Sunday, April 25, 2021


This post is going to have a drastically different theme than my other posts. I am going to talk about investing money in India. This, however, does not constitute any financial advice. This post just captures and contrasts the result of a particular investment I made a few years ago to another one I could have made instead at that time. So let us begin from the beginning.

After my postdoc at NTU ended in early 2017, I returned to India along with all the money I saved up there. (I think ~NT$100 still remain in the bank at NTU as some interest was deposited after I had left. “Why didn’t I close the account there?”, you ask. That’s because the lady cashier helping me with my international transfers and clearing up my account convinced me that if I decided to come back, I could start using this bank account again, so no need to close it!). These savings were transferred to my NRI account in India. Having returned to India, that account could no longer be called NRI (Non-Resident Indian) so I had to visit the branch and convert the NRI account to an ordinary RI account. The branch manager was fine with doing that but also suggested that I invest most of those savings in a Mutual Fund (MF) instead of just keeping them in the Savings Account (SA) or putting them in a Fixed Deposit (FD). I was thinking of parking these savings in FD, but this guy again convinced me to try this one particular MF, which he said was very much like a FD with almost no risk, and would have some tax benefits. He showed me this demo table to highlight what he was talking about (click on the image to see a high-res version):

FD vs MF Demo

The main takeaway was that after taking into account the Indian taxation rules, the MF would have an effective annualized return rate of 7.1% vs. FD’s 4.9%, even if FD enjoyed 7% pre-tax interest rate. Let’s keep this difference of 2.2% in mind.

One problem was as much as he wanted to say “no risk”, the mutual funds are of course “subject to market risks” so there is no guarantee of returns like there is with deposits in SA or FDs. Another problem was that the money I would put in this MF would be locked for 3.25 years! At that time, I did not yet have an offer from SINP and locking away funds seemed risky from this perspective too. But then everything has an associated risk and the history of these particular types of MF hadn’t seen anything bad so I planned to give it a go. Obviously not with ₹10 Lakhs (≡₹1 Million) as written in the demo table but with half of it.

Yet another problem was that I wouldn’t be “someone in highest tax slab” so was not sure how much tax benefit I would actually get. As has turned out over the years, I am “someone in almost-tax-exempt tax slab” so I think I will get almost no tax benefit from this as can be seen in the table below made in the same format as the demo table (click for hi-res image):

FD vs MF for me

The takeaway from the table above is that the tax benefit for me is none whatsoever. The capital gain after 3.25 years from my ₹500K investment is barely ₹97K, which means the actual effective annualized return rate for this MF is 6.2% compared to 7.1% of the demo table. Adding to that disappointment, an FD created for the same duration with actual pre-tax interest rate of 6.5% would have an effective rate of 7.7% compared to 4.9% of the demo table. So the difference is –1.5% (i.e., an FD would have been a better choice for me than this MF) compared to 2.2% of the demo table.

Anyway, just for completeness sake, let us also look at the actual outcome for someone in the highest tax slab (again, click for hi-res image; the footnotes are same as in the previous table):

FD vs MF for Highest Tax Slab

In this scenario, the tax benefit is there but it is just (6.2-5.4)% = 0.8% compared to 2.2% shown in the demo table.

So the final takeaway is “Mutual Funds are subject to market risks and / or pandemics”. That’s all for this post. I will leave you with

SBI FD Interest Rates

Saturday, March 27, 2021

Holi, Moli, Roli

These are quite important words around this time of the year. The first one refers to the upcoming festival (of colour) ‘Holi’, in which people (mostly sisters) tie threads called ‘Moli’ around other people’s (mostly brothers) wrists, and mix red powder called ‘Roli’ with water to put on foreheads as Tika. There is also the other aspect of Holi, where people play with water and colours and colours mixed in water by drenching and colouring each other. Others, who like to keep some distance from this mess, fill bucket full of balloons with water (with or without colours) and throw them at others from a safe distance. As a kid, I was such a person. The routine for a couple of years during this time of the year was: wake up early in the morning, prepare a bucket full of water balloons (NO colour), go to the roof, and hurl them towards ‘victims’ walking on the roads. As one may expect, the devil is in the details. The (un)fortunate detail was that this house we lived in was basically surrounded by a vast field on three sides, and a wasteland on the other. The roads from where repercussions could not find a way to our house were beyond this field, and those were, obviously, the preferred roads for a kid to assault hapless pedestrians. But it also meant, that kid could never make the balloons land on the roads beyond the field, let alone on pedestrians! So that was how the ‘fun’ aspect of Holi played out for a few years in my childhood. And I feel my daughter is missing out on that. But that’s how it is… times change, people change, circumstances change, priorities change.

