Big Garden Birdwatch 2006

This morning my daughter Zoe (aged 10) took part in the RSPB's Big Garden Birdwatch. She sat at at her bedroom window between 8 and 9am and recorded the maximum number of each type of bird she saw at any given moment in the grounds of our flats.  I provided backup support by fetching the binoculars when they were needed and by supplying a (vegetarian) bacon sandwich at the halfway point.  The results were much as I would have expected:

Blackbird - 3

Magpie - 2

Wood pigeon - 7

Wren - 1

The 'at any given moment' condition ensures that the same bird never gets counted more than once.

Signs of Spring?

Walked round the lakes with Zoe this afternoon.  No sign of the pair of Egyptian geese on the large lake.  Zoe thinks they must be building a nest somewhere.  Also no sign of the 5-7 cormorants that were there up until last weekend.  This winter, cormorants have been more common on the Reading University lakes than they have been at Farnborough North.   A few years ago it was the other way round. 

The shoveller ducks were still present.  The warm weather hasn't deceived them into moving back north, which is just as well as another cold spell is forecast for the middle of next week.

Another Red Kite

Walking back from the Co-op on Erleigh Road with Zoe at lunch time, there was a red kite high up, circling.  We watched it drift southwards and then turn back north again.

In the news a few weeks ago was a report of a red kite over central London.  Apparently a few hundred years ago they were common there, scavenging on rubbish.

Advice to Beginner Programmers

 From Beginning Python by Peter C. Norton et al. (Wrox, 2005):

The trend in personal computers has been away from reliability and toward software being built on top of other, unreliable, software.  The results that you live with might have you believing that computers are malicious and arbitrary beasts, existing to taunt you with unbearable amounts of extra work and various harassments while you're already trying to accomplish something.  If you do feel this way, you already know that you're not alone.  However, after you've learned how to program, you gain an understanding of how this situation has come to pass, and perhaps you'll find that you can do better than some of the programmers whose software you have used.

This make a refreshing change from the gee-whizzery that seems to infect most beginners books.

State the Problem Before Describing the Solution

Today I came across the following short note on Leslie Lamport's site:

State the Problem Before Describing the Solution, Leslie. Lamport, ACM SIGSOFT Software Engineering Notes 3, 1 (January 1978) 26

The idea is that, when writing a paper, you should precisely state the correctness requirements for any solution before you present your proposed solution.  Lamport points out that this idea can also be used when writing programs.  The separation of the requirements from the solution is similar to Michael Jackson's insistence that requirements be written in terms of domain concepts rather than solution concepts.