I was returning home from office and as
soon as I opened the front door, my two-year-old daughter sprung on me and took
me to the ground. I played with her, listened to the garbled stories she had to
narrate and a good 30 minutes went by. I went to freshen up and came back to
sit down in the living room sofa. My daughter and wife were engaged in their
own activities, as I was staring emptily into the TV that hadn’t been switched
on, sulking about the week and the day that had been unproductive so far – neither
a single creative idea nor a single worthwhile piece of work done. Apparently
my wife was planning to make Murungakaai
(drumstick) Sambar for the evening and realised that we had ran out of the
key ingredient murungakaai. She came
out of the kitchen and seeing me loitering away, ordered me to fetch some from
the market. Angry as I was for not being productive, I took on her request
grudgingly. I put on a blue t-shirt and as per custom, carried my daughter to
the market.
Sulking all the way, I entered the
vegetable section while my daughter happily got down and homed in on the candy
section. While she was making her selection, I was going through the
assortment of murungakaai, all the while not letting her out of my
peripheral vision. As most Tamils
would confirm, selection of the perfect murungakaai
is a skill in and of itself – neither too thick nor too thin, neither too
long nor too short, neither too fresh nor too ripe. If the perfect kaai
is not used, the Sambar would be a
disaster, an outcome that my wife does not take lightly to. Most young people
gain this particular skill by watching their parents and I am no exception to
this phenomenon, as I remember the nuances of vegetable selection my mother
used to teach me whenever we went to the market together.
Unfortunately, this evening the perfect
one was not to be found - adding to the frustration of not being able to solve
the problem of missing data in time series at work. As I ran my fingers through
this one particular kaai, I found
that it was not perfect. In my opinion, Murugakaai is
a very peculiar vegetable. Unlike the other bulky and round veggies, it is long and slender and has small swellings at regular intervals much like
the knuckles of the human finger. The ‘knuckles’
are largest in the middle of the vegetable and taper uniformly towards both the
ends. However, this particular kaai that
was in my hand was missing some of the ‘knuckles’.
It hit me like an apple falling from very high up a tree. I realised that
the missing knuckles’ sizes can be
predicted from the sizes of the adjacent ‘knuckles’
through imputation, as the sizes were correlated in space. By now, my daughter
had already made her pick and was eagerly waiting for me to give her the nod
and bill it. I grabbed the imperfect kaai
and went straight to the counter. I couldn't wait anymore as I desperately had
to Google. I paid the cashier an amount that was within the range suggested by
my middle class brain’s pricing conventions.
I rushed home as my daughter kept uttering
‘kaai…kaai…kaai’, one of her favourite
words in her every growing vocabulary. I blasted the door open, transferred my
daughter to the ground and handled over the kaai
to my wife with a triumphant smile. Without being too impressed, she
half-heartedly accepted my submission, while staring confusedly at me for having that smug
across my face. It took me a while to realise that I was smiling from corner to
corner and corrected myself. I turned around and reached for my
phone and started to Google ‘impute missing data in cross-sectional time series’
and the results it threw were to my utter joy. And I resumed my smile. My wife
silently observing all these, yelled from the kitchen, “You can thank me later
for the discovery!” She knew that I had found something that was useful for my
work and that she in her own little way helped me get there. I merely nodded
and smiled.
The Murungakaai
Sambar came out wonderfully and we
all sat down in a circle to enjoy dinner. I exchanged a smile with my wife and
nodded my gratitude to her, which she acknowledged by helping me with another
serving of the tasty meal.
