Hi all!

I've been working on a patch that (to keep it simple) uses a random number to send out a list of numbers from a selection of 10 lists. The idea is the user can choose to have certain lists not sent through, with the remainder being allowed to go through. I tried to do this by using spigots to 'block' lists if they weren't wanted, however, the random number that selects that list can still go through, meaning if a blocked list is chosen, then nothing is sent.
Does anyone know a good way to work around this, being able to 'remove' a list from being chosen?
(Added screenshot just in case my description made it seem more complicated than it actually was haha)

Any help would be super appreciated!!! ))

@merzben Like this? It rebangs [random] automatically if no output is produced until it gets a hit. Or are we still failing to communicate?
set1.pd

Edit: seems this solution was already suggested and I missed it somehow, oh well, different methods at least. This one also will overflow with nothing selected but both mine and @FFW patch can be fixed by running all of the toggles to a [< 1] and have it's output go to the right inlet of a spigot on the feedback.

N0, [< 1} would not work since turning one off will send 0 to it even if others are on, but you get the ideal, sum them or the like before the [< 1]. Brain has shut down for the day. Good luck.

I'd suggest that an even more elegant solution is to generate the random index such that the undesired values are never produced in the first place.

If you maintain a list of enabled indices, then you could choose randomly from this list, adding and removing available indices based on the toggles.

I'm not at the computer right now, but I could build this in a little while.

It's one of those cases in programming where formulating the problem in one way ("blocking output") biases the mind against other solutions ("constraining the random choices").

hjh

similar to @ddw_music's solution you could also have each list be associated to a number and 2 arrays, one that maps indices to list number and one that maps from list number to index in the 1st array. When a list gets turned off, decrement the range of the rng/highest current index and swap the number with the number of the current highest-index list in the 1st array. Update the index numbers in the 2nd array to reflect that. When a list gets turned back on you do the reverse: swap it with the number lowest currently-off index, increment rng range and update both values in the 2nd array.

Then when you generate a random number you look up which list to route to using the random number as an index into the 1st array. You could use [list prepend] plus [route], or [demultiplex] from zexy.

hopefully that makes some sense.. it's similar to the "urn" algorithm (non-repeating random numbers)
https://stackoverflow.com/questions/196017/unique-non-repeating-random-numbers-in-o1

This is what @ddw_music is getting at. Click a list to add it, click again removes it. Hit the bang on the left and it selects from the lists currently in the [text]. More efficient but can complicate other things, but if it does complicate other things there is a good chance those other things are not being done in the best way and the structure of the patch is worth considering.
set2.pd

Alternate to oid's solution, if you'd rather focus on the random indices and keep a stable collection of lists:

I had considered seb-harmonik's approach to removing the item, but you'd need to iterate to find the index to delete anyway, so I went with a filter operation.

(This, btw, is easier in a text-based programming language where you have proper variables that can be defined once and used in multiple locations, eliminating the need to sync multiple [list] storage locations.)

hjh

@ddw_music you'd use a 2nd array to keep track of the indices

you can use [array random]

withArrayRandom.pd

@seb-harmonik.ar said:

@ddw_music you'd use a 2nd array to keep track of the indices

Ah ok, overlooked that. "Exercise for the reader"...

hjh

@oid thanks so much for this!!! perfectly simple solution, did exactly what I needed. I combined this with the non-repeating random numbers above.