Freesteel

The power of letting python call OpenGL directly. I thought it wasn’t practicable, but it seems to be okay. Here I’m testing out the toolholder collision detection; showing a series of points where the cutter gets lifted to when there is a wide conical tool-holder in place.

The colour is according to how long the calculation takes (red for slower). It varies by where the sample is taken and will help tune where I need to make the speed improvements.

I’m working today. But there is time between compilations of code. I avoided surfing the internet onto anything democracy-related, because then I’d've got lost in something interesting and would still be at it at 3am. No chance of that happening when you restrict yourself to the webpages of CADCAM companies.

It’s good to see some of them realizing that the correct format for showing off machining features is the video. Although the quality and content — let alone the lack of sound — is very poor, Delcam has produced a selection to be getting started with. The top one repeatedly shows their user interface interchanging between loops or blobs as it area clearing path goes around corners. Now I know they’ve got a whole machine shop in their building, so why don’t we see how it cuts metal?

MasterCAM has a much better set of videos, although the user interface to them is questionable, and the image is too big. They do give narration and fade nicely between the scenes. Choose Peel Mill in the selection of videos to find a description of their limited trachoidal milling solution, otherwise only mentioned in this press release.

Obviously, both companies haven’t yet reached the state of the art for horizontal trachoidal machining embodied in our four-year-old Adaptive Clearing strategy. If they want to save a lot of time and hassle developing it, they only need to ask. Our rates have been quite reasonable.

WorkNC has 3 videos showing their old Adaptive Trachoidal Roughing. This looks like a retrofit of trachoidalism on a standard offset area clearing algorithm, truncated in the case of a core. At least, like the MasterCAM feature, it shows the capability of this way of machining deeply and cutting with the side of the tool.

I’ve checked out cimatron, solidcam, Tebis, esprit, vero, edgecam, and what became of nc graphics, and none of them seem to have any videos.

There are some on surfware, but the funny thing about it is you can find a far better video of surfcam on youtube, because it’s got music. Just say No to that grinding metal noise. OncCNC has some videos too.

Here is a video of Adaptive Clearing in graphite. And here is a page on HSMWorks where they tell you about Netviewer — a programme that allows someone in Denmark to demo the software remotely on your computer. Why not video one of those demonstrations to make it easier to show up?

Sometimes the campaign managers need their heads banging together.

I haven’t forgotten the time that Tom Watson MP was sent packing after smearing a LibDem candidate for being “soft on criminals and drugs” for having been employed as a barrister and represented such clients in court in her legal capacity.

Politicians, many of whom have worked in the legal system, knew this was totally unfair because (a) all criminals are entitled to legal representation, and (b) barristers are obliged to take the cases given to them.

And so we come to this press release which appeared yesterday at http://www.creweandnantwichlabour.org.uk/get_the_yobs, which they probably think is fair:

Edward Timpson simply hasn’t got what it takes to make our streets safer and stand up for people in Crewe and Nantwich.

DID YOU KNOW THAT EDWARD TIMPSON’S TORIES HAVE:

Opposed tougher sentences for dangerous sex offenders.

Opposed 5 year minimum sentences for unauthorised possesion of a gun.

Opposed more powers to crack down on underage drinking.

Local residents are saying they want someone with a track record of action getting tough on yobs to represent them – not some Tory Boy who clearly isn’t up to the job.

It is not good enough to just talk about getting tough on crime, the people of Crewe and Nantwich deserve action.

Tamsin Dunwoody knows what is takes to make our streets safer. She has come forward with a plan of action to cut crime and crackdown on anti-social behaviour. Tamsin Dunwoody wants the police to harass yobs, and get in their faces.

She said: “There’s a lot of talk about human rights, for me the most important human right is to feel safe in your home and community.”

Crewe and Nantwich need a fighter who bangs heads together and gets things done.

Tamsin Dunwoody will always stand up for you and your family, she’s a Dunwoody after all.

Now, there’s no email on the site, and they probably wouldn’t answer my requests for particulars. But the source of the allegation is crucial in order to verify the interpretation.

After all, while LibDems can be branded as woolly-minded and soft on crime (according to brain dead wisdom), it seems peculiar to argue that Tories would refrain from the concept of locking people up and throwing away the key — in cases where that would be a good idea.

