diff --git a/src/generate.rs b/src/generate.rs
index 2f5afe15..c1c34331 100644
--- a/src/generate.rs
+++ b/src/generate.rs
@@ -6,6 +6,7 @@ use std::ops::*;
 
 use super::convert::*;
 use super::error::*;
+use super::qr::*;
 use super::types::*;
 
 /// Hermite conjugate matrix
@@ -34,6 +35,33 @@ where
     ArrayBase::from_shape_fn(sh, |_| A::randn(&mut rng))
 }
 
+/// Generate random unitary matrix using QR decomposition
+///
+/// Be sure that this it **NOT** a uniform distribution. Use it only for test purpose.
+pub fn random_unitary<A>(n: usize) -> Array2<A>
+where
+    A: Scalar + RandNormal,
+{
+    let a: Array2<A> = random((n, n));
+    let (q, _r) = a.qr_into().unwrap();
+    q
+}
+
+/// Generate random regular matrix
+///
+/// Be sure that this it **NOT** a uniform distribution. Use it only for test purpose.
+pub fn random_regular<A>(n: usize) -> Array2<A>
+where
+    A: Scalar + RandNormal,
+{
+    let a: Array2<A> = random((n, n));
+    let (q, mut r) = a.qr_into().unwrap();
+    for i in 0..n {
+        r[(i, i)] = A::from_f64(1.0) + AssociatedReal::inject(r[(i, i)].abs());
+    }
+    q.dot(&r)
+}
+
 /// Random Hermite matrix
 pub fn random_hermite<A, S>(n: usize) -> ArrayBase<S, Ix2>
 where
diff --git a/tests/det.rs b/tests/det.rs
index 0acd7946..e0ce5e1f 100644
--- a/tests/det.rs
+++ b/tests/det.rs
@@ -100,46 +100,48 @@ fn det_zero_nonsquare() {
 
 #[test]
 fn det() {
-    macro_rules! det {
-        ($elem:ty, $shape:expr, $rtol:expr) => {
-            let a: Array2<$elem> = random($shape);
-            println!("a = \n{:?}", a);
-            let det = det_naive(&a);
-            let sign = det.div_real(det.abs());
-            let ln_det = det.abs().ln();
-            assert_rclose!(a.factorize().unwrap().det().unwrap(), det, $rtol);
-            {
-                let result = a.factorize().unwrap().sln_det().unwrap();
-                assert_rclose!(result.0, sign, $rtol);
-                assert_rclose!(result.1, ln_det, $rtol);
-            }
-            assert_rclose!(a.factorize().unwrap().det_into().unwrap(), det, $rtol);
-            {
-                let result = a.factorize().unwrap().sln_det_into().unwrap();
-                assert_rclose!(result.0, sign, $rtol);
-                assert_rclose!(result.1, ln_det, $rtol);
-            }
-            assert_rclose!(a.det().unwrap(), det, $rtol);
-            {
-                let result = a.sln_det().unwrap();
-                assert_rclose!(result.0, sign, $rtol);
-                assert_rclose!(result.1, ln_det, $rtol);
-            }
-            assert_rclose!(a.clone().det_into().unwrap(), det, $rtol);
-            {
-                let result = a.sln_det_into().unwrap();
-                assert_rclose!(result.0, sign, $rtol);
-                assert_rclose!(result.1, ln_det, $rtol);
-            }
-        };
+    fn det_impl<A, Tol>(a: Array2<A>, rtol: Tol)
+    where
+        A: Scalar<Real = Tol>,
+        Tol: RealScalar<Real = Tol>,
+    {
+        let det = det_naive(&a);
+        let sign = det.div_real(det.abs());
+        let ln_det = det.abs().ln();
+        assert_rclose!(a.factorize().unwrap().det().unwrap(), det, rtol);
+        {
+            let result = a.factorize().unwrap().sln_det().unwrap();
+            assert_rclose!(result.0, sign, rtol);
+            assert_rclose!(result.1, ln_det, rtol);
+        }
+        assert_rclose!(a.factorize().unwrap().det_into().unwrap(), det, rtol);
+        {
+            let result = a.factorize().unwrap().sln_det_into().unwrap();
+            assert_rclose!(result.0, sign, rtol);
+            assert_rclose!(result.1, ln_det, rtol);
+        }
+        assert_rclose!(a.det().unwrap(), det, rtol);
+        {
+            let result = a.sln_det().unwrap();
+            assert_rclose!(result.0, sign, rtol);
+            assert_rclose!(result.1, ln_det, rtol);
+        }
+        assert_rclose!(a.clone().det_into().unwrap(), det, rtol);
+        {
+            let result = a.sln_det_into().unwrap();
+            assert_rclose!(result.0, sign, rtol);
+            assert_rclose!(result.1, ln_det, rtol);
+        }
     }
     for rows in 1..5 {
-        for &shape in &[(rows, rows).into_shape(), (rows, rows).f()] {
-            det!(f64, shape, 1e-9);
-            det!(f32, shape, 1e-4);
-            det!(c64, shape, 1e-9);
-            det!(c32, shape, 1e-4);
-        }
+        det_impl(random_regular::<f64>(rows), 1e-9);
+        det_impl(random_regular::<f32>(rows), 1e-4);
+        det_impl(random_regular::<c64>(rows), 1e-9);
+        det_impl(random_regular::<c32>(rows), 1e-4);
+        det_impl(random_regular::<f64>(rows).t().to_owned(), 1e-9);
+        det_impl(random_regular::<f32>(rows).t().to_owned(), 1e-4);
+        det_impl(random_regular::<c64>(rows).t().to_owned(), 1e-9);
+        det_impl(random_regular::<c32>(rows).t().to_owned(), 1e-4);
     }
 }