For a second there I thought you said '14 lakhs'

From The Hindu:

Mohandas Karamchand Gandhi’s iconic Dandi March in 1930 to protest against the British salt tax has inspired pen-makers Mont Blanc to come out with a limited-series pen on the Father of the Nation.

The high-end pen is priced around Rs.14 lakh, according to a watch retailer.

The pen comes with a gold wire entwined by hand around the middle, which "evokes the roughly wound yarn on the spindle with which Gandhi spun everyday."

You can't make stuff up like this even if you tried: using somebody whose life was the epitome of simplicity to sell a fricking designer pen that costs Rs. 14 lakh.

There's a bright side to this, though: all we have to do is hook up some magnets and coils of copper wire to Gandhi's mortal remains in Raj Ghat, and voila, an instant solution to our perennial power shortages.

Somebody please take the keyboard away from him

At this rate, he's not going to last long in politics. I think it's time the writer in him is locked up in a closet, at least as long as he's a minister. Here's an idea: whenever the urge to tweet seems to become overwhelming, summon one of your minions in the ministry and bawl him out -- this will have the added benefit of bringing in some discipline as well.

By the way, studies have shown that cutting down your twittering by even as little as five tweets a day can allow one to fit in an average of 1.2 extra engagements in an already 'ridiculously full' day.

Question

If The Lost Symbol is so hot, why am I being spammed with so many emails offering the book at big discounts, including exclusive offers from my credit card company (yeah, exclusive as in "only for our two million cardholders")?

Indiaplaza even went so far as to send an email masquerading as a review of the book, with the reviewer practically wetting themselves in their praise. Wait, I think I was too harsh -- reading the review more closely, it looks like a really different plot this time: last time it was a French scholar who requests a meeting with Langdon and dies before the meeting could take place, leaving behind a tantalizing clue, while this time it's an American professor who pulls more or less the same shit. My bad.

Update:The Onion chips in:

Most chillingly, many agreed, is that while Michael Crichton's death has been a positive step, Dan Brown remains very much alive.

World Bank approves $4.3 billions in loan to India

Nothing particularly significant in this, except what a portion of the loan is meant for: to shore up the capital of some of the state-run banks. Two questions: 1) What is the need for a loan from the World Bank for this insignificant -- relatively speaking -- amount when we have something like $258 billion dollars of foreign exchange reserves? 2) Do these loans come attached with any conditions related to deregulation or 'financial innovation' that these banks must agree to?

The hydrogen bomb controversy

Today's Hindu carries an article about the controversy generated by Santhanam, in which M K Narayanan defends the government's position about the success of the thermonuclear test. Unfortunately, nearly all the points are pretty much untenable (unless he said something more, and it was not published). Samples:

The thermonuclear device had a yield of 45 kilotons. I have chosen my words carefully — 45 kilotons and nobody, including Mr. Santhanam who has absolutely no idea what he is talking about, can contest what is proven fact by the data which is there

I find it hard to believe that the DRDO project lead in charge of the whole thing (i.e. Santhanam) doesn't have a clue what he's talking about.

Asked about the doubt the former Army Chief, V.P. Malik, had raised about the efficacy of the hydrogen bomb, he said: “I think the person to answer that, is the present chief and not the past chief…”

Just because someone has retired from his post, he doesn't lose whatever credentials he may have built up over his career. Reading along:

“We have thermonuclear capabilities. I am absolutely sure. We are very clear on this point. If you hit a city with one of these you are talking about 50,000 to 1,00,000 deaths,” the NSA said.

Just saying so repeatedly will not cut it. Also, does anybody else find such casual mention of deaths more horrifying than Santhanam's statements?

One can understand where Narayanan is coming from: after all, proclaiming to the whole world that our hydrogen bombs are duds is not exactly good for the morale of the country and would cause our enemies quite a lot of satisfaction, but going after those who are interested in the truth doesn't serve any purpose, either.

Haskell, monads, graph theory and the puzzle that took 19 years to solve

Well, 'solve' is actually a misnomer, since it turns out that the puzzle doesn't have a solution (at least that's what my code tells me). Here's the puzzle:

Given the figure below, find a path from point A to point B that crosses every edge line segment exactly once:

I came upon this when I was in college, and spent an hour or so on it, trying out different paths by hand, but could not find a solution.

