Function fdsolve

pub fn fdsolve<T>(
    a: &ArrayView2<'_, f64>,
    b: &ArrayView1<'_, T>,
    allow_lsq: bool,
) -> Array1<T>
where
    T: PartialOrd + Signed + Clone + Zero + Sum,
    for<'a> &'a f64: Mul<&'a T, Output = T>,
    for<'a> &'a T: Sub<&'a T, Output = T>,

Solve a linear system, ax = b, using Gaussian elimination and partial pivoting.

The LHS contains f64s and the RHS is generic. allow_lsq can be true is the number of rows in a is greater than the number of columns.