Parametric Curves org.inkscape.effect.param_curves 0.0 1.0 true -1.0 1.0 -1.0 1.0 30 false When set, Isotropic scaling uses smallest of width/xrange or height/yrange Select a rectangle before calling the extension, it will determine X and Y scales. First derivatives are always determined numerically. Standard Python math functions are available: ceil(x); fabs(x); floor(x); fmod(x,y); frexp(x); ldexp(x,i); modf(x); exp(x); log(x [, base]); log10(x); pow(x,y); sqrt(x); acos(x); asin(x); atan(x); atan2(y,x); hypot(x,y); cos(x); sin(x); tan(x); degrees(x); radians(x); cosh(x); sinh(x); tanh(x). The constants pi and e are also available. cos(3*t) sin(5*t) true false rect