Pure Data help. How to use conditional logic in Pd

Question

I've confused my myself a lot and need your help. I'm trying to make a little function in Pure Data which says when the toggle is on it sends a 1 but when it isn't on it allows the computed value through.

So the program works a value 1 or 2 and when the toggle isn't on the computed value goes through, but when the togggle is on it sends 1 through.

I would show my code but its Pd so I can't copy and paste it. My attempt so far is making use of spigots but that isn't working its still sending 1 through no matter what the toggle is doing, and I know for a fact the computed value changes.

In normal code I would do something like:

value = computedVal

if (toggle == 1) then return 1;

else return value;

Answer 1

Much simpler solution, and you can set the toggle value to any number, 0 is off, any number larger than 0 is on.

Answer 2

There is more than one way to solve this. Assuming that you want a 1 to be sent out each time the computedVal changes while toggle is 1, it could look like this:

Answer 3

Here's a solution using a demultiplexer idiom:

It basically prefixes the incoming message with a label (0 or 1), and then routes the data accordingly.

In general, you should learn to think in data flow, rather than control flow: how do you get the data to that part of the patch where it is needed. Trying to mimick control flow (if ... then ..., or worse while ... do ...) will only melt your brains.

Answer 4

It's best to keep the flow in the same type from start to finish (in this case a float). You can make a solution using only [f ], [pack], [t b], [t b f], and [route] objects. Maybe a [swap] if you're feeling fancy. The [spigot] object is more useful for not sending messages.

Also, if I understand correctly, you might be having trouble with [toggle] itself. The [toggle] object will be on given any non-zero value and off with a zero value. If you are giving [toggle] a one(1) or a two(2) it will act as if it's on in both cases. You could use [==] to fix this which will output a true(1) or a false(0) but only if you supply an argument like [== 1]. This way two(2) will register as a zero(0), turn [toggle] off, and return your value.

Two examples of alternative solutions:

Honestly though, for less headaches and reusability and simplicity, you should consider picking a pattern in your workflow similar to Pure Data 's inherent true(1) and false(0) paradigm. It will make logic a lot simpler in your future endeavors and is much more similar to the c-logic in which Pure Data is coded and emulates.

This way, if your logic statement accepts or returns a zero(0) as false and a non-zero as true, it will work more 'logically' with other pre-built Pure Data objects. Then your logic might look like the screen below.

More cohesive conditional logic:

I hope it helps!