Saturday, January 18, 2014

Jan-1 2011 - New year wishes

(collecting from FB)

Still Relevant:
Wishes for the new decade: May your options never suffer time decay, may 400 Cr scams erroneously park funds in your account, may your company HR realize that money is the biggest motivator, may your cell battery last through all important business hours, may you never fall sick on a weekend, may your increments beat food inflation, may you find one politician you can admire without being embarrassed.. Cheers!!!

DND - Complain today for a peaceful tomorrow

For ppl on Vodafone (and possibly other networks as well) and registered for DND/DNC - Simple way to lodge a complaint:

SMS to 1909 with the following:

<details of the issue - spam call/SMS, nature of call> , call/sms from <Phone No> at <HH:MM>, <DD/MM/YY>
e.g.: 
SMS to 1909: Message text -
Spam call offering astrology services, CALL from +91xxxxxxxxxx at 17:50, 12/01/14
Note the two Commas, do not add any other comma in the message body.
Extremely easy to lodge a compl if your phone supports templates and quick response. Have had good successs with the service, with multiple land-lines being permanently disconnected.

Dynastic curse on India

(collecting from FB)

Quite frankly, if you outlaw dynastic traditions, including a limit on inheritance, you will curb the major chunk of corruption.
Family and progeny's welfare - "I am doing this for their welfare/future" - is how everyone justifies their acts in their minds (leaving aside the petty corruption fostered by a combination of poor pay, poor recruitment, poor resource availability and cumbersome process).

Put simply:

(1) Put restrictions on having any blood/close relative in the same organization for a set number of generations (to prevent cross marriages). With the recent changes in Company Law, shell companies/cross holdings and complicated investment routes for front companies, should also be curbed to some extent.
(2) Limit the inheritance value to social security levels - provide for subsistence but not for opulence - Force everyone to be masters of their own destiny, and not depend on hand-outs.
(3) Put limits on number of consecutive terms - if 2, 4-year terms is good enough for US president, it better be good enough for everything else. With the Indian population, you will never have a shortage of key skill-sets.

Obviously, none of it will work without universal compulsory education and free access to information (internet, etc) 'coz quite frankly, "Gyaan hi aapko aapka hak dilata hai" [my effort to lighten an inordinately heavy post]

Bad stats in hallowed halls

(collecting from FB)

First/ Early impressions on Raguram Rajan - Enviable background and Awesome experience but confusing policy signals and *definitely* not a statistician:

Very surprised that he allowed such a flawed index to be published, could be political compulsions as he definitely does not appear to be that naive.

Full report here: www.finmin.nic.in/reports/Report_CompDevState.pdf
and
http://www.scribd.com/doc/171140093/Raghuram-Rajan-Panel-Report

- http://blogs.economictimes.indiatimes.com/policypuzzles/entry/raghuram-rajan-committee-report-on-states-least-developed

AND

http://www.firstpost.com/economy/put-it-in-the-dustbin-raghuram-rajans-report-on-states-seriously-flawed-1137647.html
feeling annoyed.

Farming Reforms - the lack of it (more precisely)

(collecting from FB)

Agriculture and allied sectors account for 50% of the workforce / population of India. How do you "control" such a big vote bank? Definitely not by allowing improvements in the quality of life... The traditional method has been to invest as little as possible into warehousing facilities which puts the farmer in a very pitiful situation, given a choice between cartelized / license-Raj afflicted APMC and rotting produce. The middlemen squeeze both ends of the supply chain and provide the political masters with the swelling coffers of the always welcome funds.

Little surprise that Mafia/Thugs/Builders/Middlemen are so closely associated with politics.


No bed of roses: Sachin Shewale, a farmer in Nashik, was forced to sell his produce at a low price to the traders' cartel, as he did not have proper storage facility. Photo by Janak Bhat

Managing 'talented' talent!

(collecting from FB)

Relative Grading: Was reading someone's opinion on what went wrong with Obamacare website (link 2) which led me to the more generic problem that plagues corporate world - How to review 'good' people and what happens when you don't do it right? (Link 1)

Link 3 is a generic good read on how corporate bureaucracy kills the best talent, specifically how MS went from a $600 Billion company in 2000 to $300B today (Link 4 - Apple went from $5B to $600B in 2012 and $460B today)
from: http://blogs.wsj.com/marketbeat/2011/10/06/apple-market-cap-vs-exxon-microsoft-and-ibm-1981-2011/

Vote for Change

(Collecting from FB)

Have you checked the voter registration list?

