number-theory functions are available as nt.xxx (e.g. nt.gcd(i,9)==3)
The array variables primes and composites are built in, and list all primes/composites < 1000000.
If the snippet returns true/false, binary filtering is applied i%2==0
If the snippet returns a single float, the result will be used to colour the points, mapping 0.0->1.0 to the plasma colormap i/1000000.0
If the snippet returns an array of 3 floats, the result will be used to colour the points as raw RGB [i/1000000.0, i%2/2.0, i%5/5.0]
Special case If the snippet returns an array of more than 3 floats, these are treated as specific indices to highlight [11,23,55,67,81] or primes