Adds OLS and naive linear algebra routine

src/linalg/mod.rs

@@ -0,0 +1,31 @@
+use std::ops::Range;
+
+pub mod naive;
+
+pub trait Matrix: Into<Vec<f64>>{ 
+
+    fn get(&self, row: usize, col: usize) -> f64; 
+
+    fn qr_solve_mut(&mut self, b: Self) -> Self;
+
+    fn zeros(nrows: usize, ncols: usize) -> Self;
+
+    fn ones(nrows: usize, ncols: usize) -> Self;
+
+    fn fill(nrows: usize, ncols: usize, value: f64) -> Self;
+
+    fn shape(&self) -> (usize, usize);
+
+    fn v_stack(&self, other: &Self) -> Self;
+
+    fn h_stack(&self, other: &Self) -> Self;
+
+    fn dot(&self, other: &Self) -> Self;
+
+    fn slice(&self, rows: Range<usize>, cols: Range<usize>) -> Self;
+
+    fn approximate_eq(&self, other: &Self, error: f64) -> bool;
+
+    fn add_mut(&mut self, other: &Self);
+
+}