matrix 0.22.0

The package provides a matrix laboratory.
Documentation
use format::{Compressed, Conventional, Diagonal};
use operation::{Multiply, MultiplyInto, MultiplySelf, Transpose};
use {Element, Number};

impl<T> Multiply<Diagonal<T>, Compressed<T>> for Compressed<T>
where
    T: Element + Number,
{
    #[inline]
    fn multiply(&self, right: &Diagonal<T>) -> Self {
        let mut result = self.clone();
        result.multiply_self(right);
        result
    }
}

impl<'l, T> MultiplyInto<[T], [T]> for Compressed<T>
where
    T: Element + Number,
{
    #[inline]
    fn multiply_into(&self, right: &[T], result: &mut [T]) {
        let (m, p) = (self.rows, self.columns);
        let n = right.len() / p;
        multiply_matrix_left(self, right, result, m, p, n)
    }
}

impl<'l, T> MultiplyInto<Compressed<T>, [T]> for Conventional<T>
where
    T: Element + Number,
{
    #[inline]
    fn multiply_into(&self, right: &Compressed<T>, result: &mut [T]) {
        let (m, p, n) = (self.rows, self.columns, right.columns);
        multiply_matrix_right(&self.values, right, result, m, p, n)
    }
}

impl<T> MultiplySelf<Diagonal<T>> for Compressed<T>
where
    T: Element + Number,
{
    fn multiply_self(&mut self, right: &Diagonal<T>) {
        let (m, n) = (self.rows, right.columns);
        debug_assert_eq!(self.columns, right.rows);
        self.resize((m, n));
        for (_, j, value) in self.iter_mut() {
            *value = *value * right[j];
        }
    }
}

impl<T: Element> Transpose for Compressed<T> {
    fn transpose(&self) -> Self {
        let &Compressed {
            rows,
            columns,
            nonzeros,
            variant,
            ..
        } = self;
        let mut matrix = Compressed::with_capacity((columns, rows), variant, nonzeros);
        for (i, j, &value) in self.iter() {
            matrix.set((j, i), value);
        }
        matrix
    }
}

fn multiply_matrix_left<T>(a: &Compressed<T>, b: &[T], c: &mut [T], m: usize, p: usize, n: usize)
where
    T: Element + Number,
{
    debug_assert_eq!(a.rows * a.columns, m * p);
    debug_assert_eq!(b.len(), p * n);
    debug_assert_eq!(c.len(), m * n);
    let &Compressed {
        ref values,
        ref indices,
        ref offsets,
        ..
    } = a;
    for j in 0..n {
        let bo = j * p;
        let co = j * m;
        for l in 0..p {
            let bi = bo + l;
            for k in offsets[l]..offsets[l + 1] {
                let i = co + indices[k];
                c[i] = c[i] + values[k] * b[bi];
            }
        }
    }
}

fn multiply_matrix_right<T>(a: &[T], b: &Compressed<T>, c: &mut [T], m: usize, p: usize, n: usize)
where
    T: Element + Number,
{
    debug_assert_eq!(a.len(), m * p);
    debug_assert_eq!(b.rows * b.columns, p * n);
    debug_assert_eq!(c.len(), m * n);
    let &Compressed {
        ref values,
        ref indices,
        ref offsets,
        ..
    } = b;
    for j in 0..n {
        let co = j * m;
        for k in offsets[j]..offsets[j + 1] {
            let ao = indices[k] * m;
            for i in 0..m {
                c[co + i] = c[co + i] + values[k] * a[ao + i];
            }
        }
    }
}

#[cfg(test)]
mod tests {
    use format::compressed::Variant;
    use prelude::*;

    #[test]
    fn multiply_self() {
        let mut matrix = new!(
            3,
            2,
            3,
            Variant::Column,
            vec![1.0, 2.0, 3.0],
            vec![1, 0, 2],
            vec![0, 1, 3]
        );
        let right = Diagonal::from_vec((2, 4), vec![4.0, 5.0]);
        matrix.multiply_self(&right);
        assert_eq!(
            matrix,
            new!(
                3,
                4,
                3,
                Variant::Column,
                vec![4.0, 10.0, 15.0],
                vec![1, 0, 2],
                vec![0, 1, 3, 3, 3]
            )
        );
    }

    #[test]
    fn multiply_into_left() {
        let matrix = Compressed::from(Conventional::from_vec(
            (4, 3),
            matrix![
                1.0, 5.0, 4.0;
                2.0, 6.0, 3.0;
                3.0, 6.0, 2.0;
                4.0, 5.0, 1.0;
            ],
        ));
        let right = Conventional::from_vec(
            (3, 2),
            matrix![
                1.0, 4.0;
                2.0, 5.0;
                3.0, 6.0;
            ],
        );
        let mut result = Conventional::from_vec(
            (4, 2),
            matrix![
                1.0, 1.0;
                1.0, 1.0;
                1.0, 1.0;
                1.0, 1.0;
            ],
        );
        matrix.multiply_into(&right, &mut result);
        assert_eq!(
            &result.values,
            &matrix![
                24.0, 54.0;
                24.0, 57.0;
                22.0, 55.0;
                18.0, 48.0;
            ]
        );
    }

    #[test]
    fn multiply_into_right() {
        let matrix = Conventional::from_vec(
            (4, 3),
            matrix![
                1.0, 5.0, 4.0;
                2.0, 6.0, 3.0;
                3.0, 6.0, 2.0;
                4.0, 5.0, 1.0;
            ],
        );
        let right = Compressed::from(Conventional::from_vec(
            (3, 2),
            matrix![
                1.0, 4.0;
                2.0, 5.0;
                3.0, 6.0;
            ],
        ));
        let mut result = Conventional::from_vec(
            (4, 2),
            matrix![
                1.0, 1.0;
                1.0, 1.0;
                1.0, 1.0;
                1.0, 1.0;
            ],
        );
        matrix.multiply_into(&right, &mut result);
        assert_eq!(
            &result.values,
            &matrix![
                24.0, 54.0;
                24.0, 57.0;
                22.0, 55.0;
                18.0, 48.0;
            ]
        );
    }

    #[test]
    fn transpose() {
        let matrix = new!(
            5,
            7,
            5,
            Variant::Column,
            vec![1.0, 2.0, 3.0, 4.0, 5.0],
            vec![1, 0, 3, 1, 4],
            vec![0, 0, 0, 1, 2, 2, 3, 5]
        );
        let matrix = matrix.transpose();
        assert_eq!(
            matrix,
            new!(
                7,
                5,
                5,
                Variant::Column,
                vec![2.0, 1.0, 4.0, 3.0, 5.0],
                vec![3, 2, 6, 5, 6],
                vec![0, 1, 3, 3, 4, 5]
            )
        );
    }
}