Asymmetric soft clipper with level parameter

softclip2.gp

# CC0-1.0 or MIT

# asymmetric soft clipping waveshaper
# k: the curve control parameter (0 excl. to 1)

cubic(x)=(x*x*x/3)
lm(k)=-sqrt(k*k*k)/(k*k*k) # the local minimum

kubic(k,x)=x-cubic(k*x)
max(a,b)=(a>b)?a:b
nl(k,x)=(x>0)?x:kubic(k,max(x,lm(k)))

z=2./3.;
nl2(k,x)=nl(k,x-z)+z

set xrange [-1:+1]
plot nl2(0.2,x) t "2", nl2(0.3,x) t "3", nl2(0.4,x) t "4", nl2(0.5,x) t "5", nl2(0.6,x) t "6", nl2(0.7,x) t "7", nl2(0.8,x) t "8", nl2(0.9,x) t "9", nl2(1.0,x) t "10"