use_eigen/
eigensystem.rs

1use crate::{EigenError, Eigenpair};
2
3/// A non-empty collection of eigenpairs.
4#[derive(Debug, Clone, PartialEq, Eq)]
5pub struct Eigensystem<T> {
6    pairs: Vec<Eigenpair<T>>,
7}
8
9impl<T> Eigensystem<T> {
10    /// Creates a new eigensystem.
11    ///
12    /// # Errors
13    ///
14    /// Returns [`EigenError::EmptyEigensystem`] when `pairs` is empty.
15    pub fn new(pairs: Vec<Eigenpair<T>>) -> Result<Self, EigenError> {
16        Self::try_new(pairs)
17    }
18
19    /// Creates a new eigensystem.
20    ///
21    /// # Errors
22    ///
23    /// Returns [`EigenError::EmptyEigensystem`] when `pairs` is empty.
24    pub fn try_new(pairs: Vec<Eigenpair<T>>) -> Result<Self, EigenError> {
25        if pairs.is_empty() {
26            Err(EigenError::EmptyEigensystem)
27        } else {
28            Ok(Self { pairs })
29        }
30    }
31
32    /// Creates a new eigensystem from eigenpairs.
33    ///
34    /// # Errors
35    ///
36    /// Returns [`EigenError::EmptyEigensystem`] when `pairs` is empty.
37    pub fn from_pairs(pairs: Vec<Eigenpair<T>>) -> Result<Self, EigenError> {
38        Self::try_new(pairs)
39    }
40
41    /// Returns the stored eigenpairs.
42    #[must_use]
43    pub fn pairs(&self) -> &[Eigenpair<T>] {
44        &self.pairs
45    }
46
47    /// Returns the stored eigenpairs.
48    #[must_use]
49    pub fn into_inner(self) -> Vec<Eigenpair<T>> {
50        self.pairs
51    }
52
53    /// Returns the number of stored eigenpairs.
54    #[must_use]
55    pub const fn len(&self) -> usize {
56        self.pairs.len()
57    }
58
59    /// Returns whether the eigensystem is empty.
60    #[must_use]
61    pub const fn is_empty(&self) -> bool {
62        self.pairs.is_empty()
63    }
64}
65
66impl<T> AsRef<[Eigenpair<T>]> for Eigensystem<T> {
67    fn as_ref(&self) -> &[Eigenpair<T>] {
68        self.pairs()
69    }
70}
71
72#[cfg(test)]
73mod tests {
74    use super::Eigensystem;
75    use crate::{EigenError, Eigenpair, Eigenvalue, Eigenvector};
76
77    #[test]
78    fn stores_multiple_eigenpairs() {
79        let pairs = vec![
80            Eigenpair::new(
81                Eigenvalue::new(2_i32),
82                Eigenvector::new(vec![1_i32, 0]).expect("valid eigenvector"),
83            ),
84            Eigenpair::new(
85                Eigenvalue::new(5_i32),
86                Eigenvector::new(vec![0_i32, 1]).expect("valid eigenvector"),
87            ),
88        ];
89
90        let system = Eigensystem::new(pairs).expect("valid eigensystem");
91
92        assert_eq!(system.len(), 2);
93        assert_eq!(*system.pairs()[0].value().as_ref(), 2);
94        assert_eq!(system.pairs()[1].vector().coordinates(), &[0, 1]);
95    }
96
97    #[test]
98    fn rejects_an_empty_eigensystem() {
99        assert_eq!(
100            Eigensystem::<i32>::new(vec![]),
101            Err(EigenError::EmptyEigensystem)
102        );
103    }
104}
use_eigen/eigensystem.rs

use_eigen/
eigensystem.rs
