rusty-tree 0.0.1

Octree data structures in Rust.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112

//! Data structures and functions for regular octrees.
//! 
//! This module implements a regular Octree data structure.
//! A regular tree subdivides uniformly on all levels. To avoid
//! dealing with many empty boxes only the non-empty leaf boxes
//! are actually being stored.

use super::{Statistics, Octree, OctreeType};
use ndarray::{ArrayView2, Axis};
use rusty_kernel_tools::RealType;
use std::time::Instant;


/// Create a regular Octree.
///
/// Returns a `RegularOctree` struct describing a regular octree.
///
/// # Arguments
/// * `particles` - A (3, N) array of particles of type f32 or f64.
/// * `max_level` - The maximum level of the tree.
pub fn regular_octree<T: RealType>(
    particles: ArrayView2<T>,
    max_level: usize,
) -> Octree<'_, T> {
    use crate::helpers::compute_bounds;

    const TOL: f64 = 1E-5;

    let bounds = compute_bounds(particles);
    let diameter = [
        (bounds[0][1] - bounds[0][0]).to_f64().unwrap() * (1.0 + TOL),
        (bounds[1][1] - bounds[1][0]).to_f64().unwrap() * (1.0 + TOL),
        (bounds[2][1] - bounds[2][0]).to_f64().unwrap() * (1.0 + TOL),
    ];

    let origin = [
        bounds[0][0].to_f64().unwrap(),
        bounds[1][0].to_f64().unwrap(),
        bounds[2][0].to_f64().unwrap(),
    ];

    regular_octree_with_bounding_box(particles, max_level, origin, diameter)
}

/// Create a regular Octree with given bounding box.
///
/// Returns a `RegularOctree` struct describing a regular octree.
///
/// # Arguments
/// * `particles` - A (3, N) array of particles of type f32 or f64.
/// * `max_level` - The maximum level of the tree.
/// `origin` - The origin of the bounding box.
/// `diameter` - The diameter of the bounding box in each dimension.
pub fn regular_octree_with_bounding_box<T: RealType>(
    particles: ArrayView2<T>,
    max_level: usize,
    origin: [f64; 3],
    diameter: [f64; 3],
) -> Octree<'_, T> {
    use crate::morton::encode_points;
    use super::{compute_near_field_map, compute_interaction_list_map, compute_leaf_map, compute_level_information};

    let now = Instant::now();


    let leaf_keys = encode_points(particles, max_level, &origin, &diameter);
    let (max_level, all_keys, level_keys) = compute_level_information(leaf_keys.view());
    let leaf_key_to_particles = compute_leaf_map(leaf_keys.view());

    let near_field = compute_near_field_map(&all_keys);
    let interaction_list = compute_interaction_list_map(&all_keys);

    let duration = now.elapsed();

    let statistics = Statistics {
        number_of_particles: particles.len_of(Axis(1)),
        max_level,
        number_of_leafs: leaf_key_to_particles.keys().len(),
        number_of_keys: all_keys.len(),
        creation_time: duration,
        minimum_number_of_particles_in_leaf: leaf_key_to_particles
            .values()
            .map(|item| item.len())
            .reduce(std::cmp::min)
            .unwrap(),
        maximum_number_of_particles_in_leaf: leaf_key_to_particles
            .values()
            .map(|item| item.len())
            .reduce(std::cmp::max)
            .unwrap(),
        average_number_of_particles_in_leaf: (leaf_key_to_particles
            .values()
            .map(|item| item.len())
            .sum::<usize>() as f64)
            / (leaf_key_to_particles.keys().len() as f64),
    };

    Octree {
        particles,
        max_level,
        origin,
        diameter,
        level_keys,
        particle_keys: leaf_keys,
        near_field,
        interaction_list,
        leaf_key_to_particles,
        all_keys,
        octree_type: OctreeType::Regular,
        statistics,
    }
}