Colour Full

Even then, what does not change is the abundance of sweets on this occasion. And I am making sure that at least she experiences that aspect as much or as well as I did. In addition, she did get a toy water-pistol shaped like a dog from her mother yesterday. And she was enjoying it today morning with her menagerie of plastic toy animals. Now, I had never played with a water pistol in my childhood so I thought of joining her too. And she gladly handed the toy-pistol to me. Just after three presses of the trigger by me, the dog-shaped-water-pistol stopped working. If you foreshadowed this happening two sentences ago, kudos to you. I had not and neither had my daughter. But she turned out to be more mature in this situation than I expected. She did ask something like “did it break?”, but without using the pronoun ‘you’. And when I confirmed her assertion, she did not make a big deal out of it. She asked me to fill up the toy with a little more water and continued to tinker with it for a while as I briskly made a beeline towards the kitchen for my breakfast. I am assuming her mother will take care of the rest, or has already taken care of it. Who knows? The moral of the story: times may change, people may change, circumstances may change, priorities may change; but grown-ups screwing up childhoods never changes. And on that note,

Happy Holi

Thursday, February 18, 2021

What Futures Holds?

Those of you who think there’s some problem with grammar above, hold your horses. I am talking about “Nature Futures” column for sci-fi / futuristic stories and I can treat it as a singular noun, it being a name of the column.

So yeah, it’s been a while since I have talked about Futures on this blog. Not because the stories aren’t great any more, but because it is a weekly routine and after a while, one starts taking things for granted. So what’s special about February 2021, you ask!

Well, the latest story. Not really the story itself, but the author’s inspiration behind it or as Nature calls it “The Story Behind the Story”. That small snippet at the end of the story ends with the sentence “After all, people want what they want, and rarely what they need.”. We have all heard some variant of this sentence at least once in our lifetime but this sentence after this particular story struck some chord and here we are typing (or in your case, reading) away a blog post.

It led me to think what I want. My train of thoughts didn’t seem to go very far and my brain didn’t register a valid response. Then I thought about what I need. Again my train of thoughts resisted motion and my brain frowned at the dullness / stillness / motionlessness of it all. Maybe at the end of the day, I want a need. Or, is it the other way around, I need a want. Or there could be a third option and I may have transcended above all and मोक्ष (moksha) should be ready to receive me sometime soon.

Till then, I leave you with my second (ya, only second in a decade!) full-fledged 360° polorama.

2nd 360° Polorama

First 360° Polorama

Sunday, January 10, 2021

A Millenary of Chapters

As 2021 rolled in, the world of manga witnessed the 1000th chapter of One Piece. Yes, you read that right: One Thousandth chapter. More than 2 decades worth of weekly anticipation, sprinkled with nearly 3 years worth of (un)expected breaks by Eiichiro Oda, rolled into 1 giant realization that I’m not going to see the end of this marvellous adventure. But as people say, it’s the journey that counts, not the destination. To those people, I say, hell with you all. Because you have definitely not read One Piece.

Combined cover pages of Chapters 999 & 1000

Anyway, that is all I want to say for now. I feel this year will be big for mangas and we will talk about them once in a while as this year unfurls. Wishing Totan Kobako a complete recovery from his hand injuries and hoping this year finally sees his new work published. Meanwhile, I hope those lovely people who translated Sketchbook in the past can restart scanlating the rest of the chapters covering the last 3½ volumes. If everything else fails, I guess Google Lens will have to do the job. It’s a sad state of the world considering that “real-time translation” was one of the most promising features of the “MS Translator” app on Windows Phone 8/Mobile 10, which never materialized for Japanese in the 5 or so years of the OS’s existence/relevance.

Thursday, December 31, 2020

Poetry… What Does It Mean to Me?

Poetry means something to everyone, ranging from nothing to everything. I fall somewhere in between, depending on the type of poetry. Let me get this off my chest first: Free-verse poetry means nothing to me. If a poem does not even have a single pair of rhyming words in it, then it has no reason to be calling itself a poem. Get it the hell out of my syllabus. Sorry about that, childhood memories came flooding in. But having said that, the last poem of my class X’s Hindi poetry book was a free-verse poem titled “लोहे का स्वाद (Taste of Iron)” by सुदामा पाण्डेय ‘धूमिल’ (Sudaama Paandey ‘Dhoomil’), which is considered to be his last poem. I just couldn’t stop laughing at this poem, every time I read it during the course of that year. It said something so stupid, yet so deep (after our Hindi teacher explained the hidden meaning behind the words) that I just fell in love with the way words could be structured to arouse different emotions in the reader. And to this day, that is the only free-verse poem I (pretend to) understand and (definitely) like maybe because, even though it doesn’t have any rhyme in it, it is short and has a certain rhythm to it. Other free-verses can stop bothering me.

