UGen Sieve1 undestanding

Questions
1

Hi,
Is there any chance to know more about the parameters of the Ugen Sieve1 and the formula(s) under the hood?
I know the idea about Xenakis’s sieves, but the article which supposes to be the source is quite a bit difficult to read when you are not familiar with Python and Csound. Also, I tried to read the C++ source code, but still not clear to me. For instance about the parameter alternate, only this line if(unit->alternate_==1) { sign = unit->swap_==1?1.0f:-1.0f; unit->swap_ = 1 - unit->swap_; }, and what about the others value of alternate.
Which is/are the relation between the data values of the buffer, the gap, and alternate for the resynthesis?
Thanks in advance for any clarification.

2

I haven’t read Chris’s article, but I imagine it is more of a reference to Athena CL. I found The Sieves of Iannis Xenakis by Dimitris Exarchos to be an excellent resource for understanding this technique.

Sam

3

Thanks for the reference, but the point is more about this UGen Sieve1. There are as many as you want possibilities about sieves, and I am curious about this one specifically. Unfortunately, my understanding of C++ is limited, so that was the purpose of this topic. It will be nice to have more documentation about the implementation and the parameters or to improve it when there is a lack of it.

4

I did not find this reference.
For those who are interested in sieves, here are some other references to learn more about them:

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5

You could also check out sieves in miSCellaneous_lib. There’s a bunch of classes and analysis tools, but in contrast to Sieve1 it’s language-side. Take the tutorial “Sieves and Psieve patterns” as a starting point.
Currently the audio examples all use sieves as controllers, however, you could also fill buffers with waveforms generated by Sieves / Psieve patterns. Also, arrays filled with sieves could be fed into Duty or other demand rate UGens.

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