Nineteen years later, The Communications of the ACM carries an article on the P=NP question, which triggers an impulse in me to read up more on the complexity of algorithms, and I learn about graph theory, DFS, BFS, the entire works. Quite a fascinating subject. Anyway, the upshot of all this is that I realize that there is a formal method of solving the puzzle that had piqued my curiosity nearly two decades ago.

Coincidentally, my copy of Real World Haskell arrives at my doorstep at around the same time I am thinking of whipping up some code to solve the puzzle. Learn Haskell, solve puzzle. One stone, two birds.

The first thing is to come up with the data structures. Not too difficult (apologies for the screwed up formatting -- getting all the tabs correct in Blogger would probably take me four hours):

type Node = Int
type Edge = (Node, Node)
type Path = [Node]
type Graph = ([Node],[Edge])

theGraph :: Graph
theGraph = ([1,2,3,4,5,6], [(1,2),(1,3),(1,4),(1,2),
(2,3),(3,4),(1,4),(2,5),
(3,5),(3,6),(4,6),(1,5),
(5,6),(1,6),(1,5),(1,6)])

One of the options I considered initially was to model the direction of the path, something along the lines of

type Path = [(Edge,Direction)]

with Direction indicating whether we are going forward or backward, but it turns out that this was not required.

Having gotten the data structures in place, it's just a question of routine code to put together the helper functions that will be needed:

-- to check whether two edges are the same [(1,2) is equal to (2,1)]
edgeEq :: Edge -> Edge -> Bool
edgeEq e1 e2 = e11 == e21 && e12 == e22 ||
e11 == e22 && e12 == e21
where e11 = fst e1
e12 = snd e1
e21 = fst e2
e22 = snd e2

-- get all the edges joined at a node
getEdges :: Node -> [Edge]
getEdges node = [edge | edge <- snd theGraph, fst edge == node || snd edge == node]

-- get the node at the other end of an edge
getOtherEnd :: Node -> Edge ->Node
getOtherEnd node edge = if fst edge == node then snd edge else fst edge

-- get all the neighbours for a node
getNeighbours :: Node -> [Node]
getNeighbours node = map (getOtherEnd node) (getEdges node)

-- converts a path into a list of edges (e.g. [1,2,3,2] to [(1,2),(2,3),(3,2)]
buildEdges :: Path -> [Edge]
buildEdges path | null path || length path == 1 = []
| otherwise = (head path, head (tail path)) : buildEdges (tail path)

-- get the list of neighbouring nodes that are yet to be visited in the current path
getUnvisitedNeighbours :: Node -> Path -> [Node]
getUnvisitedNeighbours node path = map (getOtherEnd node) untravelledEdges
where untravelledEdges = deleteFirstsBy edgeEq (getEdges node) (buildEdges path)

-- check whether a given path is a solution
isSolution :: Path -> Bool
isSolution path = head path == 5 && last path == 6 && length path == length (snd theGraph) + 1

The astute reader will observe that the graph object -- is it OK to call things 'objects' in Haskell? -- is baked into the solution; I initially had a version where the graph object was passed as a parameter to every function, but this made things more verbose, and anyway, my objective was not to produce a graph library, but to solve the puzzle.

With that out of the way, time to move on to the actual algorithm. The algorithm is a DFS brute search, where we start at a node (note that the area outside the figure is also modelled as a node), choose one of its unvisited neighbours, choose one of the neighbour's unvisited neighbours, and so on, till we run out of neighbours to visit. Check the path to see if we have covered all the edges and if the path is bookended by the start and end nodes that are of interest to us, and we have our solution. An NP-hard problem, BTW.