Let me also clarify that I am only talking about Hindi poetry, not English poetry. This is because I’m a theoretical physicist and before I understand any topic, I don’t just need a working example but a working theory to go along with it. In fact, I could do away with the example if the theory is well-worked out in the first place. So how is this related to poetry, one might ask. The relation is till class VIII no one taught us the “theory” of poetry, neither in English grammar nor in Hindi. By “theory” of poetry, I mean answers to questions like, what makes the poems what they are? What are the ingredients that go in them? How are they constructed or structured or conjured? What makes one poem good, others mediocre and the rest bad? I couldn’t bother finding answers to these out myself because I didn’t have such questions then. Why? Because I was not good at languages (partly because we were told that if you are interested in Science or Maths, you don’t have to focus too much on languages; that turned out to be a dum-bass advice as I figured out after all these years when I can’t talk to people without pretending to be an introverted / thoughtful person or without appearing as a tactless / horrible person) so a poem was just another chapter in the book about which certain questions were to be answered in the exams. Oh, and this was also a chapter that needed to be memorized because there would always be a question demanding one to write a poem from memory. (Maybe I will show-off my memory in a future post as I still remember one of those poems from class X.)

However, in class IX & X, things changed when Hindi grammar syllabus introduced us to this “theory” in the form of अलंकार (alankaar) & रस (rasa) or “Figures of Speech” (not “Parts of Speech”) & “Genre / Mood / Emotion” (not sure what the exact linguistic term is in English). They are the ingredients that make poetry what it is. They give the words their beauty, the meanings their depth and the whole enterprise its grandiosity. And even though I can apply this theory to English poems to some extent, it is not the same. There is a certain disconnect because having not got the theory first-hand in school when I was being fed all those English poems without the “theory”, the time to appreciate them has gone. But I am thankful that अलंकार & रस were taught at the last moment and so at least, I can say I get Hindi poetry, in a way I can never get English poetry. I won’t talk about this “theory” here but may in some other future post. But they are definitely the reason I was able to bootstrap myself out of my indifference to poetry and actively seek it out and enjoy it while doing so. That has also led me to a form of poetry called ग़ज़ल (Ghazal) that I love the most because to my theoretical physicist brain it is a format that has so much going on and yet can be described theoretically in a few rules that govern its beginning, rhyming structure, physical structure, and (if the poet feels like it) the end. The simplicity of those rules is just marvellous and the resulting gems have been showcased a lot on this blog along with my English translations, which are not supposed to do the originals any justice whatsoever. These translations are just an attempt to keep some non-Hindi speaking readers on this blog a little longer. So let’s talk about ग़ज़ल.

Colours of 2020!

ग़ज़ल (Ghazal): I will define it in a mathematical way but before we get to it, we need to go through half a dozen other definitions as is usual to understand any well-respected mathematical term like homotopy, homomorphism, homology, check-the-RAM cohomology, Heck Man! Dust-Me-Not Detriment and so on.

Definition. A शेर (sher) is a couplet, i.e., a composition of two lines: S=(L₁;L₂).

Definition. A मतला (matla) is a शेर with both lines ending with the same (set of) word(s): M=(L₁=⋯R;L₂=⋯R).

Definition. रदीफ़ (radif) [refrain] refers to the above-mentioned (set of) repeating word(s): R.

Definition. क़ाफ़िया (qaafiya) refers to the rhyming pattern (not words but the sounds) before the रदीफ़, i.e., L=⋯qR.

Definition. बहर (bahar) refers to the metre of a शेर, or number of syllables in it, or simply put, its “length”: B(S).

Definition. A मक़ता (maqta) is a शेर that contains poet’s तख़ल्लुस (taKhallus) [pen-name]: Mq.

Finally, the definition we were waiting for:

Definition. A ग़ज़ल (ghazal) G is a set of four or more shers, G=[S¹;S²;⋯;Sⁿ] with n≥4, which satisfy the following properties:

1. {S¹,⋯,Sm}∈M with m≥1. (A ghazal must begin with at least one मतला (matla).)

