* Posts by Matthew

5 posts • joined 24 Jun 2007

Judge rules Gore's film an inconvenient catalogue of errors


Instead of being a skeptic, why not just care

Are you a climate change skeptic, tied at being laughed at, at parties, your own mother looks at you as if you're a holocausts denier?

Well Mat has the answer, you too can be invited back to those dinner parties and not look like an over bearing ass. It's simple. Just develop an abiding hatred of nature!

Try these simple lines.

"Of course global warming is real, but think if the beach-front property boom."

"Well have you ever actually met a polar bear, nasty, nasty things."

"I've got shares in that new Club Med startup in Greenland. So I driver a Hummer."

"Do you actually like cold summers." (deep mocking laugh)

"Of course it's real, but why on earth should I have to bear the cost of fixing it"

I know it sounds callous, but please stop debating the science, and just embrace your world view.


A US CERT reminder: The net is an insecure place


85% of all issues are fluff

If you can tell with any reliability which 85 bugs out of 100 are the crap ones, then you'll make a mint.

Same goes for the y2k stuff. 99.9% of the bugs were crap, and a waste of time time to fix, the problem is that that 0.1% that were really, really important are hard to pick out from all the rest :-).

I fixed hundreds of bugs over that period, of all of them, I know that only two would have actually caused anything other than cosmetic issues. One would have lead to aircraft not being tracked by a particular of radar system. The other would have caused a major car company to lose months of compliance and testing data. I would not like to have been flying on Jan 1 with that bug production code, but I had to find all the bugs to find that one.

I believe that the Nigerian government didn't pay for any Y2K work and they were only without water for 2 months and air traffic control, or that might be another urban myth.

Same goes for security bugs, I remember the internet going tits up for about a week because of a bug in MSSQL 2000, I wonder how much that cost.


Original thinking in a derivatives market


Paying the piper

I read the article with the hope of getting some insight into what actually drove the panic when it occurred and how things have changed since when the game got played in the late 80s. The only thing I walked away from it with was the reference to 'Black Swans' which I just ran away and read, and liked.

Now to my comment.

If someone had asked me 5 years ago what the end result would have been of giving 0.5% variable interest loans to people with a diminished ability to pay off the loan, a bad history with dealing with money, in a market with inflated house prices I could have predicted the first order effects in about 10 seconds.

A pocket calculator, let alone a bunch of PhD's banging away on keyboards would have made no difference to my predictions.

I could probably have a stab at the second order effects (given how the central banks have behaved). But my predictions would be a series of branches based on decisions that actual people made, not on some bulk property of the market. Anybody who claims that they can use bulk properties to predict how things will behave an a non-linear system is a liar.

The market shake-up wasn't caused by some freak confluence of events (black swan), bad models, or a lack of understanding of models. It was caused by the simple fact that your worst days comes straight your best days, parties start slowly, but end quickly, you might be able to ride the wave for minuets, but it breaks in seconds.

The sub prime market got used up like any resource, and when the was no place to expand to, it imploded. It's what we humans do to any resource, and it's what we'll do with oil, coal, uranium, the next round of financial regulation loop holes, p2p downloads and everything else.


Aussie bin Laden penetrates APEC security


God bless political comedy

These are the wacky kids who sent legal letters to Google over having their video REMOVED from youtube, and forced them to put it back up  God bless their souls.

If anybody wants to see truly gutsy political comedy, try and find the video of Norman Gunston at the famous dismissal speech of Goff Whitlam.


How to counter premature optimisation


Optimisation vs Buggy software

I agree with the author. Don't optimise until the end, only allow experts to play, and put clear explanations around the reason.

Having said that, I think some people may be getting hung up on the word 'optimisation' and think it equates to any change that improves the responsiveness/performance of an application.

If someone implements the wrong algorithm to solve a problem, or invents a problem, putting it right isn't optimisation it's bug fixing.

Example of evil optimisation:

A car race timing system back in the darkest 80s was using an IBM-XT to display the results as the cars crossed the line. To avoid using a multiply the really, really smart guy wrote 15 lines of hand crafted assembly that was smacked into the middle of the C. That code wasn't touched for 10 years, until I came along as a grad, and asked 'What does that do?'.

Not one person working in the company knew, I spent 3 days 'un-optimising' the code, which opened the code up to the compilers optimiser, and thus fixed a accuracy problem we were having. The smart guy solved the right problem on the day, but forgot to tell anybody.

On the flip side:

Big error reporting system was sorting the displayed list (nice really fast binary search) list into time order every time a new entry was added, the fact that the list was already in time order, and that errors came in in time order seemed to have been missed by the developer. Removing the sort was not optimisation, it was bug fixing, the code was more maintainable, worked as specified, and had adequate performance.

For my mind 'optimisation' is the process of breaking code maintainability for the sake of performance.

Improving the performance, maintainability and efficiency of an application through fixing broken code and improving architecture is a very different beast.