Plotter Directions

There are a number of ways to go

  1. Op-Art: Bridget Riley blocks, moire, etc
  2. “Natural” – textured trees, flower fields, etc
  3. “Glitch” – a more robotic/computerised feel with explicit acknowledgement of the underlying medium
  4. Organic growth abstracts
  5. Textual integration

I’d like to explore the textual side, but it’s hard to bridge the gap between text and drawings, integrating them effectively. I feel like it’s maybe going to be the best to explore though, as the other territory seems to be thoroughly colonised.

One possibility would be to extend the non-line nature of text into collage?

Vaccines – An Excerpt

This the concluding part of a longer essay I wrote a while ago, when sorting out my thoughts on anti-vax. It’s based on “The First Rotavirus Vaccine and the Politics of Acceptable Risk”, Milbank Q. 2012 Jun; 90(2): 278–310.

(Context: there was a “RotaShield” vaccine withdrawn in 1999 following confirmation of a serious adverse event associated with its use with infants. The story around this is an important part of the mythology of anti-vax in respect to one of their prime targets, Paul Offit – one of the most public faces of the scientific consensus that vaccines have no association with autism, among many other things)

The history of the Wyeth/RotaShield vaccine’s approval while Paul Offit was on the ACIP panel is crucial It is at the heart of disagreements around Offit himself, but it also operates as a key part of a negative feedback loop that poisons discussion across the pro-vaccine/vaccine-sceptic divide. I will explain why.

The pro-Offit position is that everyone made decisions around Wyeth/RotaShield in good faith, and that the decisions made remain perfectly understandable based on the evidence available at the time the decisions were made, and that there is no evidence to support the notion that there was wrongdoing involved.

I believe that this position is true.

I simultaneously believe that the ACIP process at the time needed improvements to its conflict-of-interest policy. The very fact that people can accuse Offit over RotaShield in the way they do, in a manner that carries a reasonable degree of credibility to a casual observer, surely proves that there is an issue here. I do not think there is any inconsistency in holding these two beliefs at the same time: you can believe that a COI policy needs improvement, without believing that people in any given situation in fact acted badly.

But Offit’s hard-line critics see a very different picture. They see someone who joined the ACIP panel primarily to enrich himself – using the influence of his position to create a vast and open market for his own (Merck/RotaTeq) vaccine by rushing through the approval of a competitor (Wyeth/RotaShield) vaccine with known safety issues. At its strongest, the narrative is that Offit was fully expecting RotaShield to be withdrawn, leaving the pre-established market wide open just as his own vaccine was available to fill the gap. The consequence of this was the suffering of around 100 children, of which 1 actually died and 50 had to have surgery. In return for this, he has profited to the tune of tens of millions of dollars.

In other words, the essential narrative for many of Offit’s opponents is that he has killed a child for money – that Paul Offit is literally a baby-murderer.

Everything else in people’s views of Offit flows from their interpretation around the RotaShield episode. To call this an “interpretation gap” is a huge understatement: it is a gulf, a chasm. It is impossible to reconcile the views. Offit is a medical researcher who has saved hundreds of lives. He has killed a child for money. He campaigns energetically to save lives in the face of death threats. He schemes endlessly to further his own interests, while children suffer and die as a direct consequence. He is a good man who is doing is best to do good things. He is “the devil’s servant” (

And standing on the other side of the divide is Offit’s dual, the closing half of the feedback loop – Andrew Wakefield. The anti-Offit characterisation is echoed in many of the accusations that are flung at Andrew Wakefield by the more intemperate pro-vaccine parties. Truly, many from each side honestly believe that the other side’s prophet is a baby-murderer. This is such a deeply unpleasant thing to consider that the more decent among those on each side rarely articulate it openly – they don’t even like to call the thought fully to mind – but the thought is there on both sides all the same.

Both Offit and Wakefield give a lot of speeches, but they don’t use this kind of rhetoric directly about their opposite number, and there is a good reason for this. It is a deeply primal, a tremendously powerful thing to accuse someone of being a baby-murderer – there is so much energy to be tapped from the sense of revulsion that results. But it never ends well, because the energy is diseased, tainted at its source. Once you believe someone is a baby-murderer it is hard to even think of them as fully human. Discussion turns ugly even if the underlying accusation is never fully brought to the surface – the unspoken thought poisons everything that it touches, killing respect and goodwill.

More generally, it is healthy for all of us to reject accusations like this wherever they crop up, whoever they are aimed at. No monsters here – only us.

CMY/CMYK pen plotting with Sakura Pigma Microns

This is possibly the most obscure post I will ever write.

Having recently built a “4xidraw” as per Misan’s instructable at I’ve been investigating various uses: I would totally recommend this as a project for anyone into electronics. The accuracy is pretty solid, the speed is good, and the cost a fraction of the “Axidraw” from Evil Mad Scientists – although the “Axidraw” is obviously a far better buy for anyone who wants the machine to get out of the way and just get on with the art bit.

