Rationals and Modulo

[daniel-frisch-kit]

Differentiation with modulo function yields a Float, even for Rational input.

What doesn't work:

ForwardDiff.derivative(x->mod(x^2,1), 1//3)
0.6666666666666666

What works:

ForwardDiff.derivative(x->x^2, 1//3)
2//3

mod(1//2,1)
1//2