If I don't want to incur a dependency on cyclone, how would I do the equivalent of [gate]?

I find that I need this very often, but I don't see it in the core objects. (Or, if I need it fairly often and Pd doesn't need to provide it, then maybe I'm thinking about the signal flow in the wrong way, and there might be another way to structure things.)

For example, if I have some control data and I want to switch between three different calculation paths, my instinct is control data --> [gate] --> 3 outputs. But maybe there's another way?

hjh

@ddw_music I've made a vanilla [gate] but you also need [initbang] (another dependency) to make anything with a dynamic number of outlets at creation time

@seb-harmonik.ar In Pd 0.49.1, an equivalent to [initbang] can be made with [savestate] as shown here by @solipp:
https://forum.pdpatchrepo.info/topic/12066/store-state-patch-less-state-saving-method-for-abstractions/9

I've made a vanilla [gate] but you also need [initbang] (another dependency) to make anything with a dynamic number of outlets at creation time.

Cool, interesting. I went to your github link and found there is a signal [gate~] but I don't see the one for [gate].

My main reason for asking is about the methodology. I'm a long-time SuperCollider user, now considering PD for an interactive multimedia course that will begin next spring, for a couple of reasons -- a/ while I think SC is better able to handle complex requirements, the code frightens students who don't want to think of themselves as programmers (even though data flow programming is programming, with the boxes and wires, I can lie to them and they'll believe it), and b/ SC doesn't have built-in video capability (and I really hesitate to make the class SC + Processing, one programming language is already too much).

I use SC because I "get" code in a way that I don't naturally "get" data flows. So I'm asking how I should think about this programming task -- one data source, fed out to one of several paths that can be dynamically selected. In SC, if it's "language-side" processing (analogous to pd simple messages), I would use a switch statement or a collection of functions; if it's signal processing, I would use PanAz (multichannel panner).

I could imagine [prepend]-ing an index number onto the value to pass through, and then using [route]. But I'm not fluent enough in data flows to know if this would be considered "elegant" or "kludgey."

hjh

@ddw_music Pd is all about messages...... and so it is all about lists..... strings of data "grouped" together as a "thing".
A string...... but not... because the atoms are all separate and can be of different types.... symbols, floats, etc.
So then it becomes about manipulating those lists.
Sub-routines can be called..... and we call them abstractions..... and they can be given arguments at creation or passed arguments whilst running.
Abstractions can also be created or even built dynamically by sending messages to a patch or sub-patch.
Externals...... abstractions that run code..... have been made by some clever people.

Tagging the data as you suggest is one way of sorting.
You can also sort by position in a list...... by undeclared index.
The list-abs library of abstractions contains much of what you will need, although there are newer externals in recent Pd Vanilla that can achieve the same.
I uploaded it recently here if you need it....... https://forum.pdpatchrepo.info/topic/12125/how-should-i-use-list-drip-to-compare-another-list-drip-s-items/12

The real difference of data flow programming is that it is always "running".
So mistakes are seen straight away which is a huge advantage for us noobs.
David.

What are the conditions?

• "I want to trigger on of several paths based on a single float or symbol value" = [select]
• "I want a single float message to make a path through the diagram based on its value" = [moses]
• "I want a multi-atom message to make a path through the diagram based on the value of either the message selector or the leading float element" = [route] (note: leading float will get sliced off)
• "I want a message to make a path through the diagram based on a calculation other than equality check" = reduce a calculation to 0/1 for [spigot] or reduce a calculation to an index and prepend it for [route]

@ddw_music I would consider the solution with [route] as elegant and the way to go

I've managed to do a vanilla version using [savestate]. However, because [savestate] only responds after being saved, whenever you change the arguments (or recreate it) the connections will disappear because the first time it is created [loadbang] has to be used (because there's nothing saved for the object the first time)
pdgate.zip

@ingox "I would consider the solution with [route] as elegant and the way to go"

Thank you! So I'm not missing anything obvious

@jancsika Good summary, thanks.

@whale-av "Pd is all about messages...... and so it is all about lists"

Right, I understand arrays. (In SC, array elements are just references to objects rather than a fixed data types, so, like pd lists, each element can be a different type -- ['selector', 4.0] is valid as both an SC array and a pd list.) I haven't spent enough time with pd's list manipulation objects, but I will have to, soon.

list-abs is a good tip, thanks. Seems to have a lot of equivalents of SC's array operations ([list-add] = array1 + array2, [list-drip] --> Pseq(array, 1).asStream).

You can also sort by position in a list...... by undeclared index.

That one is beyond me at this point.

The real difference of data flow programming is that it is always 'running'. So mistakes are seen straight away which is a huge advantage for us noobs.

Hm, signal processing is always running, and GEM is always running, but messages are running only when something is triggering them, right? If I "play" a Routine in SC, then that is always running (until stopped), not really any different from a pd object graph triggered periodically by [metro].

I think what's more approachable about data flows is that a patch cord on screen is "concrete" in a way that function arguments in code are not. (But I'll still use SC for my own work because I find it easier to scale up to high complexity.)

hjh

@ddw_music "You can also sort by position in a list...... by undeclared index."
I should have mentioned ...... [unpack]
Unfortunately it expects floats or symbols in a specific position.
I.E [3.5 4 woof(
into [unpack f f s]
You can join data into lists with [pack]
You can also re-order the list passing it through a message ...... [$3 $1 $2(
https://forum.pdpatchrepo.info/topic/9774/pure-data-noob/4

"Hm, signal processing is always running, and GEM is always running, but messages are running only when something is triggering them, right?"
True, but if data is flowing and you make/ break a connection you see the result immediately.

In Pd Extended there was an edit tool.... "Magic Glass" that would show data and audio travelling through cords. Now, unfortunately, your only friends are [print] and [print~]
David.