Struct AmrGrid 

pub struct AmrGrid {
    pub root: AmrCell,
    pub domain: Domain,
    pub refinement_threshold: f64,
    pub gradient_threshold: f64,
    pub max_level: usize,
}

Adaptive mesh refinement grid in 6D phase space. The root cell spans the full domain; cells are refined where the distribution function is significant.

Fields

root: AmrCell

Root cell of the tree, spanning the entire 6D domain.

domain: Domain

The simulation domain (spatial/velocity extents, resolutions, BCs).

refinement_threshold: f64

Cells with |f| > refinement_threshold are subdivided.

gradient_threshold: f64

Gradient-based refinement threshold (reserved for future use).

max_level: usize

Maximum refinement level (0 = root only).

Implementations

impl AmrGrid

pub fn new(domain: Domain, refinement_threshold: f64, max_levels: usize) -> Self

Create a new AmrGrid with a single root cell spanning the full 6D domain.

pub fn refine(&mut self)

Refine cells where |f| exceeds the refinement threshold, up to max_level.

pub fn coarsen(&mut self)

Merge children back into parent when their values are nearly uniform (spread < threshold / 10).

pub fn leaf_count(&self) -> usize

Number of leaf cells currently in the tree.

Trait Implementations

impl PhaseSpaceRepr for AmrGrid

fn compute_density(&self) -> DensityField

Compute density rho(x) = integral of f dv^3 by accumulating leaf cell contributions onto the spatial grid.

fn advect_x(&mut self, _displacement: &DisplacementField, dt: f64)

Drift sub-step: shift leaf cell centers in spatial coordinates by v * dt. The velocity coordinates (center[3..6]) of each leaf encode its velocity, so the spatial drift is center[0..3] += center[3..6] * dt.

fn advect_v(&mut self, acceleration: &AccelerationField, dt: f64)

Kick sub-step: shift leaf cell centers in velocity coordinates by a(x) * dt. The acceleration is interpolated from the AccelerationField at the leaf’s spatial position.

fn moment(&self, position: &[f64; 3], order: usize) -> Tensor

Compute velocity moment of order n at the given spatial position. Sums over leaf cells whose spatial center is in the same grid cell.

fn total_mass(&self) -> f64

Total mass M = integral of f dx^3 dv^3 = sum over leaves of f * cell_volume_6D.

fn casimir_c2(&self) -> f64

Casimir invariant C2 = integral of f^2 dx^3 dv^3.

fn entropy(&self) -> f64

Boltzmann entropy S = -integral of f ln(f) dx^3 dv^3.

fn stream_count(&self) -> StreamCountField

Count distinct velocity streams at each spatial position. For each spatial grid cell, count the number of leaf cells that overlap it with significant value (indicating separate velocity-space populations).

fn velocity_distribution(&self, position: &[f64; 3]) -> Vec<f64>

Extract the velocity distribution f(v | x) at a given spatial position. Returns the values of f from all leaf cells whose spatial center maps to the same grid cell as the query position.

fn total_kinetic_energy(&self) -> f64

Total kinetic energy T = (1/2) integral of f * v^2 dx^3 dv^3.

fn to_snapshot(&self, time: f64) -> PhaseSpaceSnapshot

Extract a full 6D snapshot by depositing leaf values onto a uniform grid.

fn as_any(&self) -> &dyn Any

Downcast to concrete type for implementation-specific queries (e.g. HT rank data).

fn load_snapshot(&mut self, snap: PhaseSpaceSnapshot)

Replace the current state with data from a dense 6D snapshot.