Name: Nigel Rantor
Member since: 2000-12-11 16:11:44
Last Login: 2013-08-10 12:13:11



Hacker in the London area looking for cool things to hack on.

Perl rocketh my donkey folks, more like a friend than a language. Java is okay for work but really needs to learn a thing or two from Eiffel, which is pretty tasty as languages go but needs to get it's act together in terms of popularity unlike Ruby which is absolutely wonderful and gaining converts all the time. Still haven't tried Python but I think that may be because of the whole indentation police issue.

I have decided to take the plunge and try to get a pure-Perl CORBA implementation up and running. If anyone is interested or knows anyone who would be willing to sponsor/employ me to do this then drop me a line. (yeah, I know, right...)

You can get me on

echo -n | tr a-z n-za-m
(and thanks to whomever's diary I saw this on. I hope it will stop some amount of spam.)


Recent blog entries by wiggly

26 Sep 2003 (updated 26 Sep 2003 at 12:58 UTC) »

On the subject of solar energy.

I am not an engineer or physicist but I know some basics so I'm not claiming to know everything here but just hear me out.

Let me firstly restate your idea in bullet form.

  • Place water in a vacuum sealed container.
  • Create partial vacuum to lower pressure.
  • Direct sunlight onto water vessel to heat it.
  • Since the pressure is now lower than normal the water boils at less than 100C.
  • Water vapour is directed to turbine to generate electricity.
  • Waste water recycled into cool vessel for reuse.

The problem as I see it is that your setup as described is self-defeating.

Firstly it will take energy to create the partial vacuum to decrease the pressure in the enclosed vessel. So you already have to create more energy than this for the system to generate a surplus of electricity.

Secondly if you lower the pressure to make the water boil at a lower temperature then you wouldn't be able to use the vapour to power a turbine. As soon as the water vapourises the pressure in the enclosed vessel increases and the vacuum pump will be working to draw it out of the vessel to maintain a lower pressure.

If you turn the vacuum pump off after creating a partial vacuum then the pressure will rise until the boiling point of the water is back at, or above, 100C.

Basically the vacuum pump renders the turbine inoperative because the turbine requires a positive pressure to move it, and therefore generate electricity. Whilst the vacuum pump is generating a negative pressure, and also using up electricity.


Wow, that sounds bad.

Since it sounds like you have pretty good access at your hosting provider how about a short-term fix?

You could use procmail and a list of email addresses to generate a whitelist program that will only let sender's you know to get through?

I was going to e-mail you but I figured you might not actually get it.

Also, I'm in the market for a good hosting provider so any and all suggestions to my e-mail address on my page please...points will be given for db access, custom perl libs, dns admin, good e-mail setup, IMAP servers blah blah blah...

20 Aug 2003 (updated 10 Aug 2013 at 11:48 UTC) »

I agree. There is a lot of non-technical musing floating about here. Thats not a bad thing except this is a site devoted to technical matters.

I can't say I'm bothered enough to really do anything about it though, maybe I haven't been here long enough to find it a problem.

Yes, articles are few and far between. However not everyone can post articles...


I'm not a PHP person and I don't know enough (or couldn't guess from your description) about your system to really say but here are a couple of thoughts.

It sounds like you might look into memoisation for your 'tags'. If these are functions that will be called multiple times with the same arguments then memoisation might give you a good boost. Not sure if there is a PHP module for this . Have a look here for a short definition - memo function

Basically a memo function is one where the system caches previous calls to the function. When the function is called the system checks to see if the function has already been called with these arguments and if so simply returns the cached result.

If you wanna have a chat e-mail me, my address is on my Wiggly page.


Cheers for the tip on Catmull-Rom splines. Have been playing around whilst I should be sleeping and I have now got some code plotting nicer looking maps. The code needs a lot of cleaning up though.

Now I need to figure out a good way of getting it to automatically figure out which lines are legal since there are some routes that from a simple 'station A connects to station B' approach can't take into account. I may have to add some more information to the data model that can be used to determine this.

Also, the code that produces a set of points to put into the Catmull-Rom plot needs to take loops into account, currently I'm using a simple recursive function to figure out the set of lines that need plotting starting from terminal stations.

London Tube

Hmm, well I've been looking into how to make bezier curves to connect up the stations but there are a few things that I can't quite work out in my head yet. (quite possibly I just need to do some experiments but the weather over here is forcing me to visit the park)

So, one idea is to create a bezier between three stations, using the middle station as the control point. The problem I can see with this is that when this is done for all of the stations that the lines will probably not join up to form a smooth spline.

This leads me to think that maybe I need to connect every point in the line and use every station but the first and last as control points but figuring out an entire line in the london underground could be quite tricky programmaticaly. And I'm not even sure it would work either.

If anyone has experience with this kind of thing then I'd welcome any ideas. Maybe I need to do some more research into graphics (never done any) to find a different algorithm for creating smooth splines between points.


London is pretty much baking, lucky I don't mind the heat I guess.

chromatic in some ways I agree with your view of not using XML for configuration files. If I have simple data then I don't. If I have a simple set of data then I would just go and use AppConfig or some other equivalent.

However when you have highly structured data it becomes a really difficult proposition to make the config files readable anyway since you may want to make it refer to itself in some way, or have some arbitrary nesting of configuration options.

So, out of interest, do you think you should never under any circumstances use XML for configuration files? Or what?

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