solve an equation system (wip)

nalgebra seems not to work to solve 4x3 matrix?

ndarray c dependencies error
rust-ndarray/ndarray-linalg#373

Cargo.toml

@@ -9,3 +9,5 @@ edition = "2021"
 # bevy = "0.14.0-rc.2"
 bevy = { version = "0.13.2" }
 nalgebra = { version = "0.32" }
+ndarray = "0.15.6"
+ndarray-linalg = "0.16.0"

src/alg.rs

@@ -1,18 +1,49 @@
 #[cfg(test)]
-use nalgebra::{Matrix3, Vector3};
+mod tests {
+    use nalgebra::{Matrix3, Vector3};
+    use ndarray::{array, Array1, Array2};
+    use ndarray_linalg::Solve;
+
+    #[test]
+    fn multiply_vector_matrix() {
+        let v = Vector3::new(1, 2, 3);
+
+        #[rustfmt::skip] 
+        let m = Matrix3::new(
+            11, 12, 13, 
+            21, 22, 23,
+            31, 32, 33
+        );
+
+        let res = m * v;
+
+        assert_eq!(res, Vector3::new(74, 134, 194));
+    }
+
+    #[test]
+    fn solve_equations_system() {
+        let a: Array2<f64> = array![[3., 2., -1.], [2., -2., 4.], [-2., 1., -2.]];
+        let b: Array1<f64> = array![1., -2., 0.];
+        let x = a.solve_into(b).unwrap();
+        assert!(x.abs_diff_eq(&array![1., -2., -2.], 1e-9));
 
-#[test]
-fn multiply_vector_matrix() {
-    let v = Vector3::new(1, 2, 3);
-
-    #[rustfmt::skip] 
-    let m = Matrix3::new(
-        11, 12, 13, 
-        21, 22, 23,
-        31, 32, 33
-    );
-
-    let res = m * v;
-
-    assert_eq!(res, Vector3::new(74, 134, 194));
+        // // Define your 4x3 matrix A and 4-dimensional vector b
+        // #[rustfmt::skip] 
+        // let a = Array2::from_shape_vec((4, 3), vec![
+        //     1.0, 2.0, 3.0,
+        //     4.0, 5.0, 6.0,
+        //     7.0, 8.0, 9.0,
+        //     10.0, 11.0, 12.0,
+        // ]).unwrap();
+
+        // let b = Array1::from(vec![10.0, 20.0, 30.0, 40.0]);
+
+        // // Solve the equation Ax = b
+        // // a.solv
+        // match a.solve_into(b) {
+        //     Ok(x) => println!("Solution x: {:?}", x),
+        //     Err(e) => println!("Error: {}", e),
+        // }
+    }
+
 }