From a376a5221fd7af74ad9c951d918175593185e182 Mon Sep 17 00:00:00 2001
From: SamFerracin <samuele.ferracin@gmail.com>
Date: Wed, 27 Mar 2024 15:00:18 -0400
Subject: [PATCH] the walrus

---
 .../strategies/compactFock/inputValidation.py | 34 ++++++++++++++++++-
 mrmustard/physics/gaussian.py                 |  7 ----
 poetry.lock                                   |  8 ++---
 pyproject.toml                                |  2 +-
 tests/test_about.py                           |  2 +-
 5 files changed, 39 insertions(+), 14 deletions(-)

diff --git a/mrmustard/math/lattice/strategies/compactFock/inputValidation.py b/mrmustard/math/lattice/strategies/compactFock/inputValidation.py
index 237c7de59..b42158dbe 100644
--- a/mrmustard/math/lattice/strategies/compactFock/inputValidation.py
+++ b/mrmustard/math/lattice/strategies/compactFock/inputValidation.py
@@ -18,7 +18,39 @@
 from mrmustard.math.lattice.strategies.compactFock.singleLeftoverMode_grad import (
     fock_representation_1leftoverMode_grad,
 )
-from thewalrus._hafnian import input_validation
+
+def input_validation(A, rtol=1e-05, atol=1e-08):
+    """Checks that the matrix A satisfies the requirements for Hafnian calculation.
+    These include:
+    * That the ``A`` is a NumPy array
+    * That ``A`` is square
+    * That ``A`` does not contain any NaNs
+    * That ``A`` is symmetric
+
+    Args:
+        A (array): a NumPy array.
+        rtol (float): the relative tolerance parameter used in ``np.allclose``
+        atol (float): the absolute tolerance parameter used in ``np.allclose``
+
+    Returns:
+        bool: returns ``True`` if the matrix satisfies all requirements
+    """
+
+    if not isinstance(A, np.ndarray):
+        raise TypeError("Input matrix must be a NumPy array.")
+
+    n = A.shape
+
+    if n[0] != n[1]:
+        raise ValueError("Input matrix must be square.")
+
+    if np.isnan(A).any():
+        raise ValueError("Input matrix must not contain NaNs.")
+
+    if not np.allclose(A, A.T, rtol=rtol, atol=atol):
+        raise ValueError("Input matrix must be symmetric.")
+
+    return True
 
 
 def hermite_multidimensional_diagonal(A, B, G0, cutoffs, rtol=1e-05, atol=1e-08):
diff --git a/mrmustard/physics/gaussian.py b/mrmustard/physics/gaussian.py
index f5737c34a..7611660ed 100644
--- a/mrmustard/physics/gaussian.py
+++ b/mrmustard/physics/gaussian.py
@@ -18,8 +18,6 @@
 
 from typing import Any, Optional, Sequence, Tuple, Union
 
-from thewalrus.quantum import is_pure_cov
-
 from mrmustard import math, settings
 from mrmustard.math.tensor_wrappers.xptensor import XPMatrix, XPVector
 from mrmustard.utils.typing import Matrix, Scalar, Vector
@@ -660,11 +658,6 @@ def number_cov(cov: Matrix, means: Vector) -> Matrix:
     )
 
 
-def is_mixed_cov(cov: Matrix) -> bool:  # TODO: deprecate
-    r"""Returns ``True`` if the covariance matrix is mixed, ``False`` otherwise."""
-    return not is_pure_cov(math.asnumpy(cov))
-
-
 def trace(cov: Matrix, means: Vector, Bmodes: Sequence[int]) -> Tuple[Matrix, Vector]:
     r"""Returns the covariances and means after discarding the specified modes.
 
diff --git a/poetry.lock b/poetry.lock
index 830e825e7..aac3f8631 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -3509,13 +3509,13 @@ tests = ["pytest", "pytest-cov"]
 
 [[package]]
 name = "thewalrus"
-version = "0.21.0"
+version = "0.19.0"
 description = "Open source library for hafnian calculation"
 optional = false
 python-versions = "*"
 files = [
-    {file = "thewalrus-0.21.0-py3-none-any.whl", hash = "sha256:5f393d17fc8362e7156337faed769e99f15149040ef298d2a1be27f234aa8cb9"},
-    {file = "thewalrus-0.21.0.tar.gz", hash = "sha256:a8e1d6a7dea1e2c70aeb172f2dba1dfc7fabfa6e000c8ace9c5f81c7df422637"},
+    {file = "thewalrus-0.19.0-py3-none-any.whl", hash = "sha256:07b6e2969bf5405a2df736c442b1500857438bbd2afc2053b8b600b8b0c67f97"},
+    {file = "thewalrus-0.19.0.tar.gz", hash = "sha256:06ff07a14cd8cd4650d9c82b8bb8301ef9a58dcdd4bafb14841768ccf80c98b9"},
 ]
 
 [package.dependencies]
@@ -3785,4 +3785,4 @@ ray = ["ray", "scikit-optimize"]
 [metadata]
 lock-version = "2.0"
 python-versions = ">=3.9,<3.12"
-content-hash = "7d1198f211fdadc258ac6921669b414f48f6b61b279f81246aaef1f38b571b5c"
+content-hash = "d82541767cbc68915c992d627228835dda2c9b836b922219c71d7fb42d899555"
diff --git a/pyproject.toml b/pyproject.toml
index acc60cf5f..f9d7845c7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,7 +31,7 @@ grpcio = "1.60.0"
 numpy = "^1.23.5"
 scipy = "^1.8.0"
 numba = "^0.59"
-thewalrus = "^0.21.0"
+thewalrus = "^0.19.0"
 rich = "^10.15.1"
 matplotlib = "^3.5.0"
 ray = { version = "^2.5.0", extras = ["tune"], optional = true }
diff --git a/tests/test_about.py b/tests/test_about.py
index 0152d681f..487f42536 100644
--- a/tests/test_about.py
+++ b/tests/test_about.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """
-Unit tests for the :mod:`thewalrus` configuration class :class:`Configuration`.
+Unit tests for the ``about`` method.
 """
 
 import contextlib