______                     
                 /      |       ________     
                /       |____  /        \    
               /        |    \/   _      \   
               \       ___       /_\      \  
                \      \_/          .      \ 
                 \          /\_____/       / 
                  \________/      |       /  
                                  |______/   

[THE_EXPR_METHOD] 003 sequencing

Apart from the discrete changes in values, generating control signals for sequencing, can be approached just the same way as that for modulation. That is to say, one essentially find ways to “alter” the appearance of a given waveform so that a “stepped” version of it emerges as a result. Transforming a signal from continuously and smoothly changing to being quantised and value-restricted is therefore the objective when preparing control signals for sequencing.

The following quick example will produce a sawtooth signal that contains 10 distinct steps within its wave cycle.

[phasor~ 1]->[expr~ floor($v1*10, 0)/10]

Because a quantised signal holds the same value temporarily until the next element comes along, by using comparison operators (“equals for example”), it becomes possible to isolate/select a certain portion of the sequence. Since the comparative statements will return true for the entire duration of given time “step”, it thus allow for further (differential) treatments to the signal that falls on either side of the test. This property of the sequencing signal might initially seem trivial, but it makes such a signal very useful in solving many of the tasks that are commonly faced when dealing with time dependent structures.

The following example demonstrates how one can select the last element in the sequence of 4 incremental counts (0,1,2,3,0,1,2,3…), and subsquently reassign its output value (0,1,2,0,0,1,2,0…).

[phasor~ 1]->[expr~ floor($v1*4, 0)]->[expr~ if($v1 == 3, 0, $v1)]

Combining with relational tests, control signal for sequencing can extend far beyond as being a simple counting mechanism. Many common objects such as [select], [spigot], [int] and [moses] can all be emulated easily. Dynamic signal routing and flexiable looping are other examples that are relatively uncomplicated to implement.

The exmple below demonstrates an interesting way of counting by utilising the modulo function.

Get the source here

Exercise:

What other arithmetic functions can be used to modify the control signal?

Which other parts of the example patch can be modulated/sequenced?