sukker 1.0.1

Matrices in rust
Documentation 
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//! Internal helper methods for determinant calculation
#![warn(missing_docs)]
use crate::Matrix;

/// Calculates a 2x2 determinant
///
/// # Examples
pub fn determinant_2x2(matrix: &Matrix) -> f32 {
    let a = matrix.data[0];
    let b = matrix.data[1];
    let c = matrix.data[2];
    let d = matrix.data[3];

    a * d - b * c
}

/// Calculates a 3x3 determinant
pub fn determinant_3x3(matrix: &Matrix) -> f32 {
    let a = matrix.data[0];
    let b = matrix.data[1];
    let c = matrix.data[2];
    let d = matrix.data[3];
    let e = matrix.data[4];
    let f = matrix.data[5];
    let g = matrix.data[6];
    let h = matrix.data[7];
    let i = matrix.data[8];

    a * (e * i - f * h) - b * (d * i - f * g) + c * (d * h - e * g)
}

/// Gets the next inner layer of a determinant calculation
pub fn get_minor(matrix: &Matrix, size: usize, col: usize) -> Vec<f32> {
    (1..size)
        .flat_map(|i| (0..size).map(move |j| (i, j)))
        .filter_map(|(i, j)| {
            if j != col {
                Some(matrix.data[i * size + j])
            } else {
                None
            }
        })
        .collect()
}