use std::error::Error;
use crate::{matrix::*, number::Number};
#[derive(Clone, Debug, Default, Hash)]
pub struct BidiagonalMatrix<T = f64>
where
T: Number,
{
d: Vec<T>,
e: Vec<T>,
}
impl<T> BidiagonalMatrix<T>
where
T: Number,
{
pub fn new(d: Vec<T>, e: Vec<T>) -> Result<Self, Box<dyn Error>> {
if d.len().max(1) - 1 != e.len() {
return Err(MatrixError::DimensionMismatch.into());
}
Ok(Self { d, e })
}
pub fn d(&self) -> &[T] {
&self.d
}
pub fn e(&self) -> &[T] {
&self.e
}
pub fn eject(self) -> (Vec<T>, Vec<T>) {
(self.d, self.e)
}
pub fn mat(&self, upper: bool) -> Matrix<T> {
let n = self.d.len();
let mut mat = Matrix::diag(&self.d);
if upper {
for i in 0..n - 1 {
mat[i + 1][i] = self.e[i];
}
} else {
for i in 0..n - 1 {
mat[i][i + 1] = self.e[i];
}
}
mat
}
}