MGHPCC Progress

Great pictures and video of the building going up! Check them out here.

Heap Sort

Holidays and a new job have been occupying my attention for the past couple of weeks but, fear not, I’m still pursuing my algorithms project. Next up on the agenda is Heap Sort.

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VMWare Fusion Disk Resize and Grow NTFS Partition

Use Gnome Partition Editor (gpartd).

Fusion 2.x allows you to resize a disk but does not grow the underlying NTFS partition. Once you’ve resized the disk using the vmware gui, you need to grow the partition. You can get gpartd on a livecd; the application groks a wide variety of file systems including NTFS. Read more »

Improved Merge Sort

So the first comment that I received for the Merge Sort post pointed out that my implementation was not very efficient. While the code correctly implements the algorithm, practical choices (such as choice of data structure) make the code very inefficient – the code I show will definitely not execute in O(nlogn) time. I took another swing at the Lisp code, paying closer attention to performance issues.

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Merge Sort

Merge sort is another simple algorithm that introduces a fairly powerful concept: Divide and Conquer. Like the previous example, we’ll look at the algorithm, a Lisp implementation then look a bit at running time.

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Insertion Sort

So the first algorithm that we’re going to work on is insertion sort. This is a very simple/intuitive routine, the easiest way to think about how it works is to consider how you might sort a handful of cards.

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More interesting visualization

Nice visualization of the financial markets.

QuickEdit mode in DOS Shell

Funny the things you suffer with. I’ve been using cygwin a lot on windows lately and decided to see if it had better support for cut and paste than the DOS shell does. Quick google seach shows that it’s been available for six years on windows in DOS shell. For anyone else not “in the know”…
If you want mouse select, copy, paste in a DOS shell you can on win2k and above by enabling “QuickEdit Mode” from the shell’s property menu.

Utility storage thoughts…

I’ve had an interesting realization recently. I always viewed the utility storage model from the perspective that data would “live” on my machines and that I would “back up” in the cloud. However, as I’ve started using S3 mounted as a drive on my home machines (Jungle Disk + NetDrive), I’ve realized that it won’t work this way at all. Working with these programs and futzing with their respective caches, I’ve realized that virtually all of my data will eventually live in the cloud and only a limited working set cached locally.

Maybe not earth-shattering for you but certainly a change of perspective for me…

Pandora

Damn! I like this a lot. Pandora is a streaming music service where you build personalized stations. To build a new station, you pick a song that exemplifies the style of music you want the station to play (e.g., looking for jam?; initialize your station with a Phish or Grateful Dead tune) the service plays your tune then starts to play tunes like that one. As the music plays, you can go in and gives thumbs up/down to songs as they go by. The service adjusts what it plays on the station based on the feedback. The cool thing is that you start out with tunes you know then the service starts playing/recommending stuff you don’t know; solves the “how do I discover new stuff without having to put up with tons of crappy radio noise” problem.

I haven’t been using the service long but I really like what I’ve heard so far!

Check it out at www.pandora.com.

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