It's not just the people who vote which decides elections, to a large (larger?) extent it's the people who don't - different demographic /ethnic /social segments have different propensities for turning up at the election booth.

Read this report in context of the last three census reports to understand the direction and reason of vote flow : http://samaj.revues.org/2787

Time for compulsory/ e-voting? Argentina, Australia and Brazil already follow the compulsory voting principle. http://www.theguardian.com/politics/2005/jul/04/voterapathy.uk

eBay Guarantee is Worth Nothing (or very little)!

(collecting some thoughts from FB - eBay  India deleted some critical comments so it makes sense to preserve these for posterity):

On receiving a defective product from eBay, I raised the issue on their facebook wall. First, they directed me to their webapp which appears to the public as a resolution being provided but is nothing more than a mechanism where you can submit a query. Obviously they gave a poor answer again, so I decided to shame them - I pasted their response back on the wall so that everyone could see the query and results. 

eBay's response: they simply deleted all comments and disabled my write access!!

Mine does not seem to be an exceptional case, it seems to be the normal practice from eBay India as there were other critical comments that they have deleted as well.

This is what I had posted as a response to someone who had mentioned that eBay Guarantee is a great thing in a thread:

Don't buy any expensive stuff from eBay, most items are actually not covered under the eBay Guarantee. When You complain and post on their page, they will post a link for resolution.

Just so people know what happens when @ebaydotin posts links asking people to go there for quick resolution, copy pasting from what I actually got there. A) they provide no resolution and B) they are quite unapologetic about unethical business practice of misleading people with eBay Guarantee logo for products they do not intend to Guarantee:

Me: Why do you show eBay Guarantee while buying products for which you have no intention of honouring the same? Also, a 2800 word T&C with a 10 word clause for exclusion of manufacturer warranty may be legally correct, but is an unethical business practice. People should know about this behaviour.

13, Jan 2014

EBay-Unethical-Stuck-Tape:Dear Rahul, We would like to inform you that your claim has been denied as your item was under manufacture warranty and according to our eBay guarantee program we exclude item with manufacture warranty.

Also we would like to inform you that our system is designed in such a way that in every listing you will find eBay guarantee logo.

We would request you to kindly visit the service center and resolve your issue or else you can contact your seller and resolve your issue amicably. Thank you.

The Power of Zero

(Update: A few members have asked me to make this less 'random', more to the point and more readable)

-----------------------------------------
The Power of Zero OR 
To get somewhere, remember where you came from OR 
Bad Math and Bad Rebuttals
-----------------------------------------

I recently received a few links ([1], [2], [3], [4]) which show some 'brain-melting maths' to prove that the infinite series represented by S = 1 + 2 + 3 + 4 + 5 + ... is equal to a small negative fraction (-
112 to be specific). I am sure that the brain melting preceded the maths rather than the other way around, else this would not have seen the light of day, let alone so many posts.

On the face of it, the proof looks to be quite smart, which explains why it is showing up in so many places. Plus, the honorific attached to the authors was that of Professors, so very few people actually challenged it.

The rebuttal [5] missed the point as well.

First a summary:

The 'proof' uses the Cesaro summation of the Grandi's series as the foundation (*NOTHING* wrong with this, in the context).
Reusing the text from the 'Bad Rebuttal' which actually provides a good summary:
============= Begin Ctrl-c-Ctrl-v ====================
We'll consider three infinite series:

S1 = 1 - 1 + 1 - 1 + 1 - 1 + ...
S2 = 1 - 2 + 3 - 4 + 5 - 6 + ...
S3 = 1 + 2 + 3 + 4 + 5 + 6 + ...

S1 is something called Grandi's series. According to the video, taken to infinity, Grandi's series alternates between 0 and 1. So to get a value for the full series, you can just take the average - so we'll say that S1
12. <snip>

Now, consider S2. We're going to add S2 to itself. When we write it, we'll do a bit of offset:

S2          : 1 - 2 + 3 - 4 + 5 - 6 + ...
+ S2      :      1 - 2 + 3 - 4 + 5 + ...
====   : ===============================
2 * S2     : 1 - 1 + 1 - 1 + 1 - 1 + ...

So 2 * S2 = S1; therefore S2 =
S12= 14.

Now, let's look at what happens if we take the S3, and subtract S2 from it:

S3           :    1 + 2 + 3 + 4 + 5 + 6 + ...
- S2         : - [1 - 2  + 3 - 4  + 5  - 6 + ...]
===== : ===============================
S3 - S2    :    0 + 4 + 0 + 8 + 0 + 12 + ...
or
S3 - S2     : = 4(1 + 2 + 3 + ...) = 4 * S3 and therefore -S2 = 3 * S3 and S3 = -
112.

