diff --git a/examples/3d_plot.py b/examples/3d_plot.py
index 8dcef1f40ca45a341d16afb8a208a9ed523e311a..ed8bccfeaa5bd7ea03cc6236f08a834a0c835f04 100644
--- a/examples/3d_plot.py
+++ b/examples/3d_plot.py
@@ -1,6 +1,6 @@
from math import sqrt
import scipy.sparse.linalg as sla
-import matplotlib.pyplot
+from matplotlib import pyplot
import kwant
sys = kwant.Builder()
@@ -9,11 +9,11 @@ lat = kwant.lattice.general([(1,0,0), (0,1,0), (0,0,1)])
t = 1.0
R = 10
-sys[(lat(x,y,z) for x in xrange(-R-1, R+1)
- for y in xrange(-R-1, R+1) for z in xrange(R+1)
+sys[(lat(x,y,z) for x in range(-R-1, R+1)
+ for y in range(-R-1, R+1) for z in range(R+1)
if sqrt(x**2 + y**2 + z**2) < R + 0.01)] = 4 * t
-sys[(lat(x,y,z) for x in xrange(-2*R, 2*R + 1)
- for y in xrange(-R, R+1) for z in xrange(-R, 0))] = 4 * t
+sys[(lat(x,y,z) for x in range(-2*R, 2*R + 1)
+ for y in range(-R, R+1) for z in range(-R, 0))] = 4 * t
sys[lat.neighbors()] = -t
sys = sys.finalized()
kwant.plot(sys)
diff --git a/examples/advanced_construction.py b/examples/advanced_construction.py
index dcfcfa92e6291fc577cd529732310b26d7b79c00..1d4806bacbd0eb268e0f9c7524a84b91cf98c0a1 100644
--- a/examples/advanced_construction.py
+++ b/examples/advanced_construction.py
@@ -1,6 +1,5 @@
"""An example of advanced system creation."""
-from __future__ import division
from math import tanh
from cmath import exp
import tinyarray as ta
@@ -48,7 +47,7 @@ def make_system(R):
def main():
sys = make_system(100)
- print kwant.smatrix(sys, 1.1, [0.1]).transmission(0, 1)
+ print(kwant.smatrix(sys, 1.1, [0.1]).transmission(0, 1))
if __name__ == '__main__':
diff --git a/examples/logo.py b/examples/logo.py
index c3dcb1f6e59cef8b4e7427895891767f2fb56043..941c613c8c803205d139a91bb24fd6826f960e0b 100644
--- a/examples/logo.py
+++ b/examples/logo.py
@@ -1,12 +1,10 @@
"""The script generating Kwant logo. In addition to Kwant it also needs Python
-image library (PIL)."""
+image library Pillow."""
-import Image
-import ImageFont
-import ImageDraw
+from PIL import Image, ImageFont, ImageDraw
import matplotlib
import numpy as np
-import scipy
+import scipy.misc
import kwant
def main():
@@ -86,7 +84,7 @@ def main():
# result is not too empty or not too dark.
out = np.zeros(textpos.shape)
for i, rho in enumerate(ldos**.2):
- x1, y1 = sys.site(i).tag
+ x1, y1 = sys.sites[i].tag
out[x1, y1] = rho
out = normalize_data(out)
diff --git a/examples/square.py b/examples/square.py
index c7df5d54200b247cb7584db9a7e0a9699ebf2f58..c61089cdb56c0f1f7472e4a22896befc2b37bf4b 100644
--- a/examples/square.py
+++ b/examples/square.py
@@ -2,7 +2,6 @@
kwant.Builder.