You’re supposed to count on the designated right wing party to demand punishments for violent crime on the more extreme side of reasonableness, so to call for something that goes beyond their policies is probably going to be unreasonable.

Therefore, such a one-line allegation that Tories are not being tough enough on crime shouldn’t even hold water.

And anyway, it might not even be their policy, because the evidence could be completely circumstantial.

So, to the particulars. There’s a 22 January 2004 press release by the Home Office: Crime Remains Stable - New Five Year Minimum Gun Sentence.

This is a good start. It leads me to the Criminal Justice Act 2003, more specifically Section 287 of the Criminal Justice Act 2003.

Really handy that. It looks like it was thrown in with this raft of measures as New Clause 46. The vote on that raft is here, and the Tories in fact abstained. If you read the debate, it just seems like chaos, with all the debates truncated, and it just doesn’t look good. Anyways, there’s a very strong case against minimum sentencing, which obviously went over the head of our berzerk Home Secretary David Blunkett at the time.

We are talking about such cases as multiple and sadistic killings, and when terrorists take the lives of others. In more traditional terms, before suicide bombing occurred, there was at least a way of sending signals to and getting retribution from terrorists. We are talking about incidents of child murder, which I have described, and the way in which people abused others before committing such a crime…

I am motivated, as is indicated by the sentencing framework and the new purposes of sentencing, by the desire to show those who are engaged in such actions that there will be clear and unequivocal consequences.

What a mess. There’s no evidence that harsh publishment reduces crime. It’s an ill-informed and ignorant thing to believe, and highly irresponsibly to use a position of authority to tell people it’s true.

I just don’t want to think that this was done for the benefit of one line in an election leaflet, and that there’s a whole tranche of other misleading crap stored up waiting to be shovelled out onto the pages of all the campaign materials. It shouldn’t be done. And more importantly, it shouldn’t succeed. If this was London or Edinburgh, they’d probably be throwing around the “T” word for good measure.

Press Release – Immediate Release
14 May 2008
The Public Whip

While activists are descending from all corners of the country to Crewe & Nantwich to help with their partys’ by-election campaigns, volunteers from the Public Whip today launched an online questionnaire to help people make up their minds about who to vote for. The webpage:

http://www.publicwhip.org.uk/byelection

compares people’s opinions to the way each party has voted in Parliament on a selection of important issues that have been in the news in the last five years. It uses the web-site www.theyworkforyou.com as a source of data.

As Julian Todd of Public Whip explained “An election is the one time people have a direct say in what the politicians do. Unfortunately, with slick sound-bites and colourful leaflets focussing on one or two key points, it’s easy to forget the bigger issues that will be decided by the MP who eventually wins the seat.”

Aidan McGuire said “The national issues which our MPs have control over are not being discussed with the candidates during this campaign. People are easily distracted by smaller matters like car parking charges, when what is actually decided by those who are elected include compulsory ID Cards, nuclear power plants, freedom of information laws, and the strategic supply of fuel and electricity.”

“We want people to remember the bigger issues and ask hard questions of the candidates about how they would vote after they are elected. People have become used to not being told what the policies are and not insisting on their right to know.”

Here in Crewe & Nantwich, the Labour candidate, Tamsin Dunwoody, is running on her mother’s name. Gwyneth Dunwoody was a popular MP partly because she had a mind of her own and did not vote the government line on every issue. How many people have looked up which were the issues she rebelled on, and has anyone asked Tamsin whether she would take the same position on those issues?

Julian said: “We want people to start using the internet more effectively to understand what their MPs are doing and to keep a close watch. Who knows, they might start doing more of what people want them to do, rather than their own thing all the time. That’s our idea of what democracy would look like.

“That’s why we’ve brought the Public Whip website to the voters of this city. It’s our tiny contribution to democracy. We hope to inspire other people with our example so they bring their own democracy projects to places where it matters, like this by-election and other elections in the future, to help voters make an informed choice. Democracy is too important to be left to the political parties alone.

About the Public Whip
Public Whip is a website that scans Hansard, the official Parliamentary record, for all the votes by MPs and sorts them into a database for further analysis. It was originally written by Francis Irving and Julian Todd in 2003. All the software is free and open source and is completely self-funded and maintained by volunteer work.