2. {Sm+1,⋯,Sⁿ|L₂=⋯R}. (The second line of rest of the shers must have the same रदीफ़ (radif).)

3. {S¹,⋯,Sⁿ|∀ R, ∃ qR}. (All shers should have the same क़ाफ़िया (kaafiya).)

4. B(S¹)=B(S²)=⋯=B(Sⁿ). (All shers should have the same बहर (bahar).)

5. Sⁿ∈Mq [Optional]. (The last sher may be a मक़ता (maqta).)

Corollary. If n=4, I feel cheated. I mean, come on, just one more! It can’t be that hard to write one more if you’ve already written four shers down, right? Come on!

Theorem. Ghazals are Great.

Proof. Follow the well-known strategy of proof by intimidation. QED□

Example. Let us see the above definition in action for a ghazal that I translated years ago and tried very hard to make the translation a ghazal too. I was reminded of it lately because someone commented on that post! I will obviously not repeat the whole thing here; just a few shers by नवाज़ देवबन्दी (Nawaaz Deobandi) to illustrate the above-mentioned rules.

तुम नज़र से नज़र मिलाते तो
बात करते न मुस्कुराते तो

Tum nazar se nazar milaate to
Baat karte na muskuraate to

Had you looked into my eyes then
Spent not a word, just a smile then

This is obviously the matla of the ghazal with radif being ‘तो (to)’ in Hindi and ‘then’ in English and qaafiya being ‘-आते (-aate)’ in Hindi and the sound of ‘-ile’ in English. Sorry, not really as the first line has ‘eyes’ before ‘then’. As mentioned in my old post, I tried to wedge in ‘beguile’ in the first line to really make the translated sher a matla! Anyway, having decided against that, my translation doesn’t strictly qualify as a ghazal but all the following shers have something that sound like ‘-ile’ in their respective second lines (of course, everything also works in Hindi).

इख्तलाफ़ात होते रहते हैं
आना जाना था आते जाते तो

Ikhtalaafaat hote rahte hain
Aana jaana tha aate jaate to

Differences do pop up once in a while
As in the past, visit once in a while then

दोस्ती में अना नहीं चलती
खुद न आते कभी बुलाते तो

Dosti mein ana nahin chalti
Khud na aate kabhi bulaate to

Arrogance doesn’t go far in friendship
If you refuse to visit, maybe I’ll then

Ah! saved by the ‘I’ll’ which has the sound of ‘-ile’ as one may confirm.

भूलते शौक से हमें लेकिन
भूलने का हुनर बताते तो

Bhoolte shauk se hamein lekin
Bhoolne ka hunar bataate to

Feel free forgetting me but
Teach me this life style then

Again, the sound of ‘-yle’ matches the sound of ‘-ile’ and we are good here too. There are a few more shers in this ghazal for which you’ll have to visit the old post linked above and have to watch the video linked in that post to hear the full ghazal. Well, let me embed the video here just in case you don't want to leave this page:

This ghazal also has a great maqta but somehow I didn’t translate it in my old post; no idea why. Rectifying that mistake here and now, so do enjoy the end of this “comic” ghazal:

बज़्म में दिल-‘नवाज़’ हो जाते
तुम मेरे शेर गुनगुनाते तो

Bazm mein dil-‘Nawaaz’ ho jaate
Tum mere sher gungunaate to

This venue would’ve considered you kind-to-‘Nawaaz’
You should have murmured my shers as a trial then

It is clear this sher is a maqta in Hindi with an exemplary usage of the word ‘दिल-नवाज़ (dil-nawaaz)’ which means ‘kind’ but since the latter half is also the poet’s name, it provides an outstanding example of श्लेष अलंकार (shlesh alankaar) [pun]. However, in my translation I just lazily appended ‘-to-Nawaaz’ to ‘kind’ to make the translated sher a maqta too. In addition, the two lines are just too long so this sher doesn’t have the same bahar as the preceding ones and I also shoe-horned the word ‘trial’ to make up the qaafiya of ‘-ile’. I have to admit none of this imparts any beauty to the translated sher that the original sher has. Anyway, talking about the poet’s pen-name, thinking about the meaning of Nawaaz as ‘cherish / reward’, one may be able to impart some depth to the translation too but that would be very much out of my depth. Hehe... see what I did there? I used ‘depth’ in two places with two different meanings, providing us – as you are well aware – an example of यमक अलंकार (yamak alankaar) [homonym].

