The sea bass and the salmon

Its funny how complex (or so i thought) concepts can be so easily explained using simple real life examples.
To explain this, I will need to cite the example to the sea bass and salmon which was so aptly utilized to explain the Bayes classification to us. Consider that we need to create an automated process which can differentiate between salmon and sea bass. For this, we may need to consider features such as size, color, texture maybe. Of course, certain assumptions need to be in place such as the camera position: we don't want one half of the salmon coming and the other half of a sea bass coming....features may get indistinguishable. So, if we consider their probability distributions to be gaussian (the simplest case) then for minimum error in identification, the decision boundary needs to lie at the point of intersection between the two distributions. (As shown in figure)
However, here we introduce a new concept: minimum risk. Many times, it happens that the cost of identifying a salmon as a sea bass is not the same as identifying a sea bass as a salmon.
The salmon is a costlier fish and if a customer gets a sea bass instead, he can very likely sue and create trouble. So, it is better to create error in identifying a salmon as a sea bass (a customer ending up with a costlier fish instead of a cheaper one would most likely be happy) than vice versa.
This leads to the minimum risk which will shift the decision boundary to either direction depending on the cost of error.
Hence, tougher concepts can be explained in a layman manner ....and thanks to Dr S, it was an excellent and highly enjoyable lecture.....

PS: By probability distribution, I mean the probability of salmon/ sea bass occuring with respect to a particular feature i.e a plot of the feature (x) Vs the probability (y)...hope it makes things clearer.

Studies.....

It seems I have left the foremost topic unsaid (unwritten lets say). With all the good intentions at heart, I and many other folks like me set out from the known to the unknown trying to learn the unknown ....with confidence unknown....did i make any sense here?
So, anyway, I arrived on campus and embarked on the perilous journey through the courses. Having taken two highly rigorous courses, it would be no surprise to know that even a non slogger like me has to rack her gray cells if she has any intention of completing her assignments on time. The assignments are not the (Ctrl + C, Ctrl + V) tuple that we are so familiar with. In fact, each small exercise has a catch which has you wondering if what you finally wrote as the answer has anything plausible or accurate written in it. The lectures last for about an hour and are for about 3 hours in a week but if you think you are being let off easy, think again. I doubt if any indian professor could squeeze in so much matter in a month as these guys here do in lecture. A hyperbole i admit but just trying to make a point here.
However, if whatever i said sounded negative here, then probably you should overlook it coz, everything said and done, i am simply loving the courses here. The profs are terribly passionate about their work and are so dedicated that you end up getting equally enthusiastic about the subject and the assignments leave so many ambiguous points that you end up figuring a lot of things which i wouldn't have bothered about had i not been mandatorily given such a task.
The system here is simply fantastic and I am enjoying every single moment of it!!!!!

Cooking...

The kitchen is perhaps today's most neglected section of the house. (a very personal view, no judgments intended) so i am sure its not surprising that i was not found there very often back at my place. However, i did know a spoon from a knife and yes, had tried my hand at several items at home. My brother and khapak bear testimony to that fact...(apart from my parents that is ), being the guinea pigs for the various experiments. However, cooking every single day is really a total different ball game. Cooking from the scratch (yup, we don't really enjoy tv dinners)is a novel experience with something new to learn everyday. Firstly, i would like to mention here that we don't use cooking gas out here. There are heating coils which makes cooking subtly different; we do not require lighters and stuff nor match boxes but yes, vegetables still get burnt and yes, milk still boils over. Secondly, cooking in a group has some other things to take care of: the quantity needs to be correct and (more importantly) proportion needs to be accurate. Adding extra rice to a meal involves a careful addition of water. I have already realized that since rice turned out to be a very runny substance with a gravylike appearance.
Similarly, chicken cooked in the oven (not microwave) is totally different from chicken cooked in the frying pan...it not only tastes better but also takes way more time to cook.
Then, thanks to the weather here, i can add ginger to the tea at any time and not worry about the milk (which is rather thinner here than back at home).
I still have to try my hands at sweet dishes and i am sure we (my roomie and i) can make really "fundoo" dishes when we feel like it. Right from making sambar to brinjal/eggplant to egg fried rice to tandoori chicken, it all adds up to my culinary skills and so far I haven't yet made something inedible which propels me to try my hand at making some slightly more ambitious dishes. At this point i remember a wonderful quote by Asha Bhonsle "gawaiye khawaiye hote hai"...so i think i'll conclude this post with her words....

Moods.... and Weather

It is time for me to venture to a more exciting theme so here goes.
I though i will mention about the .... weather at Mizzou.
First reaction? Stereotypical topic? Typical beginner's conversation?
A shy and hesitant broach at a very comfortable and speakable topic?
No, no my friend, it would take a really confident person to talk about Mizzou weather.
If I were to try and describe a drunken man's walking pattern (it is supposed to be one tough curve) or perhaps describe shapes of clouds (not the fluffy bubble gum things we used to draw as kids!) or perhaps describe a woman's moods as quoted by Lord Byron and the like, well then I WOULD be able to define the weather here.
It is amazing how it is possible to look out of the window in the morning and exclaim at the bright sunny morn only to find yourself drenched as soon as you get out of your flat a wee while later.
Often, the chilly breeze can bite you while at the same time the sun shines brightly at you.
What can I say? This amazing multitude of weather conditions makes each day tougher to classify than features. A walk to the library can be hot and sweaty one way and cold and chilly the other. The beautiful trees change color as the season progresses and makes me awestruck at nature's beauty.
To sum it up, it is better to leave some things unsolved and simply enjoy the games played by nature.
It makes each day a different one and keeps me amazed.
So, here's to the Mizzou weather!!!!

The trail....

After much nagging, pleading and beseeching, the "Famous Five" of us set out to the Twin Lakes.
If you guys don't know what a trail is, well it is some kind of glorified tekdi with loads of greenery and natural beauty. The path is unending....apparently u can go to texas through the same path and i suppose many folks here might have done that too!!!
Well, back to the trail......we walked....then walked....then walked......and then guess what?????
We walked again!!!!! (Surprise,surprise!)
Anyway, the walk was not quite short, but beautiful and there were these several exercise spots on the way for the health fanatics to vent their energies on.
We reached the spot after some time....the lake was....placid and......simply beautiful. It was like one of those picturesque photos you see in calenders which seem too pretty to be true and there it was, right before "me very own eyes"!!!! There was even a place there for fishing and another spot where dog owners can let their dogs loose and let them create havoc :)
It was really a treat and even though i was worn out, the experience was nothing short of......lovely! :)