ENDS

The leaflet has now been passed in front of a few sharp eyes. I’ve got to recheck all the numbers on it before I take it to the printers.

We do things properly around here. I’m emailing all the candidates campaign emails with a copy of the leaflet, asking for any comments, and stating my interest as a recent member of the Green Party, for which I will be doing no campaigning.

The Labour candidate webpage is up. Have emailed them through their crappy webform which required me to give my postcode.

I’d already emailed UKIP and given them an earlier copy. They told me I couldn’t use Bob Spink’s voting record as a basis for UKIP, so I deleted the column in the table, which is fine by me as it freed up space. I tried. They didn’t bite.

I don’t feel like contacting the English Democrats.

I’ve emailed a copy to the LibDem campaign. I happen to know somebody whose wife is going down on Friday to help them campaign. He asked if she could take a copy. But I am being strictly non-partisan here. If she reaches their office and tells them not to bin my email — as all the other candidates are most likely going to do — they’ll have the advantage. Such as it is. Interestingly, when I take the test on the webpage the LibDems score 128/140, the Tories get 59/140, and Labour gets 38/140. So it could only go downhill from that.

I really can’t face emailing Mr. Cut Tax on Petrol and Diesel.

No need to email the Greens. They know who I am, and I happen to know the candidate who was an emergency last-minute parachute from Liverpool. It’s chaos out there. I will get someone in the Party to make me a voting chart for the Public Whip to stand in place of their lack of MPs if it is the last thing I ever do.

Now to print out some maps. We go away to some geology course in North Wales over the weekend. Then back to this game.

I know, why not catch the train down to Crewe where there is a by-election and deliver this leaflet to 5,000 doors.

More time wikipedia-ing UN information. I dipped into a recent Security Council transcripts where there is a satisfying whinge from the ambassador of Costa Rica about just what a stitch-up these resolutions are among the “Group of Friends” (their code name for the Permanent Five):

It is especially difficult for Costa Rica to understand the opposition to including a reference to the human rights component in the text of the draft resolution. During the negotiation process, we proposed two options for incorporating such a reference. Today, to our surprise, the representative of the Russian Federation threatened to exercise a technical veto of any reference to human rights, despite the fact that the issue of human rights is the object of mutual accusations made by both parties, that it has been raised in consultations by various delegations, and that several references are made to it in the reports of the Secretary-General. In his most recent report, Secretary-General Ban Ki-moon himself refers to the United Nations duty to uphold human rights standards in all its operations, including in Western Sahara, and to the need to coordinate action in that sphere.

Costa Rica cannot understand the reasons that have been put forward for rejecting a specific reference to the framework of international law when we are calling on the parties to assume a realistic position in the negotiations, nor do we understand the fact that the Group of Friends should sideline the members of the Security Council in the preparation of the texts of draft resolutions and in the building of consensus. In this case, just a week ago the Group of Friends provided us with the text on which we are about to vote and in which my delegation continued to insist that some of its amendments be included.

I did far too much digging back and this incident boiled down to one line in the Wikipedia MINURSO page. The problem is that all the resolutions relating to the UN intervention in Western Sahara appear to tilt towards the Moroccan government, and are cleansed of all references to human rights, which means that the UN is blocked from doing anything about it. So to the outside world they look incompetant, when they are merely working in a framework set out by the major five nuclear armed states (the Permanent Five). I’d like the citizens of those countries to know that.

Also, all the code has been moved to be under the GNU Affero General Public License, due to the recognition that the General Public License is practically obsolete in relation to server side software which you can interact with on someone else’s computer through the all-pervasive internet, yet not have any access to the source code of because you never touch the compiled code.

Also, the General Assembly is finally publishing some post-December transcripts. I hadn’t noticed because the parser ran cleanly without an error.

There’s an astonishing number of Liverpool local elections wikipedia pages set up by administrators, which need investigating.

Yesterday we got up at 4:45am, and Becka pulled me out of the house at 4:52am having had no morning tea and forgetting to put a banana into my pocket for breakfast. Things were already busy over at John Coyne’s house in St Michael’s Ward where everyone had converged to do the early morning mail drop. Coyne had printed out a handful of personalized letters to certain addresses urging residents to vote Green, and we also had these very dull little post-cards to post through the doors of all the others.