And with that, we end this “great” year 2020. I will leave you with another attempt of mine at translating a ghazal into a Ghazal. I feel this one is quite good; you’d agree too,


Saturday, December 26, 2020

माटी री आ काया...

In 2020’s pandemic (as if I’m going to witness more, well who knows?), I was introduced to many new things like working from home w/o knowing when I would start working from office again, taking care of a toddler full-time, joining zoom meetings for anything and everything, learning art online, attending fitness classes online, etc. Among those new things there was also a bhajan written by Muni Roopchandraji. In some of those depressing days of 2020, I and my family have listened to this bhajan in a loop. As the text version of the bhajan is not available anywhere on the internet (or so I think as of now), I thought of writing it down myself:

माटी री आ काया आखिर माटी मैं मिल जावे है
क्यां रो गर्व करे रे मनवा क्यां पर तू इतरावे है
माटी री आ काया आखिर माटी मैं मिल जावे है
क्यां रो गर्व करे रे मनवा क्यां पर तू इतरावे है

जीण तन न मीठा माल खुवा तू निश दिन पाले पोसे है
जीण तन न मीठा माल खुवा तू निश दिन पाले पोसे है
अपणे एक पेट री आग बुझावण कित्ता रा मन रोसे है
अपणे एक पेट री आग बुझावण कित्ता रा मन रोसे है
लेकिन गटका खायोड़ा ने एक दिन भटका आवे है
क्यां रो गर्व करे रे मनवा क्यां पर तू इतरावे है
लेकिन गटका खायोड़ा ने एक दिन भटका आवे है
क्यां रो गर्व करे रे मनवा क्यां पर तू इतरावे है

आ सांसाँरो विश्वास नहीं, कद आती आती रुक जावे
आ सांसाँरो विश्वास नहीं, कद आती आती रुक जावे
जीवन मैं झुकणो नहीं जाण्यो वो जम रे आगे झुक जावे
जीवन मैं झुकणो नहीं जाण्यो वो जम रे आगे झुक जावे
एक कदम तो उठग्यो दूजो कुण जाने उठ पावे है
क्यां रो गर्व करे रे मनवा क्यां पर तू इतरावे है
एक कदम तो उठग्यो दूजो कुण जाने उठ पावे है
क्यां रो गर्व करे रे मनवा क्यां पर तू इतरावे है

ओ तो चार दिनां रो चानणियो सुण फेर अँधेरी रातां है
ओ तो चार दिनां रो चानणियो सुण फेर अँधेरी रातां है
थारी टपरी सारी चूवे है ऐ सावण री बरसातां है
थारी टपरी सारी चूवे है ऐ सावण री बरसातां है
थोडे जीणे रे खातिर क्यूँ भारी पाप कमावे है
क्यां रो गर्व करे रे मनवा क्यां पर तू इतरावे है
थोडे जीणे रे खातिर क्यूँ भारी पाप कमावे है
क्यां रो गर्व करे रे मनवा क्यां पर तू इतरावे है

जो बीत गई सो बात गई अब पाछल खेती कर ले तू
जो बीत गई सो बात गई अब पाछल खेती कर ले तू
मुनि “रूप” कहे सद्गुण मोत्यां स्यूँ खाली झोली भर ले तू
मुनि “रूप” कहे सद्गुण मोत्यां स्यूँ खाली झोली भर ले तू
जो जागे है सो पावे है जो सोवे है पछतावे है
क्यां रो गर्व करे रे मनवा क्यां पर तू इतरावे है
जो जागे है सो पावे है जो सोवे है पछतावे है
क्यां रो गर्व करे रे मनवा क्यां पर तू इतरावे है

माटी री आ काया आखिर माटी मैं मिल जावे है
क्यां रो गर्व करे रे मनवा क्यां पर तू इतरावे है
माटी री आ काया आखिर माटी मैं मिल जावे है
क्यां रो गर्व करे रे मनवा क्यां पर तू इतरावे है

For any feedback/suggestions related to this bhajan, please get in touch with me.

Monday, November 16, 2020

Happy Siegel’s Day!

Today is Warren Siegel’s birthday and as is usual to post private messages publicly on social media (Are blogs considered social media nowadays? Were they ever?):

“Wishing you a pleasant day and a great year ahead.”

Warren Siegel

Reminiscing about past, especially all those semi-physics chats I had with him, I stumbled onto some of his “quotes” that I had saved somewhere secret. And then I thought what better (space)time to air them out than (my blog) on his birthday. Some of his quotes have already appeared here, for example, in “Random Quotes” section of this post.

