int seed = set(ch("seed"));
float strength = ch("strength");

// trying out smoothing between two random values
float smoothedRand = smooth(random(seed + @pointnum),random(seed + @pointnum+1), 0.5);

// moving random from 0 to 1 to -0.5 to 0.5
float equalized = 0.5 -smoothedRand;

// y pos displaced based to rand * strength param
float randomDisplace =  smoothedRand * strength;
@P.y += randomDisplace;

// using the same rand value to scale the particles
@pscale = fit(smoothedRand, 0, 1, 0, 3);