pub fn region_shares(
kernel: &[(f64, f64)],
grid: [usize; 2],
cells: &[Vec<[usize; 2]>],
) -> Vec<Vec<f64>>Expand description
F[r][q], the share of the spread counts arriving evenly over the cells of
region q that the detector records in the cells of region r, for the
regions’ cells cells as [row, column] on a grid of grid rows and
columns. Counts spread to cells in no region, or off the grid, are not
recorded in any region. Each region’s spread image is its cells convolved
with T, by FFT on a grid padded so that no offset wraps.