I bagsied Floral Wood and surrounds because I’d found its spread-out American-style pavement-free suburban mock-tudor architecture stunning when I leafletted the area earlier in the week. These houses had enough room to park all their cars at once, which is important because the only way to the doors without stepping on the grass was up the driveway. I couldn’t understand why they don’t have swimming pools out the back as well.

In the other streets, such as Westward View or Thistledown Close, people don’t have space to fit their regulation three cars and no bike, so you’re constantly having to walk round the sparkly BMW on the pavement. I hope to live long enough to see the automobile age end and these proud beasts go to the crusher. In the long run, all of the Green policies will be adopted by society, in the same sense that whale hunting has ended. The only question that matters is whether it stops before or after the whales (or we) become extinct.

The sun gradually rose. The milkman came and went. I saw the LibDem guy doing his morning leaflet drop — it was a big yellow A4 piece of paper shouting: “Good morning!” on every doormat beneath the letterboxes in the porches. I taunted him with the stiffness of my Green Party postcards that were strong and durable enough to push through the bristles behind the letter flaps if you applied just the right amount of longitudinal curl when you did so.

Letterslots! Now that’s a major case of User Interface design satisfying the common criteria of an obvious problem which could be solved if only the person who had the power to do something about would ever happen to notice. You can own a house for 20 years and never once in all that time experience what it is like to push a thin envelope through your own letter-slot! I can push the over-sprung flap inwards with my left hand, but, unless I aimed exactly right for the gap between the thick black brushes, it crumpled. Some places have an extra inner flap on the other side — with an inward hooked lip!. What kind of &*@%#~?!!! You have to insert your entire left hand in to get it through. Luckily there was no dog on the other side. The other mind-bogglingly stupid type of letter slot is the kind that’s vertical and hinges upwards instead of sideways. And, while we’re at it, why is it legal to sell front doors where the slot is 5cm above ground level?

We got home, did our other stuff, then got our tickets to go to the count because Becka was a candidate and I was an invitee.

It was a fantastic experience!

I had expected to be sitting in a waiting room while the technical counting staff did their work a safe distance away, until the boring announcements made by a boring person at 3am in the morning told us of our fate.

But it was nothing like that. Instead we had free reign to mill around a huge sports hall where the tables were laid out in areas according to the wards of the city. The ballots were counted right there in front of you in the open. You could lean over and point to them.

There was a huge crowd of Greens over at the St Michael’s Ward desk (all the Green candidates who’s names were put up in the other wards were there), some with clipboards making their own tally as each ballot sheet was unfolded and flattened out into a stack. This was the first stage in the counting process.

Becka and I drifted off so as not to put too much pressure on the counting people. At the other side of the hall we found the BNP dudes hovering over the desk for Belle Vale looking like typecast characters selected for a play. Two of them were even wearing blazers, one with war medals — and he was probably less than 30. I felt intimidated until I saw the Labour Party leader, Joe Anderson, nearby. He out-thugs anyone by appearance. The last time we crossed paths was when Condoleeza Rice visited Liverpool and I was part of the crowd shouting at him not to go in to watch the show put on in her bloodthirsty honour.

Without doubt, the desk I felt most sorry for was for Allerton & Hunts Cross where Flo Clucas presided like a stern pensioner watching her pound notes being counted out at the Post Office.

Kirkdale had this complicated double-length ballot sheet because there were two seats and you could put a cross in two places. What they did to count this is too complicated to explain.

Back at Princes Park where Becka was a candidate, the sharply dressed Labour candidate Timothy Moore (seems to be no picture available on the web) was having kittens. The local MP Louise Ellman was at his side. Later in the evening when his seat was secure, they got a bit chattier. Of course she recognizes me. And of course local MPs always show up for these counts — they depend on these party activists when it’s their turn to be elected.

After unfolding and flattening all the ballot papers, they’re sorted into piles. This stage is done across the desk so the piles are on our nearside (their farside) and we can see that they are being put into the correct places. There’s a tray for spoilt ballots (eg “no - faith - in - any - of - you” written down the column).

After this, the piles are bundled up into batches of fifty and given a colour coded piece of paper according to the candidate. Now the amounts are easy to see, like bricks of hundred dollar bills in a businessman’s suitcase.

