Author name: S Anand

Software for my new laptop

/ Top 10 lists / 11 Comments

And so, thanks to Infosys Consulting being spun off as a separate legal entity in the UK, I got my new laptop. (Because our old laptops were legally the assets of Infosys Technologies Ltd, and not Infosys Consulting Inc. Weirder things have happened, but who’s complaining?)

My old Toshiba Portege A200 has been replaced by a Dell Latitude D420 (which I was dreaming for, after having just read Jeff’s post on big laptops).

Dell Latitude D420

Firstly, it’s light. I thought my Toshiba was light compared to the Dell monsters others had, but this weighs 1.4 kgs! Secondly, it’s thin. It’s thinner than some of the paper notebooks I used to carry. It’s hard to imagine where we will be in 5-7 years time if innovations keep rolling in at this rate.

There were only two (minor) problems I saw with it. It didn’t have an S-Video port — so I can’t watch movies on TV. And it had a fairly small (12″) screen. Being a wide screen, I get a lot less height than I used to. I’m still having some trouble getting used to that, especially when browsing tall pages but it’s a good laptop for playing games such as 올인구조대.

My weekend was like a kid in a candy store. Here’s what I did.

Uninstalled useless software: The laptop came with Roxio Easy CD Creator 5 Basic and PowerDVD 5.1. I got rid of them.

Copied all my files: I had about 25GB of data (15GB of music, 5 GB of books, 2 GB of video, 3GB of work). This was a bit tricky: some of my data was in SVN repositories, and I had to migrate them.

Configured the new system by literally running through each entry in the control panel, and ensuring that it’s the same as my old machine. Most of my changes are spartan (aimed at less eye-candy, usually). For example,

  • Display: I switch to Windows Classic and a black background. I used to do this because it takes less memory, but with 1GB of RAM, that’s no longer a consideration. I just got used to this. I also turn off all special effects, and remove everything except the Recycle Bin from my desktop. But the really useful thing is to turn on ClearType.
  • Taskbar and Start Menu: I switch to the Classic Start Menu, and turn off everything. Here’s what mine looks like now.Start Menu settings
  • Toolbars: I like my toolbars to fit on one line. So I do some heavy customisation with the Internet Explorer toolbar to shrink it to a line. Similarly on the desktop toolbars.

Installed software. This is the fun part. I’ve made a number of changes to my software inventory.

And finally, after reinstalling my SVN repository and copying my WinAmp playlists, Firefox bookmarks, etc, my new laptop feels as good as old.

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Playing sounds backwards

/ How I do things / 7 Comments

You can play a video backwards and still recognise the scenes quite well. Can you do that with sound?

I tried it on this Bryan Adams clip of Summer of ’69 (mp3). When played backwards (mp3), it almost sounds like Arabic!

Instruments sound weird backwards too, like the guitar played backwards and drums played backwards.

It’s seems obvious once you see the wave file. The picture below shows the guitar. The sounds are clearly not symmetric left to right.

Sound wave diagram of a guitar

Whereas this guitar is a lot more symmetric, and doesn’t sound too different backwards.

Sound wave diagram of another guitar

So how come we can’t recognise sounds played backwards, but can recognise video played backwards? (Initially, I thought it was a trivial question. But I couldn’t find a trivial answer. The question may be subtler than it looks.)

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Visualisation – locating hubs

/ Visualisation / 5 Comments

OK, we agree we need to centralise more. But do we really need additional hubs? If so, where?

We’d shown that this bank could further centralise 55%. They had 10 regional hubs. We felt these weren’t enough. But how to prove it?

For regional activities, the key factor is distance. (That’s why they’re regional and not central.) For example, cheque clearing can be delayed at most one day, to transfer the cheque to a nearby hub. Shipping them all to, say Gurgaon, would take 2-3 days and that’s too long.

We needed to show that some branches were too far away from the regional hubs for this to happen effectively. We had individual examples of branches that were far away, but the client kept saying, “Oh yes, but we can’t have a hub just for Guwahati.” We had a list of their 350+ branches, and their 10 regional hubs. The question was, were there many branches very far from a hub? (We agreed that 300 km was the acceptable “range” of a hub.)

This is a tougher problem than it looks. We needed the latitude and longitude of every city that had a branch. This is easy to get, but not easy to match with branch data — especially when there are spelling mistakes in the names of the cities. This was where I learnt how to reconcile data.

Using the Haversine formula to compute distances between latitudes and longitudes, we finally came up with this (messy) sheet. The last column shows the minimum distance to a hub for each branch. The items in red were more than 300 km. We were proved right. They needed more hubs.

Distance of each branch from the closest hub

But where to locate new hubs? We initially tried some fancy algorithms, but our clients were lost a long time ago. So we plotted the branches on the map, along with the hubs, and the range of the hubs. (This wasn’t a projection or anything — I just plotted latitudes and longitudes on a X-Y scatter plot, put an India map below, and tweaked it.)

India map showing branches and hub coverage

Then people got it. They’d take one look at the map, and say “Ah, so we have uncovered regions in UP, Haryana and Karnataka. OK, I’ll put a hub there. Move on.”

This is an obvious thing to do. But it takes effort. Which is why, sometimes: it’s better that the person who’s thinking of the slides is not the one who makes the slides — just so he doesn’t shy away from good, tough slides.

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