fn c2f_put<T: Real>(
out: &mut [T],
t: usize,
sum: T,
w: f64,
cor: bool,
prefac: f64,
)Expand description
One value MG::C2F writes at fine index t: the mean sum · w of the coarse values around
it (w = 1/2, 1/4, 1/8), formed in double as the C++ does (/2.0 is a double literal). As a
correction it is scaled by prefac and added to the fine value in double, then rounded.