#lang scribble/manual @(require (for-label racket)) @title{(sign a)} Sign function. -1 when a < 0, +1 when a > 0, 0 when a is 0 @racketblock[ (let* ((a (line ar -1 1 1 remove-synth)) (b (sign a)) (f (mul-add (mce2 a b) 600 900))) (audition (out 0 (mul (sin-osc ar f 0) 0.1)))) ]