Programming .walk for Dummies

- Posted: 24.Jan.2006.

THE TECHNOLOGY WILL FIND USES FOR THE STREET ON IT'S OWN

programming .walk for dummies

Example 1

// Classic.walk Repeat { 1 st street left 2 nd street right 2 nd street left }

This .walk example shows the classic generative psychogeographical algorithm, that urban exploration haiku, written down like a pseudo-computer language .

Example 2

// T = Time (in minutes) // E = Exportcode // C = Counter E = 2 C = 0 Repeat { X = E 1 st street left 2 nd street right X street left When 2 agents meet { Exchange E C + 1 } Count T 0 to 60 If time = 60 { Abort to Root Print C to socialfiction.org } }

Or in straightforward English:

"Your export code is 2
Repeat the following instructions; walk the first street left, second street right, then you take the street left that is indicated as your export code. Every time you meet another psychogeographer you exchange export codes. This new code will change the 3rth turn.
Remember how often you exchange export code.
When you have walked for one hour you return to the place your are supposed to meet.
Once arrived there report the number of encounters to socialfiction.org."

For this simple talk this would do just as well. But when, like in the examples coming up next, the functions the applet will have to perform are getting more complicated a verbal explanation will require a lot more text of a very dense nature as the instructions must be interpretable in one way only. Symbolic logic serves the purpose of single minded communication much better than any natural language.

All the action happens between the { } after the Repeat command. Also notice that in this applet individual agents participating in an experiment are connected through the exchange of their E (Export code). This is a feature that was not available in the first example but without which it would be impossible to design a psychogeographical computer: an interconnected bunch of small applets, called .walk software (or if you like walkware) that runs (or rather walks) on top of the hardware, the street grid.

Example 3

// Fibonacci .walk // 1, 1, 2, 3, 5, 8, 13, 21, 34, ... Z = 1 Z(x) = 0 Repeat { Z Left or right {random} Z(y) = Z Z = Z + Z(x) Z(x) = Z(y) }

In example 3 we start to see the power of writing down the rules for algorithmic walks in symbolized rather than plain English.
This applets differs considerably from the 2 examples above;
First: there is no succession of turns, there is only one turn that can be left or right that because of the {random} command can be chosen by the agent.
So when Z(x) = 5 the psychogeographer enters the fifth street. When this street happens to be at a crossing with both options available take the one you like.
Second: this applet computes it's own next turn. In example 3 this happens according to the Fibonacci number series.
This series is infinite & following this .walk applet to it's logical conclusions must soon becomes surrealistic, if not downright absurd.

Example 4

// Divide.walk // 8/2 // C = Counter A = 8 B = 2 C = 0 E = B Repeat { If E = A { Abort Print C to socialfiction.org } C = (C+1) C street left or right {random} E = (E+B) }

Everybody knows by heart that 8 divided by 2 gives 4, but only Slashdot creeps can divide 19 by 6 from the top of their head & come up with the correct answer of 3,1666... With the applet in the next example you can just do this kind of calculations. This does mean the introduction of decimals.

In example 4, C (counter) counts the times it take to divide a number, that is the answer to the problem 8/2, C also determines the next turn. Every variable could be used to determine this, but using the counter makes this count easier to remember especially when the outcome becomes higher this might be handy.

Example 5

// Divide.walk // 19/6 // C = Counter A = 19 B = 6 C = 0 Cdiv = 0 Q = 1 E = B Turn_X = 0 Repeat { If E > A { E = (E-B) A = (A-E) A = (A*10) Q = (Q*10) E = B Turn_X = 0 } Cdiv = 1/Q C = (C+Cdiv) Turn_X = Turn_X + (Cdiv*Q) If E = A { Abort Print C to socialfiction.org } Turn_X street left or right {random} E = (E+B) }

The walk in this case means taking sequences of turns, first the 1st to the 3rd left or right, then the first left or right, then infinite clusters of the 1st to the 6th turn left or right. The comma is always behind the first cluster.

Remember that the syntax of these .walk is not fixed. Applets can be written in any way, can mimic any known computer language. It would be worthwhile to think of a way of formulating statements/rules that don't resemble the languages used in the ordinary computer world, this would stress that .walk is not merely an offshoot of something that is already existing but that it is a whole new field of research.

This last applet shows how pedestrian activity can be made to function as a non electrical computer, able to perform difficult calculations while the agent walking it doesn't need any mathematical skill at all. .Walk is not only meant to platform independent it should also be designed in such a way that everybody can execute any applet.
At the same time the walkware is still producing non-intuitive routes for urban exploration that is it's main function. By connecting different applets, all executing their own rules, doing computations in the meantime, a giant psychogeographical computer emerges.

The first experiments in executing .walk software were done with variations on example 2. The main goal was to find out the frequency of agents crossing paths during an experiment.
The higher the frequency the easier data generated by the individual agents are spread through the network, this adds speed to the processing power which is in itself correlated to the number of agents involved at any given time.
The pace of the psychogeographers is another crucial factor in the speed of calculations.
From past experiments it has been determined that with small groups (8 simultaneous applets active in Rotterdam [Nov. 2002], 6 in Londen [Dec 2002]) the number of encounters that take place in one hour are rather low: only once twice, often only once & just as often no encounters at all take place. This calls for separate .walk applets that don't compute anything themselves but gather & transfer data through the different nodes of the Psychogeographical Computer. This might be done by giving them rules that are responding to the movement of the other agents. Because past experiments showed that generative psychogeographical walks doesn't result in crossing enormous distances, but rather a circular movement around an schizoid sort of imaginary axis, these agents might employ the tactic of patience to locate the others.

From here .walk can be used to construct walkware like peripatetic databases, psychogeographical artificial memory, or .walked calculations can be fed to software that renders visuals, sound or behaviour.