The first one is about E. Sokatchev, one of the discoverers of ♫ Superspace:

If it is so easy, why give it to a grad student? Why doesn’t he do it by himself? Though I am getting you to do these calculations, so I shouldn’t complain!

I guess the context is pretty clear. The “it” above refers to some (easy?) calculations that Sokatchev assigned to one of his students and “you” is me (obviously). I also had nothing to complain about “those” calculations.

The second quote is about D. Storey, whose work on Feynman supergraphs was relevant to our work (context for the quote on InSpireHEP):

He wrote these two papers in 1982, and then wrote one paper in phenomenology in 1985 and that was the end of him. Hope this is not a prediction.

The prediction refers to the fact that I had barely two papers till then. I haven’t written any phenomenology papers yet but who knows what future holds.

The third quote is a little bit philosophical and I don’t really remember the context. Though, even without context, it is quite relatable and true and a great candidate for inclusion in a list of top 50 quotes by him:

It seems people no longer read others’ papers. They just do their own thing and ignore anything different from their own way of doing things.

The fourth quote is again philosophical and is a great candidate for inclusion in the list of his top 10 quotes:

You know, people forget other people.

Hoping people don’t forget WS for eons to come.

Saturday, November 14, 2020

More Waseem Barelvi

I keep coming back to Dr. Waseem Barelvi because his Shers / Ghazals are just that good. They are inspirational, uplifting and motivational in the best of times and given that the worst of times are upon us now, they mean a hell lot more. Just to keep my spirits high this falumn season, I have ordered a book of Ghazals by him along with two others by (Late) Dr. Rahat Indori and Dr. Bashir Badr. Bashir Badr apparently started writing poems at age seven and I have even heard of an anecdote that his M.A. syllabus included prescribed readings of his own Ghazal(s)! Sadly, I have become aware that he is suffering from dementia now and doesn’t remember even his most famous Shers. These are the three books that I got:

Great Shayari

Waseem Barelvi’s book titled चराग़ (Lamp) is very apt on this day, which is the festival of lights, called by many names in the Indian subcontinent: Diwali, Deepavali, Tihar. So wishing you all “Happy Diwali” and “Prosperous New Year”.

Ironically, all the three books feature some sort of a lamp on the front cover but the other two books’ titles are only vaguely related to it. For example, Rahat Indori’s book is titled नाराज़ (Angry / Annoyed) and maybe the flame of a lamp represents the silent rage of discontented masses. Then there’s Bashir Badr’s book titled मुसाफ़िर (Traveller), which suggests that one might need a flickering light of a lamp to illuminate one’s path. Anyway, more on these books in future posts. For now, we focus on the following Shers:

बातों बातों में जहाँ बात बिगड़ जाती है
फिर बनाओ भी तो वो बात कहाँ आती है

Baaton Baaton mein jahan baat bigad jaati hai
Phir banaao bhi to wo baat kahaan aati hai

When chats devolve amidst chit-chats
Fixing later won’t bring the chats back

हम बताएं तो बताने की जरूरत क्या है
किस को मालूम नहीं आपकी नीयत क्या है

Ham bataaen to bataane ki jaroorat kya hai
Kis ko maloom nahin aapki neeyat kya hai

I can tell but there’s no need to tell
Who isn’t aware of your intentions

अपने बाजार का मेयार संभालो पहले
बाद में पूछना मुझसे मेरी कीमत क्या है

Apne baazaar ka meyaar sambhaalo pahle
Baad mein poochna mujhse meri keemat kya hai

Take care of your shop’s standard first
Only after that ask me what is my price

– वसीम बरेलवी (Waseem Barelvi)

Waseem Bareivi - Mushaira at Riyadh 2018 - YouTube

Wednesday, September 30, 2020

Diabolical Sudoku Solver

Here we are again at another MATLAB program show-off: SuDoKu Solver v11.

SuDoKu Solver v11

Yes, you read that right. A huge quantal jump from the current v7.2 to v11.0 because four new Logics have been added over the last month or so. This allows SS v11 to solve more Sudokus like the ‘diabolical’ ones that appear in newspapers, or generated at the ‘Grandmaster’ level in “MS Sudoku” game, which are only rarely really diabolical. But who is looking at the meaning of that word, anyway?

Those who remember my first detailed post about this MATLAB program will know that 1+3 Logics were ‘my own’ but other 2 ‘advanced’ Logics (Grids and Chains) were borrowed from the exhaustively detailed website on Sudoku strategies: (SW). Continuing that tradition, I have borrowed a lot more this time and implemented them in my own way and bunched them up in 4 more advanced Logics (Scissors, Pincers, Cycles and Nets). That makes a total of 10 Logics and one Smart Brute Force Algorithm leading the way straight to v11.0 and Release 22.

