From 9245b5b9e923bb5f0f504aa4d44ced5aff74a919 Mon Sep 17 00:00:00 2001
From: Anton Akhmerov <anton.akhmerov@gmail.com>
Date: Mon, 18 Feb 2013 18:02:53 -0500
Subject: [PATCH] detect a faulty TranslationalSymmetry when it is created
---
kwant/lattice.py | 3 +++
kwant/tests/test_lattice.py | 3 +--
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/kwant/lattice.py b/kwant/lattice.py
index 1d4855b8..4b1b67d3 100644
--- a/kwant/lattice.py
+++ b/kwant/lattice.py
@@ -239,6 +239,9 @@ class TranslationalSymmetry(builder.Symmetry):
msg = "TranslationalSymmetry takes 1d sequences as parameters.\n" \
"See What's new in kwant 0.2 in the documentation."
raise ValueError(msg)
+ if np.linalg.matrix_rank(periods) < len(periods):
+ raise ValueError("Translational symmetry periods must be "
+ "linearly independent")
# A dictionary containing cached data required for applying the
# symmetry to different site groups.
self.site_group_data = {}
diff --git a/kwant/tests/test_lattice.py b/kwant/tests/test_lattice.py
index 45e0d279..dd5dac79 100644
--- a/kwant/tests/test_lattice.py
+++ b/kwant/tests/test_lattice.py
@@ -46,8 +46,7 @@ def test_translational_symmetry():
g2 = lattice.make_lattice(np.identity(2))
g3 = lattice.make_lattice(np.identity(3))
- sym = ts((0, 0, 4), (0, 5, 0), (0, 0, 2))
- assert_raises(ValueError, sym.add_site_group, g3)
+ assert_raises(ValueError, ts, (0, 0, 4), (0, 5, 0), (0, 0, 2))
sym = ts((3.3, 0))
assert_raises(ValueError, sym.add_site_group, g2)
--
GitLab