I started on a longish posting tonight and wanted to include some hand-drawn diagrams when I realized (again) how much I still hate the whole process of including images in web pages. Ten years later and it’s still just a total drag. I swear I originally got into computer graphics because I hated scanning physical art.

A remarkable collection of illustrated and animated Sorting Algorithms with links to Java source code. Seeing how Quicksort compares to other methods of sorting reinforces why it’s one of the most important algorithms in current use. This page has examples of Quicksort implementations in a bunch of languages.

Quicksort uses a recursive divide and conquor approach to sorting lists. It was created by Tony Hoare in 1960.

Here’s another QuickSort animation which shows exactly what is happening during the sort. It’s a little slow, but after watching one or two iterations, it’s very, very easy to see what is happening.

While I don’t understand how they measure the O(n) space optimization, I love the thinking that goes into these.

No church bells this year, at least none that seemed to correspond to anything. I walked by two fire stations; Engine 5 is across the street from my apartment, Ladder 3 is on 13th Street between 3rd and 4th. There was some sort of family lunch inside the ladder 3 station house, I passed by quickly not wanting to gawk. Engine 5 had flowers outside the door. There weren’t any earlier in the morning when we headed to the playground at Tompkin’s Square.

For much of the day I was trying to figure out why I felt a certain numbness to this anniversary. Today was another milestone in time, but September 11th, 2001 has never left me. Earlier I looked at several photos and read a few stories which hardened the pit in my stomach, but in some ways it felt like I was forcing the pain. Maybe that’s what today is supposed to do.

I haven’t forgotten. There are constant reminders and, as one friend described it, there is “a certain low level paranoia about living in New York City.” I notice it most when I’m not here.

The Towers of Light are back and I can see them from our front window. I considered walking down to get a closer look and some photos, but decided to stay in and work instead.

September 11, 2003
September 11, 2002
September 11, 2001