fn gamma(x: f64) -> f64Expand description
ROMEO.jl’s γ (src/utility.jl): one wrap only, x ± 2π when x is outside [−π, π].
For the difference of two wrapped phases it is the full wrap; for an unwrapped phase2 (the
previous echo in individual mode) it is not, and ROMEO.jl’s weights are this one’s.