From ac9b4369c8262b6462953c1c0251da3cd9c27f59 Mon Sep 17 00:00:00 2001
From: Anton Akhmerov <anton.akhmerov@gmail.com>
Date: Sun, 17 Dec 2023 00:14:05 +0100
Subject: [PATCH] raise a proper error in check_symmetry
closes #44
---
qsymm/hamiltonian_generator.py | 17 +++++++++++++----
qsymm/tests/test_hamiltonian_generator.py | 9 +++++++++
2 files changed, 22 insertions(+), 4 deletions(-)
diff --git a/qsymm/hamiltonian_generator.py b/qsymm/hamiltonian_generator.py
index ebda7e9..5e01e13 100644
--- a/qsymm/hamiltonian_generator.py
+++ b/qsymm/hamiltonian_generator.py
@@ -353,19 +353,28 @@ def check_symmetry(family, symmetries, num_digits=None):
In the case that the input family has been rounded, num_digits
should be the number of significant digits to which the family
was rounded.
- """
+ Raises
+ ------
+ ValueError
+ If the family does not satisfy the symmetry.
+ """
+ def fail():
+ raise ValueError(f'Member {member} does not satisfy symmetry {symmetry}.')
for symmetry in symmetries:
# Iterate over all members of the family
for member in family:
if isinstance(symmetry, PointGroupElement):
if num_digits is None:
- assert symmetry.apply(member) == member
+ if symmetry.apply(member) != member:
+ fail()
else:
- assert symmetry.apply(member).around(num_digits) == member.around(num_digits)
+ if symmetry.apply(member).around(num_digits) != member.around(num_digits):
+ fail()
elif isinstance(symmetry, ContinuousGroupGenerator):
# Continous symmetry if applying it returns zero
- assert symmetry.apply(member) == {}
+ if symmetry.apply(member) != {}:
+ fail()
def constrain_family(symmetries, family, sparse_linalg=False):
diff --git a/qsymm/tests/test_hamiltonian_generator.py b/qsymm/tests/test_hamiltonian_generator.py
index 3563fd5..28e574b 100644
--- a/qsymm/tests/test_hamiltonian_generator.py
+++ b/qsymm/tests/test_hamiltonian_generator.py
@@ -1,3 +1,5 @@
+from pytest import raises
+
import sympy
import numpy as np
import scipy.linalg as la
@@ -58,6 +60,13 @@ def test_check_symmetry():
else: # Symmetry commutes
assert np.allclose(Left - Right, 0)
+ # Test correctly raising a ValueError
+ with raises(ValueError):
+ check_symmetry(
+ [Model({1: np.eye(2)}, momenta=["k_x"])],
+ [chiral(1, np.diag([1, -1]))]
+ )
+
def test_bloch_generator():
"""Square lattice with time reversal and rotation symmetry, such that all hoppings are real. """
--
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