One thing that interested me was the prospect of doing full-colour images, and the “4xidraw” design seems more than capable of overlaying multiple plots in different colours. The theory here is that you combine Cyan, Magenta and Yellow in various combinations – the “CMY” part. If there’s a certain base level shared by all 3, you can draw that out into a “Key” level that is black, giving “CMYK” as the overall name. So by using 3 pens, you can potentially do full-colour designs.

However the pens that many recommend for archival quality plot prints (Sakura Pigma Microns) don’t come in CMY colours. The best we can do is “Blue” (not “Royal Blue”) for “C”, while “M” is “Rose” and “Y” is yellow. The blue, in particular, is way too dark. What to do?

It turns out that with a bit of adjustment, one can rebalance the colour to something pretty acceptable. I arrived at my mix by eye, dong test plots with a small image containing blocks with each of red, green, blue, cyan, magenta, yellow and 50% grey. Note that I only tuned colours in 10% increments. First thing to do was to reduce the “C” (blue, really) in the mix. Setting this at 50% was best – but then “Y” was slightly overpresent. Reducing that to 80% produced the best mix that I was able to come up with using Sakura colours.

I ended up with the following Python code to map from RGB to CMYK. Note that I’m always setting K to zero because, for the kind of plotting I’m doing (“wiggle plots” – where you spiral outwards and wobble back and forth by an amount proportional to the amount of colour), it doesn’t make sense to draw out colour onto a K-layer.

def rgb_cmyk_convert_sakura(r, g, b):
    RGB_SCALE = 255

    # rgb [0,255] -> cmy [0,1]
    # white = no wiggle (0), black = maximum wiggle (1)
    if (r, g, b) == (0, 0, 0):
        # black
        return (1, 1, 1)

    rc = r / RGB_SCALE
    gc = g / RGB_SCALE
    bc = b / RGB_SCALE
    k = 0.0 # we don't use black as this we are calculating for "wiggle" plots: here, using black doesn't make sense
    c = (1 - rc - k) / (1 - k) * 0.5
    m = (1 - gc - k) / (1 - k)
    y = (1 - bc - k) / (1 - k) * 0.8

    return (c, m, y, k)

The results can be seen below. The green of the clown’s body at the bottom right is furthest off – Sakura’s blue doesn’t really have any green in it so we are missing some saturation there. But the match overall is not too shabby.

“Wiggle Plot” rendition using CMY mapping above
Staedler CMY Pigment Liner pens with a “true” (unweighted) mapping – admittedly, far better colour balance!

Green Screen Webcam For £5

Amaze your friends and irritate your work colleagues by setting up your own custom video background to webcam calls for a total outlay of £5!

Commercial software is out there which will attempt to extract your image and replace the background – but it’s (a) expensive to buy and (b) demanding on the processor. Far cheaper to go old-school and use chroma keying – this will enable you to use open source software to replace your background, and seems to run fine on my pre-i3 box which I got off eBay for £50 a few years ago.

1. Get Green Screen Fabric

Search eBay for “green screen fabric”. You should be able to buy 1×1.6m / 3x5ft fabric for around £5 – larger amounts will cost more correspondingly but I managed to get it working with this size.

You can jury-rig a way to hang it behind you (my own solution involves a stepladder, mop pole, g-clamp and 4 large paperclips) or buy a backdrop stand for around £20 more (search eBay for “photography backdrop stand”).

2. Install Open Broadcaster Software

This is free. Go here: Open Broadcaster Software project

3. Install the OBS-VirtualCam Plugin

This is also free. Go here: OBS VirtualCam Plugin

4. Set up ChromaKey output based on your camera feed, and make that available as a virtual camera

The basics:

  • Set up a profile with 3 sources – your webcam, your microphone (for audio) and a media source (which should be below your webcam in the layering order).
  • On the webcam, right-click, pick “Filters” and add “Effect Filter” of “Chroma Key”. You may need to tweak the settings slightly to get a clear image
  • On the media source, set up whatever you want. Don’t worry if it’s wider than the camera.

Some more detailed instructions (the latter includes how to make the output available as a camera):

5. Pick your background

Both static backgrounds and videos are possible by setting them up in OBS.


We’re working our way through Corbyn and many of his supporters not being on board with representative democracy [0]. Makes it kind of tricky to work with the PLP [1]. The end-game is probably a split where you get a representative democracy party and another party based more on Momentum-style direct democracy [2]. One is likely to be a lot more effective than the other at getting things done [3].

[0] representative democracy: you elect a representative and they have autonomy once they are elected, check out Burke etc. So to say that the PLP rebels are acting against the ideals of representative democracy doesn’t really make much sense.

[1] PLP: they tend to be on board with representative democracy since that’s the water they swim in

[2] representative democracy => oligarchy. direct democracy => cults of personality and mob rule. Pays your money and takes your choice.

[3] I’ll bet my money on whichever one is aligned more effectively with the way power works in the UK political system. Which is…

The Glass Bead Game

I read The Glass Bead Game more than half my life ago. It’s about a monastery where the monks are devotees of the aforementioned game, which brings all artistic and scientific endeavour together in a single unified form.

I didn’t like it at the time, and I don’t like it now. I am, at least, clearer on why I don’t like it now, for which I am sure Joseph Knecht would give thanks.