Our Green candidate, Sarah Jennings, won her seat. She’d been canvassing solidly since January and has attended every Liverpool City Council meeting in the public gallery for a year, so the system works to some extent. Though I do have a lot of unanswered questions about voting behavoir and what really drives it on.

As the most interesting individual result, Sarah was interviewed several times by earnest young reporters who took notes in shorthand. One of the main Green Party organizers, Peter Cranie, was always at her side to help with the questions. We clustered in a group to cheer for the cameras when the result was officially read out. Someone gave her forms to fill in relating to the acceptance of the position of city councillor.

Becka and I sloped off at 1:30am on our bikes, the only ones in the whole of the carpark. It’s was an experience of hope and joy. An antidote, and proof positive that it’s possible, and totally desirable, for elections to be counted with complete fairness and transparency — unlike the misery they experience across the pond in the greatest democracy in the world.

It also explains why the idea of electronic voting has never been an issue in the United Kingdom — in spite of the fact that the UK political class are demonstrably more ignorant than anyone else about what can and cannot be effectively computerized; while several other European countries with better informed elites have completely fallen for it.

Electronic voting is off the table in this country, not because it is hugely expensive, woefully unreliable, and vulnerable to fraud in an unbelievable number of ways — all points in its favour for the people in charge, since it’s not their money or votes that get ripped off!

No, electronic voting is off the table because it would take away the thrill provided by this absolutely perfected proper paper count process.

At present, no one is sure how the balance of power has shifted. And I don’t really care.

The Audit Commission report from February 2008 says that Liverpool is the worst financially managed council in the country and that (p8):

Member behaviour at times is poor and affecting capacity. There has been inappropriate behaviour dealing with some officer issues. Information is sometimes ‘leaked’ to the press and other sources for short-term political advantage. Behaviour of some members at Council meetings is poor with personally abusive language used and aggressive behaviour regularly demonstrated. As a result, some members said that they would not speak at a Council meeting for fear of being shouted at or ridiculed. Trust between officers and members is not effective. Members recognise that the culture of the organisation is not appropriate and stated that the culture needed to change. Behaviour of some members is damaging the reputation of the Council which is recognised by all members.

Shame they don’t stick it on television, like they do Parliament. Couldn’t be any worse.

I was reminded that the late Frank Zappa was right when he told kids:

“… and I’ve been telling kids for quite some time, is first register to vote, and second, as soon as you’re old enough, run for something.”

With this glow of positiveness, the question now more than ever is how does it get so bad from here? Where exactly does it go wrong?

It’s critical to be able to calculate the orientation of a triangle correctly, particularly if it’s the long thin kind where the endpoints differ by 1e-15 in the y direction. The orientation is either clockwise or anticlockwise, and it should be the same no matter which of the three vertices you start with.

For a triangle with points a, b and c, we consider the vectors u = b - a and v = c - a. If

CPerp(u) . v

is positive, then the triangle is oriented clockwise, where CPerp((x,y)) = (y, -x) is the function that turns a 2-dimensional vector 90 degrees clockwise.

Writing this in individual coordinates gives:

CPerp(b - a) . (c - a)
    = (b_y - a_y, a_x - b_x) . (c_x - a_x, c_y - a_y)
    = (b_y - a_y) (c_x - a_x) + (a_x - b_x) (c_y - a_y)

which you can either expand out into 8 terms (two of which are ±a_ya_x which cancel immediately) and add them up, or you can evaluate them as they stand. You can get different answers; sometimes one is zero and the other is non-zero, and since the sign of the result determins the orientation of the triangle, we pick the non-zero answer.

To reduce loss of precision, sumations are done from large to small; after putting the six terms into the array double s[6];I write:

sort(s, s + 6, FabsOrder());
double sum = (((((s[5] + s[4]) + s[3]) + s[2]) + s[1]) + s[0]);

where

struct FabsOrder {
bool operator()(double a, double b)
{ return fabs(a) < fabs(b); } };

That’s the C++ done with. Now the problem. There was a conflict in the sign between one value and the other which was highlighted by the debug code, but, because it seemed infinitesimally small and we’d forgotten the significance, we commented it out and encountered a situation much later in the algorithm where there was a gouge that took a while to isolate.

The calculation problem.

