Another pair of Concerts

This time it was the Hyderabad brothers and Sri Sangeetha Kalanidhi N. Ramani.

The Hyderabad brothers were simply amazing! The accompaniments were very good as well. They started off with the nATTaikurinji varNam. Dasharathi in tODi was amazing and it was followed by a rather-funny sounding fast song in some rAga which I found similar to senjuruTi and taraNgiNI, and then an RTP in latANgI.

To walk into the Woodlands Hotel Auditorium (Valayapatti Kaashyapa Naadhalaya) after listening to a concert in the Music Academy TTK hall was horrible. The acoustics of a banquet hall are completely unsuitable for a concert. The reverb was simply too much. In addition to that, the flute was given excess volume, IMO. Me and Prasanna were kind-of turned off… we went out for sometime and then got back in, this time choosing a seat as far away from the speakers as possible. Minus the horrible acoustics, everything else was par excellence. The main piece was a familiar krti in tODi (Don’t know the sAhityam). I was unable to “understand” the taniyAvartanam – the acoustics added to this. Somehow, the same hall was less worse (but still, bad) for MSG’s concert yesterday – maybe it was the volume. Sri Ramani ended with popular songs like Ennathapam in kApi, tIrAdaviLayATTu (rAgamAlikai) and the film hit kARRiniley varum – all sounded amazing on the flute. He also played the popular tillAna in bEhAg composed by lAlguDi jayarAman. The other song I had heard before amongst those he played was gajAnanAyutam gaNESwaram in cakravAkam. There was also a krti in kAnaDa and one in mOhanam.

Concert season in Chennai

I decided to come back to Chennai for a span of about 48 hours, to finish some fee payment at IIT, as well as to listen to concerts, which occur at almost every available auditorium in Chennai between 25th December and 30th December.

My friend Prasanna, who is like my “Guide” and Encyclopedia for Carnatic Music had already planned the concert schedule for the day. So we met at about 3:45 PM opposite the Music Academy, under the flyover, and after a brief “lunch” at Woodlands Hotel, sat for Sri Sangeeta Kalanidhi M.S. Gopalakrishnan’s concert at the auditorium in Woodlands Hotel (Valayapatti Sabha)

For the Carnatic newbie who had never heard any of the “Gods” live before that I am, Sri MSG and Smt. Narmada (daughter) were simply stunning on the Violin. They started off with Nattiakurinji Varnam. It was simply stunning IMO. The main piece was in tODi, and somehow I wasn’t able to appreciate that, considering my n00bishness. They also performed a wonderful rAgamAlikai based on Hindustani Ragas (Desh, Darbari Kanada, Behag, Bhimpalasi). I really enjoyed this concert.

Then, after a brief snack at the Music Academy canteen, we went to Sri Sangeeta Kalanidhi T.N. Sheshagopalan’s concert. He was accompanied by Sri Guruvayoor Dorai on the Mrdangam and Sri Sangeeta Kalanidhi M. Chandrashekaran on the Violin, apart from Ghatam, Tambura and Vocal accompaniments. Sri TNS was simply amazing, except for his lack of hold of the swaras – which must be attributed to his old age. (He also went totally off-rAga once). For the first time, I heard and “understood” a “Shrutibhedam” or “Grahabhedam”. Sri TNS performed Chakkaniraja in Kharaharapriya and RTP in hamsAnandI. The RTP was simply stunning. Almost nobody understood the mathematics of his kOrvai – it was so complicated! Sri M. Chandrashekaran, Sri Guruvayoor Dorai and the Ghatam artist were amazing as well.

Enjoyed it thoroughly. Looking forward to a similar experience tomorrow, with N. Ramani on the flute and the Hyderabad Brothers.

Asteroid-magnitude fix for KStars

I submitted a patch today on the mailing list, to fix magnitudes of asteroids. It was a trivial patch, but involved quite some research to learn the correct formula.

I was trying to find out how I would use the “orbital” elements H (Abs. Magnitude) and G (Slope Parameter) to find the magnitude of a asteroid / comet. After many many futile attempts, Google finally put me at Seichii Yoshida’s (the well known comet researcher) website:

http://www.aerith.net/astro/Encke-nucleus.html

It didn’t take me long to get KStars to use that formula. Now, there’s some agreement between KStars and SB What’s Observable. Vesta was good with KStars showing 7.9 and SBWObs showing 7.97
but I wasn’t so happy with Ceres (KStars = 8.3, SBWObs = 7.95) – but it is far better than the case earlier, which was setting the magnitude to H!!!!

