From 448e45ffbed4176ed12da914302837887cff8937 Mon Sep 17 00:00:00 2001
From: Xin Hao <haoxinst@gmail.com>
Date: Wed, 19 Jun 2024 23:41:48 +0800
Subject: [PATCH 1/2] Add property method `is_hermitian` and `is_unitary`

---
 src/base/properties.rs | 19 +++++++++++++++++++
 tests/core/matrix.rs   | 18 ++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/src/base/properties.rs b/src/base/properties.rs
index ab0ceff2b..8041a7afb 100644
--- a/src/base/properties.rs
+++ b/src/base/properties.rs
@@ -119,4 +119,23 @@ where
         // TODO: improve this?
         self.clone_owned().try_inverse().is_some()
     }
+
+    /// Returns `true` if this matrix is hermitian.
+    #[inline]
+    #[must_use]
+    pub fn is_hermitian(&self) -> bool {
+        self.is_square() && self.transpose().conjugate().eq(self)
+    }
+
+    /// Returns `true` if this matrix is unitary.
+    #[inline]
+    #[must_use]
+    pub fn is_unitary(&self, eps: T::Epsilon) -> bool
+    where
+        T: Zero + One + RelativeEq,
+        T::Epsilon: Clone,
+    {
+        let r = self.transpose().conjugate() * self;
+        self.is_square() && r.is_identity(eps)
+    }
 }
diff --git a/tests/core/matrix.rs b/tests/core/matrix.rs
index 50c0e426a..523553113 100644
--- a/tests/core/matrix.rs
+++ b/tests/core/matrix.rs
@@ -201,6 +201,24 @@ fn identity() {
     assert!(!not_id3.is_identity(0.0));
 }
 
+#[test]
+fn is_hermitian() {
+    let a = Matrix2::new(1.0, 2.0, 3.0, 4.0);
+    let b = Matrix2::new(1.0, 2.0, 2.0, 1.0);
+
+    assert!(!a.is_hermitian());
+    assert!(b.is_hermitian());
+}
+
+#[test]
+fn is_unitary() {
+    let a = Matrix2::new(1.0, 2.0, 3.0, 4.0);
+    let b = Matrix2::new(0.0, 1.0, 1.0, 0.0);
+
+    assert!(!a.is_unitary(1.0e-7));
+    assert!(b.is_unitary(1.0e-7));
+}
+
 #[test]
 fn coordinates() {
     let a = Matrix3x4::new(11, 12, 13, 14, 21, 22, 23, 24, 31, 32, 33, 34);

From a991c13ddb9a3e22226cbbc6ee4ce37825dc27c2 Mon Sep 17 00:00:00 2001
From: Xin Hao <haoxinst@gmail.com>
Date: Mon, 1 Jul 2024 17:40:43 +0800
Subject: [PATCH 2/2] revert is_hermitian

---
 src/base/properties.rs | 7 -------
 tests/core/matrix.rs   | 9 ---------
 2 files changed, 16 deletions(-)

diff --git a/src/base/properties.rs b/src/base/properties.rs
index 8041a7afb..4a305481b 100644
--- a/src/base/properties.rs
+++ b/src/base/properties.rs
@@ -120,13 +120,6 @@ where
         self.clone_owned().try_inverse().is_some()
     }
 
-    /// Returns `true` if this matrix is hermitian.
-    #[inline]
-    #[must_use]
-    pub fn is_hermitian(&self) -> bool {
-        self.is_square() && self.transpose().conjugate().eq(self)
-    }
-
     /// Returns `true` if this matrix is unitary.
     #[inline]
     #[must_use]
diff --git a/tests/core/matrix.rs b/tests/core/matrix.rs
index 523553113..756278f4d 100644
--- a/tests/core/matrix.rs
+++ b/tests/core/matrix.rs
@@ -201,15 +201,6 @@ fn identity() {
     assert!(!not_id3.is_identity(0.0));
 }
 
-#[test]
-fn is_hermitian() {
-    let a = Matrix2::new(1.0, 2.0, 3.0, 4.0);
-    let b = Matrix2::new(1.0, 2.0, 2.0, 1.0);
-
-    assert!(!a.is_hermitian());
-    assert!(b.is_hermitian());
-}
-
 #[test]
 fn is_unitary() {
     let a = Matrix2::new(1.0, 2.0, 3.0, 4.0);