Before I go on to map my ‘Logics’ to SW’s ‘Strategies’, let me talk a little about other important changes. One change that has already appeared in the changelog is the display of recording indicator [] when speech input is on. “Why is this change repeated here again then?”, one might ask. To that non-reader of my posts, I say “Because I am proud of that achievement and this is a show-off post. So get in line with the program and stop interrupting my train of boasts heading full-speed towards the Grandiose Terminal!”. Another significant change that hits visually when SS starts solving a Sudoku is that the various possibilities in cells keep updating as other cells get filled with final answers. It is as if someone forgot to turn off the “Solve Partially” option. It really brings the dynamism of a Sudoku puzzle to the foreground which the visual senses take in to relive its full kaleidoscopic glory. I wish I could write such non-sensical sentences with all the vigour and gusto rivalling those novelists who do it for a living.

Visibility of Possibilities

Talking about solving a sudoku, the nonlinear run over the Logics has also been tweaked to follow SW’s style, up to a point. A major difference is that I still don’t go checking for “Single Possibilities” after every single successful application of a Logic. I check it ‘sneakily’ instead and if no such possibility has arisen, I continue with the same Logic looking for next chain or pincer or net or whatever. Once that is properly done, I go back to the start of the list of Logics (Logic 2 in the table below) and re-iterate till all the Logics are exhausted or the Sudoku is completely solved. Other changes include updated Logic descriptions (including name changes of the Logics), updated colour palette for names of the Logic in the “Comments” box, and some minor code enhancements and cosmetic changes.

Update: I forgot to mention one of the only, really new feature in the program: "Export Solution". Using this menu option, you can export the list of steps that appear on the right as a webpage to compare with other solutions and/or scrutinize the Logics used by the solver. You can see an example in the webpage linked at the end of this post.

Ten Shades of Red

Now let’s enumerate the Logics implemented in v11:

No. Logics in SS v11 Strategies on SW
1 Single Possibilities Hidden Singles [1]
2 Reduction via Intersection Intersection Removal [5,6]
3 Reduction to Multi-sets Hidden Candidates [3,4]
4 Deduction from Multi-sets Naked Candidates [2,4]
5 Deduction from Grids X-Wing [7], Swordfish [10], Jellyfish [16]
6 Deduction from Chains* Simple Colouring [8]
7 Deduction from Scissors Y-Wing [9], XYZ-Wing [11], WXYZ-Wing [21]
8 Deduction from Pincers XY-Chains [14]
9 Deduction from Cycles X-Cycles [12]
10 Deduction from Nets 3d Medusa [15]

*Logic 6 included four rules till v7.2 – two based on “simple colouring” and two on “multi-colouring”. However, it turns out that the two latter rules have been deprecated in favour of six rules of “3d Medusa”. Thus, I have also stripped Logic 6 down to include just the two former rules (and updated their implementation as digging in my decade old code made me realize I had coded only 2 out of 3 cases for one of the rules and 1 out of those 2 cases had a bug so, effectively, I had coded only 1/3 of that rule!) and implemented 3d Medusa in Logic 10 as seen above.

Finally, let’s end this post with some discussion and future outlook as one does in a research paper. One point of discussion is that Logic 9 may be merged with Logic 6 in a future version as both deal with colouring of a single digit. How will that affect the versioning would then become another point of discussion. Second point of discussion could be that the way I have implemented Logic 7 reeks of incompetence, especially given that I pride myself in being a MATLAB programmer. Third point of discussion is whether this program will be ever ported to a uifigure-based app like PG or KC. The short answer is: NOT in the near future. The long answer is: HELL NO! Such an app cannot handle so many “drawnow” commands and unnecessarily slows down the solver (as of R2020b). The speech input via “text()” function had serious issues till now, which have been just fixed in MATLAB R2020b (Very many thanks to the MathWorks support team and engineers who took interest in my ‘bug reports’ and ‘service requests’ regarding this). Though, the implementation is still rough ‘around the edges’ leading to the feeling of overall ‘slowness’ of the app GUI. So ya, I won’t port SS (and even AB because of the heavy usage of GUILT) to uifigure-based app for the foreseeable future.