The patch is available here. Ignore the extension and open it with any text editor.

Mail Merge

I remember long back, during school, we had to learn this thing called ‘Mail merge’ in Wordstar or something like that. (I remember mugging those wordstar shortcut keys like C-k b, C-k k to mark blocks and crazy stuff like that) I felt it was a great thing to be able to mass mail people and still make it sound very friendly:

Dear Mr. <n00b-who-got-fooled-by-mailmerge>

I was in a similar situation when I needed to send out BAS Web-Privy Members’ accounts (like http://members.bas.org.in/kstar for instance). So this is what I did – I had the members’ names, ftp logins, passwords blah blah blah and their email address in a ‘:’ separated list in a file, where I saved the details as and when I created the accounts. Then, I typed some e-mail format that went like

Dear NAME,

Your account has been created, your login name is FTPAC and password is FTPPASS

b lah blah blah

Then, I wrote this tiny, ugly bash script that did it. It’s highly inefficient and I’d love to hear ways to do this more efficiently. Here it is. Basically uses awk on each line of the file listing the account details (‘webmem’ as I’ve called it) to retrieve the info into variables and then uses sed on the email format to replace all those “NAME” and “FTPAC” stuff by their corresponding values. Finally, pipes it into mail to send it to the account holder.

The power of a GNU-empowered terminal

My father needed some help. The task at hand was to send invitation SMSes to about 200 mobile phone numbers.

The mobile numbers were in a text file like an address book with several irrelevant fields. The mobile numbers were stored in the form of ‘Mobile:<number>\n’ . We wanted only the mobile numbers, so I did a

cat <phonebookfile> | grep Mobile

and there – all the phone numbers were separated. Next, I wanted to throw away the Mobile: part and retain only the number. That was done using awk:

cat <phonebookfile> | grep Mobile | awk “BEGIN{ FS = ‘:’ } { print $2 } > listofnumbers

Next, we wanted to send an SMS to each of these numbers. I typed the SMS into some file (call it smsfile) and then connected my mobile phone to the computer and then did a

for i in `cat listofnumbers`; do cat smsfile | gnokii –sendsms $i >> gnokii-out 2>> gnokii-error; echo $i >> finishednos; done;

And that’s it! We had some trouble inbetween, and sending failed starting from the Nth number in the file. So what we repeated the command with tail -n <num> instead of cat on listofnumbers, to send it to the remaining.

That’s the power of BASH + GNU on the command line.

DBus Example Code

I’m trying to learn to use DBus GLib API in C and found it difficult to get good documentation or a tutorial easily. The D-Bus Tutorial will help you write the simplest possible DBus program and then leaves you! Atleast, so I felt. So here’s some code that I wrote to illustrate subscribing to remote signals using DBus. I’m a newbie programmer, so please suggest better code and help me!

You can find the code here: Signals with DBus.

Sorry for the inconvenience of having it as .odt – wordpress doesn’t allow extensions like .txt or .cpp. However the file doesn’t have any formatting and you can just open it with any text editor, or mv it to a .cpp

Using procmail to remote-control your comp

My computer at IITM is jailed onto the local network due to NAT, Proxy server etc.

Thus, my computer back there has access to internet, but the internet doesn’t have access to it. So, how do I run commands on it remotely? Here’s a simplified crappy version that works to do this.

My system is on almost all the time and connected to the IITM intranet. It keeps downloading my mail from a mail server (that is accessible both from the intranet and the internet) using a cronjob running getmail and passes all received mail to procmail. If your setup uses procmail to filter mail and it is invoked through a cronjob (or by a daemon or something), you could get procmail to execute command lists from your e-mail. In .procmailrc, you’d add something like this:

    # —– STARTS HERE —–
:0 fbHB
^<some test cases to identify if the email is a command list>
| bash # I do something better than this, but the code is dirty.Will post after improvisation.
/dev/null
# —– ENDS HERE —–

Of course, there’s a lot more scope for improvisation, like verifying PGP signature to ensure that the message is really from somebody who’s authorized to control the computer.