The idea that it is somehow virtuous, somehow positive, to unify diverse fields of endeavour – I don’t buy it.

I have spent much of my working life trying to get people to work more effectively together when tackling problems with a significant analytical content, but a key part of this has always been the acceptance of multiple, irreconcilable viewpoints.

And I love mathematics that makes deep connections between superficially unrelated fields, but maths also has numerous contenders for how one should think about its very foundations (category theory, set theory etc).

“The Glass Bead Game” has the underlying assumption that some kind of global unification of human endeavour is intrinsically a Good Thing. Why would anyone think that?

Conway’s Law’s_law

“organizations which design systems … are constrained to produce designs which are copies of the communication structure of these organizations”

A more generalised statement of Conway’s Law is:

“technological systems and political systems mirror each other”


1) If you try to change the deep structure of technological systems, this will have major political implications. Don’t assume that you can put an information bus or microservices in place as a purely technological fix. The more effective any such change will be, the more of the current political landscape you will be invalidating.

2) More generally, you can’t fix primarily political problems by technological means. If you are getting too far ahead of the political change you wish to effect, you will be pulled back, no matter how good the technology is.

3) You can’t fix primarily technological problems by political means: you can’t make up for the lack of fundamental technology by building coalitions, no matter how well-intentioned everyone is.

Why Liberals Are So Goddam Smug

There’s a recent book out called The Righteous Mind that has an interesting take on how we analyse morality, and how this analysis differs between Liberals and Conservatives. The thesis is that rather than being rational, morality is largely informed by instinctive feelings – and these feelings differ in a significant way between the two political groupings. While both groupings are motivated by considerations of Fairness and Care/Harm Prevention, the Conservatives also refer to notions of Loyalty, Authority and Sanctity/Purity to which the Liberal wing are, on average, tone-deaf to.

One end result being that the Liberals get all aerated about how those dumb Conservatives spend so much energy on stuff that is Obviously Completely Irrelevant because they are So Dumb It Isn’t True (Or Maybe They Are Evil Instead).

The characterisation of Liberal concerns fits me well – the poem “Girls!” by Stevie Smith gets my take on Loyalty and Authority spot-on, and I view notions of Sanctity with the bemused incomprehension of a Martian Anthropologist.

That’s fine and all, but then the question is how a Liberal political movement can hope to engage a stable majority coalition if it’s blind to 60% of the base moral drivers of, say, 50% of the voting population. The answer is that they have to at least be conscious of these drivers and not pretend they don’t exist when framing political issues.


Girls! although I am a woman
I always try to appear human

Unlike Mrs So-and-So whose greatest pride
Is to remain always in the VI Form and not let down the side

Do not sell the pass dear, dont let down the side
That is what this woman said and a lot of balsy stuff beside
(Oh the awful balsy nonsense that this woman cried)

Girls! I will let down the side if I get a chance
And I will sell the pass for a couple of pence

Stevie Smith, from “Mother, What Is Man?” (Cape 1942)

I Am Surrounded By Idiots

…who don’t vaccinate their children. That’s how I feel today anyway, since I am currently a few weeks into the joy of adult-onset Pertussis, more popularly known as “whooping cough” – there is a big uptick in cases in Surrey and South-West London at the moment. Not-entirely-coincidentally, uptake of the Pertussis booster vaccine is very low in at least one London borough, Wandsworth.

However once I get my irritation over my personal circumstances to one side, vaccination uptake is an interesting area.There will always be those convinced that vaccination is the work of the devil, but for the rest of us there are still some deep issues that people need to get past. Some of the issues thrown up in presentations like this:

  • ambiguity or doubts about the reliability of vaccine information, helped by the media “showing balance”
  • a preference for errors of omission over errors of commission
  • instinctive aversion to putting pathogens inside ones child
  • personal acquaintance with someone who thinks vaccines have damaged their child.
  • recognition that if many other children are vaccinated, the risk to unvaccinated children may be lowered

All of these need different strategies to counter:

  • Information could be improved by having a better web presence that was not funded by pharma companies (as part of the problem is distrust of those companies).
  • Omission/commission is an intuitive bias that is hard to counter – obviously not doing something is just as much of a choice as doing something, but this is hard to put across clearly.
  • Instinctive aversion is also hard to counter. A start would be to at least acknowledge that people feel uncomfortable about this, and to explain why they feel this way – rather than to dismiss their feelings out of hand.
  • Personal experience is very powerful. But this can be also used positively, eg by pointing up incidence of vaccination among the health procession.
  • Relying on others to provide herd immunity could be countered by explaining how some people really need others to provide herd immunity, because they are immunocompromised – so relying on herd immunity for a healthy child is re-framed as taking resources from sick people.

And in fairness, it is very easy to see associations where none exist – for instance, when one of my own children had just been vaccinated, they vomited that night. “Aha, side effects” I thought to myself. Then I started vomiting too. As did my other child. Because we all had a stomach bug.

Think I will look for more research in the vaccination uptake field. Once I can stop puking whenever I cough.