The last point of discussion is what more can one expect in terms of additions to the list of Logics in SS. The short answer is: NOT much. The long answer is: I don’t think I will ever try to implement “Extreme” strategies of SW so let’s only consider the list till “Diabolical” strategies totalling 22 strategies. I am not interested in the strategies related to uniqueness so four strategies numbered [13, 17, 19 & 20] (numbers as of writing this post) can be safely ignored. That leaves only two strategies out of the 22 that I have not included in SS yet: SK Loops [18] and APE [22]. Not sure about the former but the latter has been on my mind since more than a decade as one can verify from the end of my previous post. So over the course of next couple or so years, we may see one major version upgrade: SS v12. Till then, have a go at

SUDOKU SOLVER 11.0.σ Release 22

Wednesday, August 26, 2020

Happy Witten’s Day!

My calendar says it is Witten’s birthday today. Hence this post’s title.

Many people have heard of Schrödinger’s cat but how many people have heard of Witten’s dog?

Thought Experiment

Most people follow Newton’s laws of motion but how many can truly say they understand the Newton-Witten equation?

Most people have no idea where this is going but then neither do I. Though, I do hope he does not remember the day almost a decade ago when I was able to “offend” him in a short walk to Stony Brook train station by suggesting he should have done something else or gone to some other place or some such thing. I also do not want to remember such “offensive” things for obvious reasons. However, I do remember that I was going for a haircut on that day and today I realize I need, very urgently, another haircut. But then it is raining heavily today and tomorrow is another day of lockdown here. So better to postpone this trip to the barber shop till next month.

With this existential crisis out of the way, let me read one of his papers today on the occasion of Witten’s Day. (I guess that is how one celebrates (t)his day!) Hmm… interesting! Let’s make it two as I choose the following papers (taking up less than 20 pages):

2004.14192 & 2005.12336

Sunday, August 16, 2020

Post-20 World…

What would the post 2020 world look like? One might wonder at this point in time… But who knows? I mean, who really knows? Really, who at all?


Anyway, that’s not what the title of this post refers to. It refers to the fact that I crossed the 20 papers mark this month, last month, this year depending on how you count. But let’s keep it simple and count the entries on InspireHEP (20), subtract my thesis (-1) and add two papers from IITKGP that are not there (2) so we get a total of 21. And that’s definitely crossing the just-made-up-number-for-this-post of 20 last month.

Now one may be wondering: Am I proud of this “achievement”? Not really, but I am “proud” of the last few papers I’ve written. That sentence may sound like I’m suggesting am not proud of some papers written before those. Precisely, that’s what it rightly suggests as I’m indeed not proud of a couple of those papers. But that’s a story for another day, when I don’t have much better things to do than to reminisce about things that didn’t exceed my expectations.

Of course, no scientific activity is done in vacuum (in a metaphorical sense, I guess), it is a result of collaboration, knowingly or unknowingly. And talking of collaborations, I seem to have had only two long-time collaborators: Warren Siegel and Marcos Crichigno. Former for obvious reason and latter also for obvious reasons. On last count, I have 6 papers with both (no overlap). With every other collaborator (of whom there are many, which surprises me!) I have only a single paper (tons of overlap). That may change in near future but I like the numerology as of now.

Another interesting fact, one of my last year’s paper’s list of authors abbreviates to AB²J²M! For the unfamiliar ones, ABJM is another well-known (to those who know-it-well) abbreviation for authors of this paper: O. Aharony, O. Bergman, D. L. Jafferis, J. Maldacena. The ABJM theory is like a harmonic oscillator for 3d supersymmetric theories, just like N=4 super Yang-Mills is for 4d ones.

Talking about my papers, how can I not talk about my parody papers from yesteryears? These are the two: 2010 and 2014. You might find that the latter has some overlap with my newest paper, which is purely coincidental. (Ya, right!) I guess I’ll leave it at that for now with the interesting facts about my publication record.

Oh, you might have noticed that my site has got a new coat of paint. That’s because Google is transitioning people from the old Sites to new Sites so I had to do the transformation sooner or later. I think it looks all right and it displays nicely on all sorts of devices. But gone are the days when one could edit the HTML code directly. That’s why the font colour is just black and blue on the pages on this new site!

To finish this post, I will leave you with one Sher from the last Ghazal of Rahat Indori who passed away on 11 August:

वबा ने काश हमें भी बुला लिया होता
तो हम पे मौत का एहसान भी नहीं होता

Waba ne kaash hamein bhi bula liya hota
To ham pe maut ka ehsaan bhi nahin hota

How I wish the epidemic had claimed me
Death would not have then indebted me

राहत इंदौरी (Rahat Indori)