In the above equation, if b_y = c_y, then the the alternative ways to calculate the result are given by the two sides of the equation:

p (r - s) - q (r - s) = p r - p s - q r + q s

And if r - s is positive, then the result should be positive whenever p > q

But here’s a table of calculations that happens.

Now I had been counting on the right hand column to be increasing, because 13.014700000000001 - 13.014699999999999 > 0, but unfortunately it does not. This explains how I can get the wrong sign in the answer, rather than 0.0 when the precision falls off the end, because I am taking the difference of two values where s is increasing in the expectation that the difference of the products will increase too.

This has been a day’s work. I’ve marked this down as yet another of many things to watch out for with floating point arithmetic.

Meanwhile, after scratching my head all day over this problem, the BBC reported that some computer keyboards are dirtier than a toilet seat. If I saw a toilet seat as grubby as this keyboard is now, I wouldn’t sit on it.

I’ve spent the past two days leafleting for the Liverpool Green Party, both in the target seat of St Michael’s, and in Princes Park, the ward in which Becka is a paper candidate.

There are three councillors per ward, a term of three years, and an election for one of them each year. (Correction: The term is four years and one year out without an election.) This maintains continuity, as well as maximizing the chance of a hung council as the balance of power shifts from one party to another through a continuum.

While leafleting in St Michael’s ward I got harangued quite loudly in the middle of Lark Lane by a big white guy outside of his pub where he was smoking because I couldn’t be specific about the paragraph in the leaflet:

Greens will demand progress on broken promises to deal with Lark Lane traffic and to create a special planning policy controlling bars and restaurants.

“What are you delivering this sh*t when you don’t even know what it means, you prick!!!”

I sought clarification when I dropped the spare leaflets back at base. The rule is that planning applications have to be considered individually on their own merits, unless an area has been declared special, in which case the fact that there are already 14 noisy bars along a 90metre row of buildings may be taken into consideration when the application for the 15th is considered. Now I know.

The Princes Park ward, in which Becka is a candidate, is not a target seat and there’s no chance of winning (hopefully). But it’s necessary to put someone there or people who would like to vote Green don’t have an option. On looking up the election results in 2006 and 2007 I’d noticed that it came to 9% and 14% respectively. Somewhat surprisingly large, I thought. We wrote up a fairly incomprehensible leaflet last night, put Becka’s photo on it, got 500 copies printed this morning, and spread them about the place. (Okay, in the posh areas that were close to home and not frightening to deliver in.)

Last week the Labour council candidate came canvassing through here at Martin’s house on Cairn’s Street with Louise Ellman MP in tow. Martin sent them packing, but I ran out across the street a few minutes later with a laptop to show them my publicwhip voting quiz in preparation for the next General Election. They’re not going to forget about that.

Louise Ellman, you see, is the inspiration for the whole Publicwhip project with her vote cast in favour of the Iraq war. I wanted to be sure that we could keep history alive, so that as that entire unnecessary debacle sinks deeper into an abject catastrophe, we never forget how we got here: by stupidity, bad judgment, a culture of violence, and a political system that rewards all of the above.

The software behind Publicwhip contributed to the great TheyWorkForYou.com, and Louise Ellman’s website is probably the only MP’s site that makes no reference to it. Perhaps she thinks it’ll go away if she ignores it.

Anyways, we delivered lots of leaflets, and there was one resident who said she was not going to vote for anyone because last night a young lad was beaten up and hospitalized by a gang of youths when he was minding his own business walking through “their patch”. They’re always intimidating white people there.

Having worked in a house in the street one block away and commuted to and from it twice daily (by bike), I can’t say I’ve noticed the issue. Still, it’s the sort of thing the police are good at dealing with, and they may have a more complete story.

Incidents of assault would be an ideal geo-located data stream to add to the Metroscope. In my life, the only place I have really properly been assaulted is in Cambridge City centre, literally yards away from patrolling police. In my opinion, age, gender, and how pissed someone is are the deciding factors for whether he is likely to beat someone up for no reason. Otherwise the assault is generally about money, debt collection, or the control of a captive market.

I couldn’t find any trace of the incident on the Merseyside Police website. However, under the list of air-support incidents for April 08, I found this case:

With data like this, I must make more time for my Metroscope work.