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
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131

use crate::algebra::linear::{Matrix};
use crate::algebra::abstr::{Scalar, Field};
use std::ops::{Sub};

impl <T> Sub for Matrix<T>
    where T: Field + Scalar
{
    type Output = Matrix<T>;

    /// Subtracts two matrices
    ///
    /// A = (a_{ij}) \in T^{m \times n}
    /// B = (b_{ij}) \in T^{m \times n}
    /// A - B = ( a_{ij} - b_{ij} )
    ///
    /// # Arguments
    ///
    /// rhs:
    ///
    /// # Example
    ///
    /// ```
    /// use mathru::algebra::linear::{Matrix};
    ///
    /// let a: Matrix<f64> = Matrix::new(2, 2, vec![1.0, 0.0, 3.0, -7.0]);
    /// let b: Matrix<f64> = Matrix::new(2, 2, vec![1.0, 0.0, 3.0, -7.0]);
    ///
    /// assert_eq!(Matrix::zero(2, 2), a - b);
    /// ```
    fn sub(self: Self, rhs: Self) -> Self::Output
    {
        (&self).sub(&rhs)
    }
}


impl<'a, 'b, T> Sub<&'b Matrix<T>> for &'a Matrix<T>
    where T: Field + Scalar
{
    type Output = Matrix<T>;

    fn sub(self: Self, rhs: &'b Matrix<T>) -> Self::Output
    {
        assert_eq!(self.dim(), rhs.dim());
        return self.sub_r(rhs);
    }
}

impl<'a, 'b, T> Matrix<T>
    where T: Field + Scalar
{
    #[cfg(feature = "native")]
    fn sub_r(self: &Self, rhs: &'b Matrix<T>) -> Matrix<T>
    {
        let (m, n) = rhs.dim();
        Matrix
        {
            m: m,
            n: n,
            data: self.data.iter().zip(rhs.data.iter()).map(|(x, y)| *x - *y).collect::<Vec<T>>()
        }
    }

    #[cfg(feature = "blaslapack")]
    fn sub_r(self: &Self, rhs: &'b Matrix<T>) -> Matrix<T>
    {
        let mut c: Matrix<T> = rhs.clone();
        let (b_m, b_n): (usize, usize) = rhs.dim();

        let a: Matrix<T> = Matrix::one(b_m);
        let m: i32 = b_m as i32;
        let n: i32 = b_n as i32;
        let k: i32 = b_m as i32;


        T::xgemm('N' as u8, 'N' as u8, m, n, k, T::one(), &a.data[..], m, &self.data[..], k, -T::one(), &mut c.data[..],
         m);

        return c;
    }
}


///
/// Subtracts scalar from all matrix elements
///
impl<'a, 'b, T> Sub<&'b T> for &'a Matrix<T>
    where T: Field + Scalar
{
    type Output = Matrix<T>;

    /// Subtracts a scalar value from all matrix elements
    ///
    /// # Example
    ///
    /// ```
    /// use mathru::algebra::linear::{Matrix};
    ///
    /// let a: Matrix<f64> = Matrix::new(2, 2, vec![1.0, 0.0, 3.0, -7.0]);
    /// let b: Matrix<f64> = Matrix::new(2, 2, vec![5.0, 4.0, 7.0, -3.0]);
    ///
    /// assert_eq!(b, &a - &-4.0);
    /// ```
    fn sub(self: Self, rhs: &T) -> Self::Output
    {
        return self.apply(&|x: &T| -> T {x.clone() - rhs.clone()});
    }
}

impl<T> Sub<T> for Matrix<T>
    where T: Field + Scalar
{
    type Output = Matrix<T>;

    /// Subtracts a scalar from all matrix elements
    ///
    /// # Example
    ///
    /// ```
    /// use mathru::algebra::linear::{Matrix};
    ///
    /// let a: Matrix<f64> = Matrix::new(2, 2, vec![1.0, 0.0, 3.0, -7.0]);
    /// let b: Matrix<f64> = Matrix::new(2, 2, vec![5.0, 4.0, 7.0, -3.0]);
    ///
    /// assert_eq!(b, a - -4.0);
    /// ```
    fn sub(self: Self, rhs: T) -> Self::Output
    {
        return (&self).sub(&rhs);
    }
}