======== End Ctrl-c-Ctrl-v and Bad-Maths ==========

Good Maths - The actual rebuttal, etc:

First, there is nothing wrong with assigning the Cesaro summation of
12 to Grandi's series, as long as you know 'where you came from'.

Understand it this way, if a car starts at rest, and then accelerates at a constant rate to hit 1 mile per hour (a rather safe driver) in exactly one hour, and then decelerates at the same constant rate in the next hour, his speed at the hour mark would be 1, then 0, then 1 again and so on. This is what you expect at the end of each term in the Grandi series (n1:1, n2:1-1=0, n3:1-1+1=1, and so on). By following the above approach, the car would have covered
12 mile in the first hour, and another 12 mile in the second. If the driver continues in the same fastidious vein till gas stocks last, he would have done an 'average' of 12 mile per hour over the course of the adventure. You can also think of this as the area under the line graph that keeps going from 0 to 1 and then back to 0 after each unit on the x-axis. Phil Plait uses a similar Stairways to Heaven analogy in link [4] - look at that graph for reference or the first graph on the Google Spreadsheet [6] [http://goo.gl/jtbZi2]. 
 S2 derivation is also correct as the average converges to 14:

Now that we have the Cesaro sums out of the way, we are ready to identify the fallacy - remember the power of the zero!
In fact, the original proof is correct up to this point:
S3 - S2: 0 + 4 + 0 + 8 + 0 + 12 + ...

The failure is in the next step where the right hand side is equated to 4 times S3. The power of zero resides in the fact that you cannot ignore it. Remember, the car analogy up top? If the car runs at a constant speed for an hour, it *seriously* impacts the averages, and it does not actually start running 4 times faster if it does a 4x speed only the other hour. Fact is, the right hand side of the equation is actually marginally less than S3. It would be closer to state that S3 - S2 = ~S3 (approximately S3) or almost S3 if our driver broke all laws of physics (and the speed of light barrier) and followed the speed-acceleration requirement of the higher terms in our series. Look at the graph 3 in [6], Average of (S3 - S2) (red line) is marginally lower than Average of S3 (orange line).
Graph 4 compares S3 (Green line) and (S3 - S2) (Blue line), you can see how S3 manages a slender lead while the Blue line zigs-zags around it.:
The 'trick' or mistake lies in forgetting 'where we came from' - Cesaro sum makes sense for the series, if and only if you are looking at the 'averaging approximations'. Once you start doing mathematical operations with infinity, the vortex opens and sucks your melted brain into the parallel universe.
However, if forced to approach the Cesaro sums with arithmetics, do note that by the very nature of partial sums, the order of the series and the presence of zeroes may make a huge difference to the partial sums. Also, deductions on series where the 'average' is a divergent function, require special care and caution. Focusing on the differential of the the function should make arithmetic more intuitive and also allow one to appreciate the impact of zero slope.
So long, and thank you for the fish, er your time, for reading this. Hope you learnt something about the dependability of whole numbers - their sum does NOT become negative, however you may twist it - AND any 'Physics application' of this 'property', as claimed by the Wikipedia article [7], needs a serious peer review.
I think Ramanujan was pranking Dr Hardy in 1913 with this.

Cheers,
Rahul Raj
Not-a-mathematician-in-spite-of-my-teachers'-best-efforts

Links:

Bad Maths:
[1] Authors' site - 'Original' source : http://www.numberphile.com/videos/analytical_continuation1.html
[2] On YouTube - Same source: http://www.youtube.com/watch?v=w-I6XTVZXww#t=22
[3] Authors' blog where they defend the same : http://periodicvideos.blogspot.co.uk/2014/01/thanks.html
[4] Bad Astronomer - Phil Plait not understanding the less celestial numbers/ the FB link I received through multiple sources: http://www.slate.com/blogs/bad_astronomy/2014/01/17/infinite_series_when_the_sum_of_all_positive_integers_is_a_small_negative.html

Bad Rebuttal:
[5] Someone who 'misses' the point : http://scientopia.org/blogs/goodmath/2014/01/17/bad-math-from-the-bad-astronomer/

Almost Good Maths:
[6] Calculations for the Cesaro sum - Google Docs link: http://goo.gl/jtbZi2

Wiki:
[7] http://en.wikipedia.org/wiki/1_%2B_2_%2B_3_%2B_4_%2B_⋯