Having issues understanding index calculation

[nambastha]

Hi David

I'm trying to understand how the index is getting calculated in your code.

SmallHilbertCurve c = 
    HilbertCurve.small().bits(1).dimensions(2);
//returns long rather than BigInteger
long index = c.index(0,2);

It returns 0. Can you help me in understanding how it's 0 as distance between point 0 to 2 should come as 2.

Thanks in advance.

[davidmoten]

You are trying an extreme case. By setting bits=1 then each of the axes varies from 0 to 1 only. Thus in fact (0,2) is outside the domain and probably wraps around to (0,0).