the SQLite datamodel. I wrote a J-Pilot plugin which can export the below entities and write them to an SQLite database file. The direction is one-way: from J-Pilot to SQLite.
Address
Datebook
Memo
To-Do
Expense
Various categories for above entities
Adding…
Currently J-Pilot stores its data in binary form which is compatible with the original Palm data format. See Palm File Format Specification. Reading these binary formats is not simple, see for example pdbrd.c. Portion of the internal structure looks something like this:
typedef struct { //…
Sharing your terminal input and output can be done in different ways.
kibitz, see Linux commands: expect and kibitz
VNC
Skype / Teams / Zoom, etc.
tmux
1. tmux essentials. tmux (tmux wiki) uses the following vocabulary and hierarchy.
server
session-group
session
client
window
pane
The…
Keeping J-Pilot data in sync with Android smartphone is quite a challenge. See my post about Google calendar. Copying contact data from J-Pilot to Android in the past went like this:
Export data from J-Pilot in vCard (vcf) format
If required, fiddle with this vcf file with some Perl…
I used SSHelper for some time to rsync my files from my Linux machine to Android phones, see here. I most notably used this for transfering photos. I now use Termux. I prefer Termux over SSHelper as it allows to install new programs within Termux using pkg or apt-get.
Starting Termux looks like…
Adding 30 Cents to my monthly bills bought me Gigabit internet access. I now pay 39.99 EUR per month. Previously I had 100 MBit/s. From user's experience I do not feel any significant difference. Of course, for all my mobile devices, like smartphones, laptop, there is and will be no difference as…
Vodafone router does not allow to turn off firewall permanently. It will insist on switching it on after 24 hours.
Version of this router in question:
Firmware version: 01.02.037.03.12.EURO.SIP
Productname: Vodafone Docsis 3.1
This "Made in China" router using…
This blog was viewed more than 100.000 times since its inception and had more than 76.750 visitors. The averages per month are:
As numbers:
The most popular posts over one year are:
The most popular posts over all years are:
Distribution of countries accessing this blog over last 365 days, USA…
Looking at my account page in GPUGrid I notice that my computations have lead to some publications. Nice.
Task
Papers
Topic
3063rd/3113
Giorgino et al, J. Chem. Theory Comput, 2012
cancer
3389th/5798
Sadiq et al, PNAS 2012
hiv
1801st/1995
Venken et al, JCTC 2013
hiv
1886th/3349
Buch et…
I am running fail2ban since November 2017 and all unsuccessful attempts to log-in to sshd are monitored.
Breaking down these attempts according country shows that Chinese IP addresses are coming first here.
The numbers are:
27639 China
13589 United States
8641 France
3985 India
3418 …
Recently one node was changed from octacore to hexacore. Since that time sinfo showed this node in STATE drain. Stopping and restarting slurmctld did not resolve the issue. Log file /var/log/slurm-llnl/slurmctld.log showed
[2019-12-31T23:57:52.588] error: Node X appears to have a different…
When using bitmap indexes in Oracle database one must watch out for deadlocks, see for example Tom Kyte's remark on Bitmap indexes and locking. This is by design of bitmap indexes. Below example is given in Oracle Bitmap Indexes Limitations/Restrictions.
Problem occurs on "Oracle Database 12c…
Dynu is a free dynamic DNS service. As described in Microsoft Brought Down No-IP.org I have to cope with big business just pushing their own interest and not caring on small business or private customers.
I tried to update IP address for Dynu using ddclient using package ddclient. This failed. The…
This blog was viewed more than 90.000 times since its inception and had more than 68.630 visitors. The averages per month are:
The most popular posts over one year are:
The most popular posts over all years are:
USA is at the top of viewers of my blog this year, as before:
Google Chrome on Android version 74.0.3729 can no longer clear history, cookies, local data, etc. See screenshot below.
Even when this process is running completely uninterrupted, nothing happens. I.e., changing display sleep time to 30 minutes, Google Chrome will not finish.
Problem solution:…
If one needs to know when some website has been visited in Mozilla Firefox then go to the default directory and open the places.sqlite file:
cd ~/.mozilla/firefox/<xyz>.default/
sqlite3 places.sqlite
Issue below SQL command
select visit_date,
datetime(visit_date/1000000,…
On 04-Mar-2019 I shortly experienced a downtime of my two blogs here on WordPress.com. Just a few minutes. Because this is so rare I made a screenshot of this event. See below.
Below two blogs were affected:
Elmar Klausmeier's Weblog
Collected Links
I encountered the following error, when I wanted to connect to Oracle v12.2.0.1.0 database with Java 1.8.0_192-b26:
java.sql.SQLRecoverableException: IO Error: Connection reset by peer, Authentication lapse 321631 ms.
This was unexpected as the same program did run absolutely fine on another Linux…