Struct FftIsolated 

pub struct FftIsolated {
    pub shape: [usize; 3],
    pub dx: [f64; 3],
    /* private fields */
}

👎Deprecated since 0.0.11:

use VgfPoisson for isolated BC; FftIsolated will be removed in a future release

Isolated-boundary-condition Poisson solver using the Hockney-Eastwood zero-padding method.

Embeds the N^3 density field into a (2N)^3 periodic box, convolves with the precomputed Fourier-space free-space Green’s function G(r) = -1/(4pir), and extracts the N^3 interior to obtain the potential with correct vacuum boundary conditions. O(N^3 log N).

FFT plans and the Green’s function FFT are precomputed at construction time for the (2N)^3 grid. Acceleration is computed via second-order finite differences (not spectral).

Deprecated: Prefer VgfPoisson which provides spectral-accuracy isolated boundary conditions with lower memory overhead.

Fields

shape: [usize; 3]

👎Deprecated since 0.0.11:

use VgfPoisson for isolated BC; FftIsolated will be removed in a future release

Number of grid cells along each spatial axis [nx, ny, nz] (physical grid, not padded).

dx: [f64; 3]

👎Deprecated since 0.0.11:

use VgfPoisson for isolated BC; FftIsolated will be removed in a future release

Grid spacing along each spatial axis [dx, dy, dz].

Implementations

impl FftIsolated

pub fn new(domain: &Domain) -> Self

Create a new isolated-BC Poisson solver, precomputing FFT plans and the Green’s function.

Builds the free-space Green’s function G(r) = -1/(4pir) on the (2N)^3 padded grid with minimum-image wrapping, then forward-transforms it for reuse in every solve() call.

Trait Implementations

impl PoissonSolver for FftIsolated

fn solve(&self, density: &DensityField, g: f64) -> PotentialField

Solve nabla^2 Phi = 4piG*rho with isolated BC via Hockney-Eastwood convolution.

Zero-pads rho into (2N)^3, forward-FFTs, multiplies pointwise with the cached Green’s function, inverse-FFTs, and extracts the N^3 physical sub-grid.

fn compute_acceleration(&self, potential: &PotentialField) -> AccelerationField

Compute gravitational acceleration via second-order centered finite differences.

fn set_progress(&mut self, p: Arc<StepProgress>)

Attach shared progress state for intra-phase cell-level reporting.