The Sign Node performs the mathematical sign function for each sample in an audio or control signal. That is, each negative sample in the input becomes -1 in the output, and each positive sample 1. The value 0 remains unchanged.
In addition to its obvious use cases for transforming control signals, you can also use the Sign Node to convert most waveforms to a perfect square wave (without band-limiting or anti-aliasing).
Inputs
Control Input
An audio or control signal to transform.
Settings
The Sign Node has no settings.
Outputs
Control Output
An audio or control signal (depending on what you connected to the Audio/Control Input), containing 1, 0, or -1 depending on the input signal.
Technical details
The Sign Node applies the mathematical sign function on a per-sample basis, and makes no effort to band-limit the output. As a result, frequencies above the Nyquist frequency will manifest unless you use a Lowpass Filter Node or similar to add band-limiting.
This is an intentional behavior of this Node.
Similar Nodes
- The Waveshaper Node can also be used to approximate the mathematical sign function, by creating a very sharp transition from -1 to 1 in the middle.
- The Greater Than Zero Node produces identical output for non-negative input signals.