use super::SparseMatrix;
use crate::{matrix::Matrix, number::Number};
use std::ops::Mul;
fn mul<T>(slf: &SparseMatrix<T>, rhs: &Matrix<T>) -> Matrix<T>
where
T: Number,
{
if slf.cols != rhs.rows {
panic!("Dimension mismatch.");
}
let mut new_matrix = Matrix::new(slf.rows, rhs.cols);
for (&(i, j), &s) in slf.elems.iter() {
for k in 0..rhs.cols {
new_matrix[i][k] += s * rhs[j][k];
}
}
new_matrix
}
impl<T> Mul<Matrix<T>> for SparseMatrix<T>
where
T: Number,
{
type Output = Matrix<T>;
fn mul(self, rhs: Matrix<T>) -> Self::Output {
mul(&self, &rhs)
}
}
impl<T> Mul<&Matrix<T>> for SparseMatrix<T>
where
T: Number,
{
type Output = Matrix<T>;
fn mul(self, rhs: &Matrix<T>) -> Self::Output {
mul(&self, rhs)
}
}
impl<T> Mul<Matrix<T>> for &SparseMatrix<T>
where
T: Number,
{
type Output = Matrix<T>;
fn mul(self, rhs: Matrix<T>) -> Self::Output {
mul(self, &rhs)
}
}
impl<T> Mul<&Matrix<T>> for &SparseMatrix<T>
where
T: Number,
{
type Output = Matrix<T>;
fn mul(self, rhs: &Matrix<T>) -> Self::Output {
mul(self, rhs)
}
}
#[cfg(test)]
mod tests {
use crate::*;
#[test]
fn it_works() {
let mut a = SparseMatrix::new(2, 3);
a[(0, 0)] = 1.0;
a[(0, 1)] = 2.0;
a[(1, 2)] = 3.0;
let b = mat![
1.0, 3.0;
2.0, 4.0;
3.0, 6.0
];
let c = a * b;
assert_eq!(c[0][0], 5.0);
assert_eq!(c[1][1], 18.0);
}
}