It's obvious that recursion is needed here, but I was not sure how to handle the enumeration of the different branches, the backtracking from a dead end, and so on in Haskell, considering that looping is frowned upon, and the strongly typed nature of the language implies that both the if and else clauses should return the same type, i.e. you cannot do the equivalent of:

if <path is a solution>
then <print solution>
else <add next neighbour and try again>

While working on the solution, I was also reading up on monads, and man, are they a pain to wrap your head around. But luckily I ran into [*] Monads as containers (and its sibling Monads as computation, which I'm still digesting), where I learned that a list is also a monad, and we can do stuff like take a list, apply a function that produces a list, and end up with a flat list, so to speak (yeah, we don't need monads for this, a simple map and concat are enough, but I learned this in hindsight, after realizing that >>= was exactly what I was looking for). Anyway, that sort of nails the algorithm:

-- build a list of candidate paths for a given path
getNextChoices :: Path -> [Path]
getNextChoices path = nub (unvisitedNodes >>= (\x -> [reverse (x : reverse path)])) -- hack to append to end of a list
where unvisitedNodes = getUnvisitedNeighbours (last path) path

-- filter out all the solutions from a given list of candidate paths
findSolutions :: [Path] -> [Path]
findSolutions paths = filter isSolution (nub paths)

-- find all the solutions starting from a given list of candidate paths.
-- invoked with a single node path, i.e. solve [[1]]
solve :: [Path] -> [Path]
solve paths = if null choices
then findSolutions paths
else solve choices
where choices = (paths >>= getNextChoices)

solve' :: [Path]
solve' = solve [[5]]

From All About Monads:

One use of functions which return lists is to represent ambiguous computations -- that is computations which may have 0, 1, or more allowed outcomes. In a computation composed from ambiguous subcomputations, the ambiguity may compound, or it may eventually resolve into a single allowed outcome or no allowed outcome at all. During this process, the set of possible computational states is represented as a list. The List monad thus embodies a strategy for performing simultaneous computations along all allowed paths of an ambiguous computation.

The above algorithm is not exactly an ambiguous computation, but the bit about "performing simultaneous computations along all allowed paths" sure resonates with its structure.

And now for the denouement, which by the way, takes a looong time (remember the NP-hardness):

*Main> solve'
[]

Nope, still no solution.

[*] It doesn't reflect too well on a book if I still have to rely on Google to help me out. I'm looking at you, "Real World Haskell".

Thank you

Here's an example of what's wrong with our country:



Salsa-dancing, shopping-at-Marks-and-Spencers investment bankers -- yeah, this is the most representative Indian demographic.

And using Phil Collins' Another Day in Paradise as the investment banker's favourite song? These guys won't know it if irony jumped up and bit them on their asses.

Thought for the day

A helpful analogy to understand the value of static typing is to look at it as putting pieces into a jigsaw puzzle. In Haskell, if a piece has the wrong shape, it simply won't fit. In a dynamically typed language, all the pieces are 1x1 squares and always fit, so you have to constantly examine the resulting picture and check (through testing) whether it's correct.
-- From Real World Haskell

Little things

Firefox: Allow one the option of saving the password for a web site after the site has received the password and has indicated successful authentication.

IE: Prompt for saving the password before sending the request, which may result in storing an incorrect password (because of a typo).

Is it just me

... or does this image remind one of -- never mind.



(yeah, that's right, guy #1, move your left hand towards guy #3, just a little higher... perfect! Hold it right there. Guy #3, take your left hand, and...)

Exports to touch same level as last year?

... according to this story. Quite unlikely, considering the quite steep year-on-year dips in the export figures for the initial months of the year.

Bloggots

Dear Farrukh Dhondy,

I have been a regular reader of your columns in The Deccan Chronicle, and have always enjoyed your wit and intelligent insights. However, you have outdone yourself today:

Neither is there much evidence in favour of the bloggots (blogging idiots) who contend that Afghanistan is strategically important because someone somewhere wants to lay a pipeline through it to send petrol or gas to someone else and earn zillions of dollars thereby. Look at a contour map of Afghanistan (and get a life)!

Bloggots. Take two unrelated words, 'blogging' and 'idiots', conflate them together, thereby forming a new word that was simply begging to be coined, a word that succinctly captures the misplaced contempt that professional columnists (aka people who have a life as compared to us poor bloggots) have for folks who are doing an end run around them, and that too for free, and voila, there's your winner for the next year's competition.

