From dd7675ff732695857d83da42ad41eaccac2e7ff9 Mon Sep 17 00:00:00 2001
From: Joseph Weston <joseph@weston.cloud>
Date: Thu, 1 Mar 2018 14:22:50 +0100
Subject: [PATCH] check that interpolated current goes to 0 at the boundaries
This checks that the padding around the counding box is sufficient.
---
kwant/tests/test_plotter.py | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/kwant/tests/test_plotter.py b/kwant/tests/test_plotter.py
index a5d06a36..c937e321 100644
--- a/kwant/tests/test_plotter.py
+++ b/kwant/tests/test_plotter.py
@@ -337,6 +337,12 @@ def rotational_currents(g):
return null_space_basis
+def _border_is_0(field):
+ borders = [(0, slice(None)), (-1, slice(None)),
+ (slice(None), 0), (slice(None), -1)]
+ return all(np.allclose(field[a, b], 0) for a, b in borders)
+
+
def test_current_interpolation():
## Passing a Builder will raise an error
@@ -423,6 +429,28 @@ def test_current_interpolation():
# 3rd value returned from 'linregress' is 'rvalue'
assert scipy.stats.linregress(np.log(data))[2] < -0.8
+ ## Test that the current is always identically zero at the boundaries of the box
+ syst = kwant.Builder()
+ lat = kwant.lattice.square()
+ syst[[lat(0, 0), lat(1, 0)]] = None
+ syst[(lat(0, 0), lat(1, 0))] = None
+ syst = syst.finalized()
+ current = [1, -1]
+
+ ns = [3, 4, 5, 10, 100]
+ abswidths = [0.01, 0.1, 1, 10, 100]
+ relwidths = [0.01, 0.1, 1, 10, 100]
+ for n, abswidth in itertools.product(ns, abswidths):
+ field, _ = kwant.plotter.interpolate_current(syst, current,
+ abswidth=abswidth, n=n)
+ assert _border_is_0(field)
+ for n, relwidth in itertools.product(ns, relwidths):
+ field, _ = kwant.plotter.interpolate_current(syst, current,
+ relwidth=relwidth, n=n)
+ assert _border_is_0(field)
+
+
+
@pytest.mark.skipif(not _plotter.mpl_available, reason="Matplotlib unavailable.")
def test_current():
--
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