Wednesday, March 4, 2015

Monty Hall Problem; a short spreadsheet looking at whether it makes sense to switch

A simple spreadsheet looking at the Monty Hall Problem, referenced in today's "link a day" post by Sudhir Kamath

Here's the link to the spreadsheet.

It's not even close. You should always switch. If you imagine doing this 50 times it becomes quite obvious - in a single instance (like when you are on the game show) it might be harder to process. 

In a 100 instances, you will pick a goat on the first draw roughly 67 times, the host will open another door with goats (a 100 times), so there are only 33 goats to go and 67 cars left - all of which are behind the third door, in the respective cases.

Credit to Aseem Kaul for the most elegant description of the logic for switching:
You know there's a two thirds chance that you picked the wrong door, so you know there's a two thirds chance the other door is the right one.

Monday, November 15, 2010

Waiting for the Light

It's been a few weeks since I started the morning madness. Inspired by many people, Galen Rowell in particular, to seek the magic hour, I've been coming to the Westport, CT, beach every weekend morning for the past few weeks trying my hand at capturing a spectacular sunrise. Winter has more or less arrived - it certainly feels that way in the hour before sunrise on an open beach with a stiff breeze. It is no mean feat trying to control a camera in this kind of cold; Eastern Mountain Sports in Stamford will certainly be making their quarterly numbers this time around, what with all the gear I've bought just trying to stay warm. This one is by no means the best sunrise I've seen since I began this adventure, but this is the first one to come out relatively well. I will be posting more pictures of sunrises as I get them but I wanted to write a little more on the topic of sunrises (and sunsets) in general. My recent re-discovery of photography has been very rewarding in many ways. For one, I wake up well before dawn - it was the John Deere tractor that last got me this excited - and take in the morning ocean air instead of reaching for the Blackberry to bear witness to more corporate lunacy and incompetence. Many of us go through sunrises and sunsets our whole lives without quite so often pausing to watch and wonder in amazement at this natural phenomenon that happens with perfect regularity. I find it strange that it was in trying to make pictures that I've re-discovered the beauty of the sun at the horizon and nowadays I pause ever so often in the morning and evening to take in the views and . It has taken me back to the decade in Mussoorie, home to some of the most awe inspiring sunsets on the planet (with its winter line phenomenon). And this is just a sunrise. When was the last time you paused to witness something truly amazing in nature? When was the last time you sought it out purposefully? Try it. It might just change how you look at things and what you value. And while I was labouring over this post, I managed to get this sunset, again at the Westport, CT, beach. It's getting better, as you can see.

Monday, November 1, 2010

Aakrosh, Film Review

Watched Aakrosh yesterday. Story purportedly about honour killings. Ranvir Sena meets Nitish Katara type situation, along with copying from Company (tera paas aur koi choice hai?) and Mirch Masala and sundry other films, including a sequence that reminds us of Ajay Devgan's debut film Phool Aur Kaante. Casting is superb, but the lead characters (Ajay Devgan and Akshaye Khanna), who otherwise put in credible performances, have too much glamour which distracts - imagine fitted shirts, ties, and jackets in the hinterland without breaking a sweat. Paresh Rawal surprisingly overacts but gives you the creeps. Bipasha is a complete misfit and really has no reason to exist in the film. This genre (aka 'Heartland Caste Violence Porn') is really Prakash Jha territory in the modern day (remember Apharan?) and the attempt at that kind of crude dialogue 'uska future kharaab kar denge' (Aakrosh) falls flat compared with 'first timer log hai, kahin nervusiya gaya to bal-under ho jayega' (Apharan). Lots of brutal violence, most of which is likely true; makes you sick to the stomach but not as much as Bandit Queen, which required therapy afterwards. Worth watching, if only to see what goes on in the heartland and convince yourself that 'this doesn't happen in the cities' and that the Taliban live only in Afghanistan. I'm certain you're aware ki that apathetic self-comforting is delusional.