Sincerely yours,

Bloggot #76981

P.S. About the whole Afghanistan thing: I suggest you Google for these terms: "grand chessboard", "Melvin Lattimore" and "Ali Mohammed". Spending some time at History Commons and the RI Data Dump won't hurt, either.

P.P.S. And I have been wondering about this for a long time: who the $%@& is Bachchoo?

Pension funds

Here's an example (via Mish Shedlock) of the dangers we would be exposing ourselves to if we allowed our pension funds to be invested in -- ahem -- "non-moribund investment patterns":

As of March 31, Calpers's $17.6 billion real-estate portfolio, a majority of which is invested in commercial properties while about 5% is invested in residential, reported a one-year decline of about 35% in its value.

I'd take a measly inflation-adjusted single digit return any day, thank you very much.

India aims for robust GDP growth despite drought

The Commerce Minister has opined that we can maintain our GDP growth in the current year at the same level as the previous one. Good to know that; the only problem is that the entire article contains not a single factual argument that supports his statement. Things like

"Our domestic demand and consumption is strong. Fundamentally, our economy is strong"

and

"India keeps substantial buffer stocks of food grains after our two successive years of buffer [Ed: I think he meant 'bumper'] crops. We have enough of what we have to sustain availability of food"

and

"We are not overlooking the challenges that we have. At the same time, we are not overwhelmed by them...we hope that this situation will not be there when the next sowing season comes in January"

are not exactly confidence-inspiring, absent any convincing arguments.

I came across this piece immediately after reading an investment advisory about the impact of the drought on the economy -- the detailed analysis it contains shows up the hollowness of these statements even more starkly.

Adieu to social networking

Last week I deleted my Facebook and Orkut profiles, for reasons I've mentioned elsewhere. I am going to delete my Twitter and LinkedIn accounts as well, but haven't gotten around to it yet. Maybe I'll spare LinkedIn, but Twitter has to go -- no two ways about it.

Thank you

Someone finally calls out on this pretentiousness:


This goes not just for tweeting twats, but also for blog commenters.

You give research a bad name - Part 2

From Yahoo:

A new piece of research suggests that what an organization promises to employees-training opportunities, benefits, compensation, etc.-do not matter nearly as much as what the organization actually delivers.

Samantha Montes and co-author David Zweig, professors at the Rotman School of Management and the University of Toronto Scarborough, have found that the influence of promises has little effect on employee's emotional reactions toward the organization, their intentions to stay with the organization, and intentions to engage in citizenship behaviours.

In their study paper, the authors write that people care more about what they receive from their organization, not what they were promised.

Gee, who would've thunk that?

Operators are standing by as we speak

Yeah, that's exactly what the world needs more of right now: a gold-plated guest house complex, when millions are suffering from disease, malnutrition and other crises.

Here's an idea

Abdul Kalam's supposed humiliation at the hands of the Continental Airlines security staff has kicked off a much needed debate on the privileges our so called VIPs enjoy. Here's an idea: instead of referring to these folks as VIPs, why not start calling them SLs (short for Security Liability)? This would a) take away the sheen associated with the original tag and b) lower the cost to the exchequer (the assumption being that the politicos would be shamed into requesting that they do not want to be provided security, owing to the negative connotation of the new tag).

The Rajapaksa interview

The Hindu is carrying an interview with the Sri Lankan president. Most of his answers are politically correct and are what we want to hear -- man, he's one smooth operator, alright -- but this one exposes his true colours:

Q: There has been international concern over the assaults and pressures on journalists in Sri Lanka. Some of these journalists were your personal friends, especially Lasantha Wickrematunge [Editor of The Sunday Leader] who was gunned down in January 2009. Then, in June, a Tamil woman journalist [Krishni Ifhan née Kandasamy of Internews] was abducted in Colombo by unidentified persons [who questioned her for several hours before releasing her in Kandy].

A: Most of these cases were created, I would say. If you fight someone in the street and that man comes and hits you, can the government take responsibility? But we have not done anything against journalists even when they attack us.

Nice dodge.

BTW, in case you haven't done so already, go and read 'And then they came for me', Lasantha Wickrematunge's voice from beyond the grave -- without doubt the most poignant thing I've read in a long while.