fn channel_matrix<I: Iterator<Item = [Complex; 2]>>(
multipoles: usize,
planes: usize,
entries: impl Fn(usize, usize) -> Result<I> + Sync,
) -> Result<DMatrix<Complex>>Expand description
Assemble incident/radiated pairs, constructing each channel once per side. Each worker owns complete plane-mode columns without buffering intermediate values.