From f659d101e7e5281cf04decc47b2676ff29ff395d Mon Sep 17 00:00:00 2001
From: Christoph Groth <christoph.groth@cea.fr>
Date: Thu, 27 Jul 2017 11:12:57 +0200
Subject: [PATCH] builder: split up _transfer_symmetry
---
kwant/builder.py | 59 ++++++++++++++++++++----------------------------
1 file changed, 25 insertions(+), 34 deletions(-)
diff --git a/kwant/builder.py b/kwant/builder.py
index 1e86c67d..fd8146a2 100644
--- a/kwant/builder.py
+++ b/kwant/builder.py
@@ -576,10 +576,7 @@ class BuilderLead(Lead):
The order of interface sites is kept during finalization.
"""
- syst = InfiniteSystem(self.builder, self.interface)
- _transfer_symmetry(syst, self.builder)
-
- return syst
+ return InfiniteSystem(self.builder, self.interface)
# Check that a modes/selfenergy function has a keyword-only parameter
@@ -1576,17 +1573,13 @@ class Builder:
`Symmetry` can be finalized.
"""
if self.symmetry.num_directions == 0:
- syst = FiniteSystem(self)
+ return FiniteSystem(self)
elif self.symmetry.num_directions == 1:
- syst = InfiniteSystem(self)
+ return InfiniteSystem(self)
else:
raise ValueError('Currently, only builders without or with a 1D '
'translational symmetry can be finalized.')
- _transfer_symmetry(syst, self)
-
- return syst
-
################ Finalized systems
@@ -1620,21 +1613,11 @@ def discrete_symmetry(self, args=(), *, params=None):
self._symmetries))
-def _transfer_symmetry(syst, builder):
- """Take a symmetry from builder and transfer it to finalized system."""
- def operator(op):
- if op is None:
- return
- return Density(syst, op, check_hermiticity=False)
-
- # Conservation law requires preprocessing to split it into eigenvectors
- # and eigenvalues.
- cons_law = builder.conservation_law
-
- if cons_law is None:
- syst._cons_law = None
-
- elif callable(cons_law):
+def _translate_cons_law(cons_law):
+ """Translate a conservation law from builder format to something that can
+ be used to initialize operator.Density.
+ """
+ if callable(cons_law):
@wraps(cons_law)
def vals(site, *args, **kwargs):
if site.family.norbs == 1:
@@ -1647,8 +1630,6 @@ def _transfer_symmetry(syst, builder):
return 1
return np.linalg.eigh(cons_law(site, *args, **kwargs))[1]
- syst._cons_law = operator(vals), operator(vecs)
-
elif isinstance(cons_law, collections.Mapping):
vals = {family: (value if family.norbs == 1 else
ta.array(np.diag(np.linalg.eigvalsh(value))))
@@ -1656,7 +1637,6 @@ def _transfer_symmetry(syst, builder):
vecs = {family: (1 if family.norbs == 1 else
ta.array(np.linalg.eigh(value)[1]))
for family, value in cons_law.items()}
- syst._cons_law = operator(vals), operator(vecs)
else:
try:
@@ -1667,11 +1647,22 @@ def _transfer_symmetry(syst, builder):
raise e # skip coverage
vals, vecs = cons_law, 1
- syst._cons_law = operator(vals), operator(vecs)
+ return vals, vecs
- syst._symmetries = [operator(symm) for symm in (builder.time_reversal,
- builder.particle_hole,
- builder.chiral)]
+
+def _init_discrete_symmetries(self, builder):
+ def _operator(op):
+ return Density(self, op, check_hermiticity=False)
+
+ if builder.conservation_law is None:
+ self._cons_law = None
+ else:
+ self._cons_law = tuple(map(
+ _operator, _translate_cons_law(builder.conservation_law)))
+ self._symmetries = tuple(None if op is None else _operator(op)
+ for op in [builder.time_reversal,
+ builder.particle_hole,
+ builder.chiral])
class FiniteSystem(system.FiniteSystem):
@@ -1765,7 +1756,7 @@ class FiniteSystem(system.FiniteSystem):
self._ham_param_map = _ham_param_map
self.lead_interfaces = lead_interfaces
self.symmetry = builder.symmetry
-
+ _init_discrete_symmetries(self, builder)
def hamiltonian(self, i, j, *args, params=None):
if args and params:
@@ -1989,7 +1980,7 @@ class InfiniteSystem(system.InfiniteSystem):
self.onsite_hamiltonians = onsite_hamiltonians
self._ham_param_map = _ham_param_map
self.symmetry = builder.symmetry
-
+ _init_discrete_symmetries(self, builder)
def hamiltonian(self, i, j, *args, params=None):
if args and params:
--
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