"""
-from __future__ import division
import numpy as np
from matplotlib import pyplot
import kwant
@@ -20,6 +19,7 @@ class Lead(object):
return square_selfenergy(self.width, self.t,
self.potential + fermi_energy)
+
class System(kwant.system.FiniteSystem):
def __init__(self, shape, hopping,
potential=0, lead_potentials=(0, 0),
@@ -56,7 +56,7 @@ class System(kwant.system.FiniteSystem):
edges[:shape[across], 1] += increment[along]
edges[shape[across]:, (0, 1)] = edges[:shape[across], (1, 0)]
g.add_edges(edges)
- for i in xrange(shape[along] - 2):
+ for i in range(shape[along] - 2):
edges += increment[along]
g.add_edges(edges)
self.graph = g.compressed()
@@ -66,7 +66,7 @@ class System(kwant.system.FiniteSystem):
# We have to use list here, as numpy.array does not understand
# generators.
interface = list(self.nodeid_from_pos((x, y))
- for y in xrange(shape[1]))
+ for y in range(shape[1]))
self.lead_interfaces.append(np.array(interface))
self.leads = [Lead(shape[1], hopping, lead_potentials[i])
@@ -85,7 +85,7 @@ class System(kwant.system.FiniteSystem):
return result
def nodeid_from_pos(self, pos):
- for i in xrange(2):
+ for i in range(2):
assert int(pos[i]) == pos[i]
assert pos[i] >= 0 and pos[i] < self.shape[i]
return pos[0] + pos[1] * self.shape[0]
@@ -98,8 +98,8 @@ class System(kwant.system.FiniteSystem):
def main():
sys = System((10, 5), 1)
- energies = [0.04 * i for i in xrange(100)]
- data = [kwant.smatrix(sys, energy).transmission(1, 0)
+ energies = [0.04 * i for i in range(100)]
+ data = [kwant.greens_function(sys, energy).transmission(1, 0)
for energy in energies]
pyplot.plot(energies, data)
diff --git a/examples/tests/test_square.py b/examples/tests/test_square.py
index 4d605368caa4f43660fbd27ea94587aecf09ef3f..f8654c98a50288f49d55a6b079029a959090d5aa 100644
--- a/examples/tests/test_square.py
+++ b/examples/tests/test_square.py
@@ -4,18 +4,18 @@ from numpy.testing import assert_almost_equal
def test_nodeid_to_from_pos():
s = square.System((3, 4), 1)
- assert_raises(StandardError, s.nodeid_from_pos, (0, -2))
- assert_raises(StandardError, s.nodeid_from_pos, (-1, 3))
- assert_raises(StandardError, s.nodeid_from_pos, (3, 1))
- assert_raises(StandardError, s.pos_from_nodeid, -1)
- assert_raises(StandardError, s.pos_from_nodeid, 12)
+ assert_raises(Exception, s.nodeid_from_pos, (0, -2))
+ assert_raises(Exception, s.nodeid_from_pos, (-1, 3))
+ assert_raises(Exception, s.nodeid_from_pos, (3, 1))
+ assert_raises(Exception, s.pos_from_nodeid, -1)
+ assert_raises(Exception, s.pos_from_nodeid, 12)
assert_equal(s.nodeid_from_pos((0, 0)), 0)
assert_equal(s.nodeid_from_pos(s.pos_from_nodeid(7)), 7)
assert_equal(s.pos_from_nodeid(s.nodeid_from_pos((2, 3))), (2, 3))
def test_hamiltonian():
sys = square.System((4, 5), 1)
- for i in xrange(sys.graph.num_nodes):
+ for i in range(sys.graph.num_nodes):
shape = sys.hamiltonian(i, i).shape
assert_equal(len(shape), 2)
assert_equal(shape[0], 1)
@@ -28,7 +28,7 @@ def test_hamiltonian():
def test_selfenergy():
sys = square.System((2, 4), 1)
- for lead in xrange(len(sys.lead_interfaces)):
+ for lead in range(len(sys.lead_interfaces)):
se = sys.leads[lead].selfenergy(0)
assert_equal(len(se.shape), 2)
assert_equal(se.shape[0], se.shape[1])